87 VR, carb problem

Hi Folks,

My name is Gearhead Jeremy, and I've been an absentee member...I used to frequent this forum a lot. 3.5 years ago I decided that is was time for a change and bought a 2005 Suzi VStrom DL650, really enjoying that. I kept the VR because I just can't let stuff go, and I like it. But my wife's not riding with me any more, and having two bikes just isn't fun to keep up with for me anymore.

The other twist is that 3 years ago, before I made this decision, I took my carbs apart (about 120k miles). I've had the bike since 45k miles, and I've never needed to go into the carbs other than the diaphragms. It had a slight stumble under certain circumstances and I thought I'd clean them out and see what I found in there. I got one carb apart, and then they sat on my bench under a rag untouched for 3 years. But that's just silly, and it's time to get this kitten purring again and let someone else enjoy it. I got it back running, but it's not right. I'll list what its symptoms first, then what I did to the carbs.

Also, this is related to two other threads in which I asked simple questions about specific aspects:

https://www.venturerider.org/forum/showthread.php?141444-87-VR-carbs-rubber-plugs-in-jet-block

https://www.venturerider.org/forum/showthread.php?141443-87-VR-Coasting-Enricher-system-is-it-necessary

SYMPTOMS - Lean idle and just off-idle

1) Very dependent on choke for good throttle response until it's really good and hot. I'm in Tucson, so I mean HOT!

2) Pilot screws are set at ridiculous settings for best idle - two carbs at 5 turns, and two at 3 turns. Before the rebuild, I had tuned them at some point in the distant past and they were all at or under 2 turns.

3) Even when it's hot and taking throttle, standing start with the clutch still doesn't feel quite right, a little hesitant. Before it's hot, if I try to take off quick with say 1/4 to 1/2 throttle, it drops cylinders / misfires for a second or so.

4) Runs smooth and goes like a bat out of hell once in the mid-range and upper RPMs. Man, this is a nice riding bike.

5) It wasn't acting like this before I took the carbs off.

WHAT I DID

1) Replaced worn slides / compromised diaphragms and ovaled-out needle jets / emulsion tubes. I thought for sure that would be the ticket.

2) Found one or two damaged Coasting Enricher diaphragms. Not wanting to spend the bucks for them and thinking their ONLY purpose is to stop the popping on overrun, I plugged the vacuum passages in the caps above these diaphragms to disable the system and stop the vacuum leak. See other thread. I've done this before on a Virago.

3) Carbs overall were quite clean inside. They are cleaner now.

4) Jet Block rubber plugs, two per carb, are pretty hard and don't fit tight in the holes, maybe shrunk. See other thread. I didn't know what they were for and reused them, I am thinking this is likely my problem as maybe it can suck fuel in thru ways it's not supposed to. Not sure how that makes my pilot circuit lean, but sometimes these things are not intuitive.

5) I replaced the bowl o-rings / gaskets, but did not replace the jet block or choke gaskets, or the needle jet o-ring (by the jet block gasket). They seemed OK, and I've had great luck just cleaning old parts in the past.

6) Checked the spark plugs, they look normal.

7) Drained old fuel and put in new.

8) Checked for vacuum leaks by spraying stuff around the boots with engine idling. No leaks.

UPDATE TO THINGS DONE 2019-07-29

9) Took it all apart again, found nothing noteworthy. Double-ensured everything was clean, especially the pilot jets and full circuits

10) Rubber jet block plugs were swollen with fuel, probably not leaking. I treated them and the needle jet o-rings with wintergreen oil which made everything supple again - magic.

11) Replaced jet block gaskets

12) Put it all back together. No change to symptoms.

13) Carb#4 fuel level is erratic on the low side when idling.

Did I mention it wasn't running like this before I tore the bike down? My garage is fully enclosed and insulated, and my kids are grown, so the bike and parts were undisturbed all that time. I did drain the carbs 3 years ago before abandoning them, which fits into my "shrunken rubber plugs" theory; maybe they need the fuel immersion to keep them swelled up?

So - carb geniuses out there - do these symptoms speak to you?

Thank you!!!!!!!!

Jeremy

Maybe I didn't read closely enough or you just used a different term for them but did you clean all the jets really well? I'm mot talking about just soaking them but running a small wire through them and soaking and rinsing them again and then repeat a couple of times. I know of several here who have cleaned their carbs and still not gotten the jets unplugged until finally running a wire through them.

