Power issue mid RPM

[RoyalRider05]

Just tested the TPS as per the manual. All rages are fine..so its not that.....

[snyper316]

There is a little hose, goes to the left front carb manifold. It's a vacuum hose for the spark advance I think. Often times this one gets cracked. It should have a restricter in it as well if I remember correctly.

Hey silly question is there supposed to be restrictor on first gen? I never seen one in my old hose but never looked either just replaced the hose.

 

Living life one curve after the other. Vroom scooting, thru the countryside.

[M61A1MECH]

There is a little hose, goes to the left front carb manifold. It's a vacuum hose for the spark advance I think. Often times this one gets cracked. It should have a restricter in it as well if I remember correctly.

 

Is this a true statement for the GEN-II Royal Star Ventures? I thought all of the ignition functions were taken care of by the ignition control module?

I know on my 07 with a DYNA 2K ignition module I could dial the spark advance with the dip switches on the DYNK 2K module.

 

I do not have my Venture anymore so no way to confirm the presence of vacuum advance.

[M61A1MECH]

So taking my previous post a small step forward, you may want to see if there is any one on the site that has a spare ignition module left over from a DYN2K install that they would loan you. You could try swapping out the ignition module to eliminate that as a possible suspect. Could be faulty electronics in the unit doing something funky at low RPMs. Not a typical fault, but it is an easy check if there is a spare module around some where.

[Freebird]

I have one. I don't want to sell it but would be willing to send it to your for your testing. I really doubt that yours is bad but it is always a possibility. I'm out of town right now but if you want to try it, I could put it in the mail on Monday. Just send me a PM with your address if you want to try it.

[bongobobny]

OOH!! OOH!!! Mr. Carter, Mr. Carter!! I know!!

 

Take a good look at those 4 rubber caps on the vacuum lines for when you sync the carbs!! I betcha one or more of those has cracks on them!!!

[V7Goose]

Going to tear into them this week. I did notice the Diaphragms (when pushing in the slide) seemed to be leaking air? Only 1 seemed very smooth in and out. Could that be the issue?

This makes no sense to me at all (pushing in the slide? leaking air?), but it does hint at where you problems probably are.

 

First of all, the issue IS your carbs, not the spark. While there are certain conditions that can cause a weak spark to fail good ignition (including low-RPM loads), this is so unlikely that I would personally totally ignore it at this point.

 

Your description of bogging on an open throttle until the RPMs build is a classic carb problem; typically low fuel availability, but also can be air related. CV carbs use differential air pressure on each side of the diaphragm to raise the needle and supply more fuel as the butterflies open. This differential air pressure comes from the carb vent lines that run to the front opening of the air filter. If those lines are plugged (can you say mud dauber wasp?) or kinked, the slides will not open correctly. And obviously, any damage to the diaphragms or seals around them (watch that little o-ring under the cap on the air passage) will certainly cause problems.

 

Despite your insistence that the carbs are clean, this type of problem can just as easily be caused by plugged air passages in the idle circuit. Do the RPMs drop off at idle as you close each air screw in turn? If not, they you HAVE a problem with the idle circuit in that carb. If the idle circuit does not work correctly, then the carb cannot provide the needed extra fuel in the transition to main jets as the butterflies are opened to let in more air. But the effect is rarely as bad as you describe, so although it might be a contributor, I doubt that it is your main problem.

 

Before you do anything else, you need to get that bike to idle properly at 1,000 RPM with all air and enriching circuits working well and the carbs synced. Then you have a chance of actually finding your real problem.

Edited February 16, 2017 by V7Goose

[RoyalRider05]

Yep! It sounds/feels like no fuel at all. Pulled the plugs(all 4 plugs)and they are ghost white. I can put on about 25% throttle and anymore it bogs and feels like its running on 1 cyclinder. Its like that all the way to WOT. I parked it late October and it was running just fine. It may very well be electrical... I will put the new parts together on the carbs this weekend. I got a new fuel pump and filter for the hell of it. Ill report back

 

Also- Idle is completely fine. I can rev from idle in neutral as well til i hit the rev limiter at WOT. Its only under load it bogs.....maybe that makes more sense?

 

My other theory is the bowl is not being filled enough. My fuel pump has 80,000 good miles on it. Last time i turned the key the points were very slow and it did not seem like it was pumping as fast as it normally does....So ill replace the pump since i have a new one and cross my fingers...