Thanks for the response. Yes and no. I didn't use wire. I did clean each jet by spraying carb cleaner thru, blowing compressed air thru, then holding it up to the light so that I could see the hole and ensure that it looked round and clear. This included several angles for the emulsion tubes with the side holes.

I've encountered what you describe on bikes that sat with fuel in the carbs. Fortunately that wasn't the case here and everything was pretty clean. Also, it wasn't doing this before, so clogged jets were fairly unlikely.

Thx! Jeremy

check the carb holders and everything else for vacuum leaks.

Again here you can use the Mr.Gasket to secure your plugs, keep it thin by art brushing it over the plug and make sure it stays in position while curing.

The jet block gasket is not expensive and last I check the market was flooded with them, should be replaced. Each port is separated by a ring that must compress the gasket.

Now 5 turns either suggest your jets are to small or.... they are not clean those are your 2 options... A vacuum leak will show up in heat, fast idles and hanging rpm's... as tho the throttle plates are was still open!

How ever, I would bet that your compression is off? This may seem confusing but the slow to heat is not just related to the pilots, they need the heat from compression as well or the cylinders keep running under wet cold conditions! So in other words soak the rings after reading compression, then you may find that one or two jugs are coming out a touch over max standard, and then you can deal with that after.

How I would proceed: Carbs then compression test, then soak while tending to carbs. PS. don't forget to check the airbox boot seals, they too can take a touch of RV sealant at the lower mating surface of the box.

Patch

Hey Patch,

What is this Black Mr. Gasket sealant? The only one that comes up easily in a search is this:

https://www.amazon.com/Mr-Gasket-78080G-RTV-Sealant/dp/B071VZ9CQY

This appears to be regular RTV silicone, which is not usually fuel resistant. Is the black stuff made to be immersed in fuel?

Also, would you mind clarifying the following?

"So in other words soak the rings after reading compression, then you may find that one or two jugs are coming out a touch over max standard, and then you can deal with that after.

How I would proceed: Carbs of then compression test, then soak while tending to carbs. "

What do you mean by soak the rings? Thanks!

Jeremy

As for vacuum leaks, that's a great idea. I did spray the whole area down with the bike idling, first with water, then with carb cleaner. No change in idle, so I don't think there are vacuum leaks.

Oh, I also checked the fuel levels in the bowls, which are spot-on.

Jeremy

Hey Patch,

 

What is this Black Mr. Gasket sealant? The only one that comes up easily in a search is this:

https://www.amazon.com/Mr-Gasket-78080G-RTV-Sealant/dp/B071VZ9CQY

 

This appears to be regular RTV silicone, which is not usually fuel resistant. Is the black stuff made to be immersed in fuel?

 

Also, would you mind clarifying the following?

"So in other words soak the rings after reading compression, then you may find that one or two jugs are coming out a touch over max standard, and then you can deal with that after.

 

How I would proceed: Carbs of then compression test, then soak while tending to carbs. "

 

What do you mean by soak the rings? Thanks!

 

Jeremy

https://www.permatex.com/products/gasketing/optimum-gasket-makers/permatex-optimum-black-gasket-maker/

Do a search here on the forum "A case for fogging" you will find the instructions there.

I recomend the compression test first.

here's the link

https://www.venturerider.org/forum/showthread.php?137296-A-Case-for-Fogging&highlight=case+fogging

How are you making out?

I'd like to suggest you also check the Pilot air jet while you're at it. Should be page 5-6 note 16, item 1

Patch

Hey Patch,

Page 5 - 6 etc of what document?

The pilot air jet is the 170 size jet under the slide diaphragm, yes? They're fine. I took the carbs COMPLETELY apart and cleaned everything. And they really weren't dirty to begin with, since this bike never sat unused except after the carbs were off and drained, so there was literally NO crud found in there. I realize this is unusual.

I ordered some Wintergreen Oil, and I'm gonna re-rubberize the plugs (and the coolant plugs on the sides of the block) with that Wintergreen / alcohol mix. I don't have the oil yet, but maybe I'll go pull the carbs off today. It should be quicker the second time, plus I don't have to do any of the additional cleaning / fixing I did the first time around. This is my pep talk to myself

Jeremy

Hey Patch,

 

Page 5 - 6 etc of what document?

 

 

Jeremy

Of the service manual.

Update:

I pulled the carbs back off and stripped them down. The black rubber jet block plugs had been hard and loose-fitting, I was going to recondition or replace them as discussed in a separate thread, thinking this was likely my problem. But when I got in there I found that the exposure to fuel has made them swell and get softer, such that they now fit snugly in the jet block holes. I'll still do the wintergreen oil reconditioning, but I don't really think they were leaking.

I pulled the jets out of one of the blocks and verified that they are still clean and clear, along with the jet block itself.

I found that I had apparently neglected to tighten the brass screw that secures the needle jet to the jet block in one carb - DOH. Not good, but I don't think that accounts for my entire problem.

Jet block gaskets - as I said before, I didn't replace them. I've generally had good luck reusing such gaskets as long as they go back precisely where they came from, which these do because they are stuck to the jet block, and there are precision alignment features. But since I'm running out of candidates for the cause of my problem, I'm thinking I need to get new ones. Spendy lil buggars. I thought about trying to make them, but that sounds...taxing...they are pretty precise.

Pilot air jet No 1, Manual p5-6 Note 16 - I had these (and all the jets) out. Sprayed a ton of carb cleaner and air through the passages, and cleaned the jets, sighted thru them to a light source and verified that the hole in the jets is round and clear.

I haven't done anything with the compression or rings. I can check the comp, but it was fine 3 years ago, and it has sat in my insulated, fully enclosed garage with the carbs removed, so I have a hard time believing something changed there.

So....what else to look for while I'm back in the carbs?

Thanks, Jeremy

Update:

 

I pulled the carbs back off and stripped them down. The black rubber jet block plugs had been hard and loose-fitting, I was going to recondition or replace them as discussed in a separate thread, thinking this was likely my problem. But when I got in there I found that the exposure to fuel has made them swell and get softer, such that they now fit snugly in the jet block holes. I'll still do the wintergreen oil reconditioning, but I don't really think they were leaking.

 

I pulled the jets out of one of the blocks and verified that they are still clean and clear, along with the jet block itself.

 

I found that I had apparently neglected to tighten the brass screw that secures the needle jet to the jet block in one carb - DOH. Not good, but I don't think that accounts for my entire problem.

 

Jet block gaskets - as I said before, I didn't replace them. I've generally had good luck reusing such gaskets as long as they go back precisely where they came from, which these do because they are stuck to the jet block, and there are precision alignment features. But since I'm running out of candidates for the cause of my problem, I'm thinking I need to get new ones. Spendy lil buggars. I thought about trying to make them, but that sounds...taxing...they are pretty precise.

 

Pilot air jet No 1, Manual p5-6 Note 16 - I had these (and all the jets) out. Sprayed a ton of carb cleaner and air through the passages, and cleaned the jets, sighted thru them to a light source and verified that the hole in the jets is round and clear.

 

I haven't done anything with the compression or rings. I can check the comp, but it was fine 3 years ago, and it has sat in my insulated, fully enclosed garage with the carbs removed, so I have a hard time believing something changed there.

 

So....what else to look for while I'm back in the carbs?

 

Thanks, Jeremy

All right lets review.

First I'll touch on the compression: compression should be the first check before rebuild of carbs. The compression readings over 5ish strokes speak volumes to the experienced fellow. The ceiling of of the rings represents the overall condition of the pump/engine.

A low compression verses a slow to build compression means bottom line the rings are not ceiling/locking. There can be valve seat issues as well and that is proved separately... Moving past valve issues what we need to know is the low standard expectations, will she pull enough low pressure/vacuum to draw fuel and atomize?

Storage is a crank that doesn't get to rotate; the pistons and rings remain parked where they stopped. If a piston x 2 stops at the bottom of the jug it is close to or in the taper, if it stops at the top then it is close to the carbon ring at the top of the jug. 1 or a set of valves are open and the others close, either way conditions are not equal!

The pilot circuits: What can effect them, we covered blockage, we covered main air jet, we covered plugs, we covered gaskets.

So what bench setting mark did you use when you put the carbs together?

Does she run or maintain idle when choke is on?

Patch

So what bench setting mark did you use when you put the carbs together?

What setting are referring to? Fuel level? That is right on spec.

Does she run or maintain idle when choke is on?

First post has a detailed description of the bike's behavior, but to summarize: Choke does in fact solve all the problems, so I know it's lean. When it's kinda warm it will idle w/o choke, but remember I have the pilots out 3-5 turns which isn't right. And it doesn't take initial throttle very well, a little stumbling. When it's "good n hot" it almost runs right, but still doesn't quite respond correctly right off idle, you feel this when taking off from a standing stop. Mid range and top end are great.

I'll check compression when I can.

Thanks Patch.

What setting are referring to? Fuel level? That is right on spec.

 

 

First post has a detailed description of the bike's behavior, but to summarize: Choke does in fact solve all the problems

so I know it's lean. When it's kinda warm it will idle w/o choke, but remember I have the pilots out 3-5 turns which isn't right. And it doesn't take initial throttle very well, a little stumbling. When it's "good n hot" it almost runs right, but still doesn't quite respond correctly right off idle, you feel this when taking off from a standing stop. Mid range and top end are great.

 

I'll check compression when I can.

 

Thanks Patch.

Choke does in fact solve all the problems : the enricher is below the throttle plates!

so I know it's lean: not necessarily and yes at the same time. The problem becomes that the cycle is lean or starved in this case of both air and fuel!

So look, you must bring to spec the carb x 4 each must work as designed; then you must bench set the throttle plates before installing and after you assemble them, or you play with the devil. I am going by memory here but as I recall on this model it is the second port up from the bottom that the bottom of the plate should intersect... Now some will say the top or the bottom of the plate, no argument from me on either, it will start and run either way then you dial up or down your rpm to suit!

I set the mix pilot at 1 to 1 1/4 turns out when I know I am jetted correctly, if im running a jet scale to see what works best then I might change the initial setting! Start at 1 1/4 turn after you bench set the throttle plates!

This will work providing the carb is in proper order, no leaks anywhere, fuel or air.

Hey Patch, I did a carb sync by vacuum with a set of carb mercury sticks once the engine was warm. Set the idle to 1000 rpm. Does this not accomplish the same?

Hmm, I could say yes but each turn of the set screws effect the outcome. Not sure I have the english to explain what or where the balances lie.

on

First we must expect a starting point; So I have a unique tool I use for carbs, cars, bikes or benching experiments. I can run a plenum completely off scale yet hit posted standards.

If you're still following then here is what I am trying to say, Vacuum is a chase,,,, one overly high will compensate for one short of expectation. When balancing 4 into one harmonious unit, you need start off an equal platform!

At throttle yes, I would find little argument at idle (regarding sync) tho/ and while vac is @ the highest, its a crap shoot because of the other variables that work against the camouflage of base vacuum...

So to answer the question, I say start the process off @ standard, then we have the answers..

I am a high performance guy who enjoys combustion, could care less about the rest, so it has to fit my logic.

I've asked Puc to join the conversation, he usually makes sense of my translations so lets wait for him to chime in..

Maybe I didn't read closely enough or you just used a different term for them but did you clean all the jets really well? I'm mot talking about just soaking them but running a small wire through them and soaking and rinsing them again and then repeat a couple of times. I know of several here who have cleaned their carbs and still not gotten the jets unplugged until finally running a wire through them.

Thanks for the response. Yes and no. I didn't use wire. I did clean each jet by spraying carb cleaner thru, blowing compressed air thru, then holding it up to the light so that I could see the hole and ensure that it looked round and clear. This included several angles for the emulsion tubes with the side holes.

 

I've encountered what you describe on bikes that sat with fuel in the carbs. Fortunately that wasn't the case here and everything was pretty clean. Also, it wasn't doing this before, so clogged jets were fairly unlikely.

 

Thx! Jeremy

IMHO, it almost impossible to completely clear jets with just compressed air and spray carb cleaner cause you really dont know if what your seeing at the end is actual sized correctly jetting. At a minimum a piece of wire trimmed off a wire brush and then carefully scraping the jets wall is prudent IMHO.. I have been using Jet Cleaners for a good while - they are very similar to Torch Tip Cleaners if you are familiar with those? They have a knurled surface on them that allows you to clean at a smaller size and visually see if your removing crud as you work. I would also advise spraying carb cleaner into the low speed jet housing in the carb body and make sure the carb spray is coming out of the tiny delivery hole(s) so you know that the passages thru the body are open.

As for vacuum leaks, that's a great idea. I did spray the whole area down with the bike idling, first with water, then with carb cleaner. No change in idle, so I don't think there are vacuum leaks.

 

Oh, I also checked the fuel levels in the bowls, which are spot-on.

 

Jeremy

What setting are referring to? Fuel level? That is right on spec.

 

 

First post has a detailed description of the bike's behavior, but to summarize: Choke does in fact solve all the problems, so I know it's lean. When it's kinda warm it will idle w/o choke, but remember I have the pilots out 3-5 turns which isn't right. And it doesn't take initial throttle very well, a little stumbling. When it's "good n hot" it almost runs right, but still doesn't quite respond correctly right off idle, you feel this when taking off from a standing stop. Mid range and top end are great.

 

I'll check compression when I can.

 

Thanks Patch.

I like to use Propane for testing for vacuum leaks.. Just take a small propane torch, open the valve but dont light it and shoot the gas stream around the intakes with the motor idling.. If she is pulling air - I generally can hear a tone change or idle change. You could be (and probably are) dealing with only one,, maybe two, cylinder's not functioning properly. Start it up from cold using the choke, tempt test each header as it warms up and see if you can find one that is not coming up to temp to isolate the issue. These bikes tend to be fairly cold blooded and dont run well until they warm up normally but, due to Mom Yam's choice of spaconrk plug size ("D" plugs), the plugs will easily blacken and become fouled if the choke is over used = move the choke off as it warms up and your monitoring the header heat. Hesitations/stumbles right off the bottom are not always fuel/air - carb issues.. As a matter of fact, I have encountered exactly what you wrote (see Red above) numerous times thru the years and more times then not - discovered the issue was ignition related. Blackened plugs, carbon tracking on plug caps, the notorious corrosion at the plug cap/wire connection, cap gone to high resistance, corrosion at plug wire/coil pack connection and even corrosion at the pins on the TCI.. Another area to check is the vacuum at the spark advance module and module itself.. IMHO, just because adding fuel to the fuel/air mixture via the enricher circuit causes it to run better does not necessarily mean it is carb related. In that you have already been thru the carbs and know they are up to snuff - I would consider looking elsewhere..

Thanks Puc and Patch.

I have torch tip cleaners. But I've also read that they can scratch the bore of a brass jet and that can affect the flow metering properties. I could try them gently. It's just that I've done a fair number of these before, and I've seen plugged jets, and the light thru the hole in the center looks either funny or non-existent. That said, I have the carbs stripped down again so I can double-check and gently try the tip cleaners. I ordered new jet block gaskets as well, and will re-rubberize the plugs. I did the thing where I sprayed carb cleaner in the idle jet hole, but I'll do that again also to ensure it's getting thru the two holes in the carb bore by the throttle plate.

It's weird to me that all 4 carbs have to be set with the pilots extra far out, 3 -5 turns, where before it ran best at 1.5 - 2 turns. I did the TCI relocation to the top of the airbox years ago, I can check that connection. And I'll check the compression and plug wires. Again, it's hard to fathom that the problem is anywhere other than the carbs because I didn't touch anything else, the fuel was drained, and it sat in a benign environment.

I'll keep at it. Thanks again.

Jeremy

Thanks Puc and Patch.

 

I have torch tip cleaners. But I've also read that they can scratch the bore of a brass jet and that can affect the flow metering properties. I could try them gently. It's just that I've done a fair number of these before, and I've seen plugged jets, and the light thru the hole in the center looks either funny or non-existent. That said, I have the carbs stripped down again so I can double-check and gently try the tip cleaners. I ordered new jet block gaskets as well, and will re-rubberize the plugs. I did the thing where I sprayed carb cleaner in the idle jet hole, but I'll do that again also to ensure it's getting thru the two holes in the carb bore by the throttle plate.

 

It's weird to me that all 4 carbs have to be set with the pilots extra far out, 3 -5 turns, where before it ran best at 1.5 - 2 turns. I did the TCI relocation to the top of the airbox years ago, I can check that connection. And I'll check the compression and plug wires. Again, it's hard to fathom that the problem is anywhere other than the carbs because I didn't touch anything else, the fuel was drained, and it sat in a benign environment.

 

I'll keep at it. Thanks again.

 

Jeremy

Thats why I suggest getting actual Carb Jet cleaners such as these: https://www.ebay.com/itm/AIFUDA-Set-of-3-Carburetor-Carbon-Jet-Cleaner-13-Wire-Torch-Tip-Cleaner-Tool-2/163408329640?epid=2296693244&hash=item260be53ba8:g:mVgAAOSwgVJcAo6I

So you can use a smaller wire cleaner than the actual jet size. By doing so you can run the wire in and monitor what, if anything, is captured in the wires knurled cleaning area and if you pick up any brass you know your to deep. It's takes a little getting use to using them cause you dont want to oblong or oversize the jetting but it is very doable IMHO. Another thing that I have used for years is a ChemDip dip tank like this:https://www.ebay.com/itm/Berryman-New-0996-Chem-Dip-Carburetor-and-Parts-Cleaner-96-oz-Can-with-Basket/332798651243?_trkparms=ispr%3D1&hash=item4d7c586b6b:g:EqcAAOSwvoNblLcS&enc=AQADAAAB4KX%2FKt4E1xf3SDqEdBclaYbes89adbLV33TB8MwLD8p4aG97GaVyUYZVZnynYbp3yEjyH5IKjWVnZvOBvlJr5VGpxmJ0ir5m2Q5EYha39n4nEsocDLVP1toADfJ0n2TCmxc5jSUjoZ3mDbzVpCi44rX4BZylEsmU7saxvTJ3IaawJp58swPxhsTbYdkp9AaDjUxJeeaBm448vEoeoa0LpU9zQOCUt9DfKvBCmIi35NadqICllAFp9g6SSI%2BuVEqNhQxxAPkgo%2Bie0cZoXt%2Bu0bdXHwav0DiIcJ16X3vUuqiT7B1iMjAQwR2ie7VzBBIhkaQ6FHnNvi%2FA3%2B%2FUHBF6uu8XIEdUiOXps5%2FZ94wtQ4j1dr%2BeIP%2BkZwd9A4erDe2ae3O95aNMaCK%2Fgw%2B1v3Uqgw%2Fd6FiRLqVnBNZhApsB6DOMLprOAWhZRnHhF3UslHP2RYvbmajzxfFGwPcbJMmfIMWZEDk9SDQ7LWTOof3ZtHEPf342wkYmVfVTPZ%2Feiu0LtlyC3eaI9bEWHzw%2FKLl3vTgBbhSNO%2FV7uyNPD0Z%2Bh0QTmcOlEt%2BrMHIHyIdLAB1KKZVEVg05k7RsDV9aDnN460jcjqflghLDMVfYjT7EFQuRs1xDA6oAMLm4dyFdZSsK1Q%3D%3D&checksum=3327986512435ad17e050f0140a3ae6690e35e9e0347

I have found this to be the only thing out there that will actually loosen stuff in clogged jetting. Spray cleaner does an ok job but no where near as effectively as Chem Dip and I have had no positive results with soaking in pure "in tank" cleaners such as Sea Foam.

By the way @Gearhead,, you are more than welcome on the advice.. Glad to help!

These bikes are notorious for the spark plug wires corroding where they are connected to the plug caps and the coils. Unscrew the spark plug caps and see if the copper wire cores are green with corrosion. If so, cut off a half inch or more to get to clean copper wire and reinstall. Or replace the wires. Also, check the caps for resistance. Should be 9k to 10k ohms if stock. NGK replacements are typically 5k ohms. You may have a spark problem instead of a carb problem.

These bikes are notorious for the spark plug wires corroding where they are connected to the plug caps and the coils. Unscrew the spark plug caps and see if the copper wire cores are green with corrosion. If so, cut off a half inch or more to get to clean copper wire and reinstall. Or replace the wires. Also, check the caps for resistance. Should be 9k to 10k ohms if stock. NGK replacements are typically 5k ohms. You may have a spark problem instead of a carb problem.

:sign yeah that: followup on this,, just do it!!

Not to say it shouldn't be checked but,, ignition misfires would show up where he says he isn't having problems.

Just sayinnn

What setting are referring to? Fuel level? That is right on spec.

 

 

First post has a detailed description of the bike's behavior, but to summarize: Choke does in fact solve all the problems, so I know it's lean. When it's kinda warm it will idle w/o choke, but remember I have the pilots out 3-5 turns which isn't right. And it doesn't take initial throttle very well, a little stumbling. When it's "good n hot" it almost runs right, but still doesn't quite respond correctly right off idle, you feel this when taking off from a standing stop. Mid range and top end are great.

 

I'll check compression when I can.

 

Thanks Patch.

Not to say it shouldn't be checked but,, ignition misfires would show up where he says he isn't having problems.

Just sayinnn

""When it's "good n hot" it almost runs right, but still doesn't quite respond correctly right off idle, you feel this when taking off from a standing stop. Mid range and top end are great.""i

is exactly what I have experienced with faulty wires/caps, fouled plugs ect. Patch and that corrusion that Sky mentioned is present and cleaning em up with a 1/4 inch snip is a big part of the solution to correcting the stumble in many cases, especially coming up off idle when the engine is under a load.. It is amazing what doing that and a new set of plugs gapped to 32 thou will do for erradicating a right off idle stumble IMHO. Definitely something that is easy to check.