 

 

This makes no sense to me at all (pushing in the slide? leaking air?), but it does hint at where you problems probably are.

 

First of all, the issue IS your carbs, not the spark. While there are certain conditions that can cause a weak spark to fail good ignition (including low-RPM loads), this is so unlikely that I would personally totally ignore it at this point.

 

Your description of bogging on an open throttle until the RPMs build is a classic carb problem; typically low fuel availability, but also can be air related. CV carbs use differential air pressure on each side of the diaphragm to raise the needle and supply more fuel as the butterflies open. This differential air pressure comes from the carb vent lines that run to the front opening of the air filter. If those lines are plugged (can you say mud dauber wasp?) or kinked, the slides will not open correctly. And obviously, any damage to the diaphragms or seals around them (watch that little o-ring under the cap on the air passage) will certainly cause problems.

 

Despite your insistence that the carbs are clean, this type of problem can just as easily be caused by plugged air passages in the idle circuit. Do the RPMs drop off at idle as you close each air screw in turn? If not, they you HAVE a problem with the idle circuit in that carb. If the idle circuit does not work correctly, then the carb cannot provide the needed extra fuel in the transition to main jets as the butterflies are opened to let in more air. But the effect is rarely as bad as you describe, so although it might be a contributor, I doubt that it is your main problem.

 

Before you do anything else, you need to get that bike to idle properly at 1,000 RPM with all air and enriching circuits working well and the carbs synced. Then you have a chance of actually finding your real problem.

Edited February 16, 2017 by RoyalRider05

[RoyalRider05]

This is EXACTLY what my bike is doing.. (no this is not me)

 

 

[bongobobny]

If you learn one thing from this site, learn that Goose KNOWS what he is talking about!!

[snyper316]

While we in here talking carbs, I got a colortune and set all me screws to where I just see a flicker of orange/yellow is this the correct setting? Or should I turn the screws in just a tad?

 

Living life one curve after the other. Vroom scooting, thru the countryside.

[RoyalRider05]

Ok...all back together. I have the air mixture screw out 5.5 !!! It runs better. What is causing this??? This is driving me insane. If you Crack the throttle it sputters a bit then takes off. I have rebuilt the carbs..new fuel pump and filter. Any idea????

[Marcarl]

5.5 turns??? really? you have a problem.

Lets go over this a bit.

You had the carbs off, you took them all apart including the jet block, gaskets are all good, screws are good and snug, you took the air mixture needles out and made sure both passages are clean and then put them back in with the rubber o-ring on the end, a small washer and the spring on the threaded part and set them at 2.5 turns out. You then got the carbs lined back up so that they were all square and level, stuck them on the intakes and made sure they were seated properly and once they were you went back to check them again, after the install you warmed the engine, set the idle at about 900 and then did a carb sync with proper gauges.

Did you miss anything?

You did get the air-mixture screws out, right? they are in behind an aluminum cap and can't be seen unless you remove the cap.

Did you reset the floats according to specs? and do they shut off as planned.

[RoyalRider05]

Yes to all! I turned them back to 2.5 out and it still there...I'LL take video in a bit and post it up. I'm beside myself....this is the weirdest thing I have ever seen. Low RPM load it falls on its face.....high rpm...GOES when throttle is applied at WOT

 

 

 

 

5.5 turns??? really? you have a problem.

Lets go over this a bit.

You had the carbs off, you took them all apart including the jet block, gaskets are all good, screws are good and snug, you took the air mixture needles out and made sure both passages are clean and then put them back in with the rubber o-ring on the end, a small washer and the spring on the threaded part and set them at 2.5 turns out. You then got the carbs lined back up so that they were all square and level, stuck them on the intakes and made sure they were seated properly and once they were you went back to check them again, after the install you warmed the engine, set the idle at about 900 and then did a carb sync with proper gauges.

Did you miss anything?

You did get the air-mixture screws out, right? they are in behind an aluminum cap and can't be seen unless you remove the cap.

Did you reset the floats according to specs? and do they shut off as planned.

[RoyalRider05]

Synced carbs again....runs a bit better..but its still falling on its face past 25% throttle....i have a fuel delivery issue on ALL 4 cylinders. I have listed below what i have done....

 

-Carbs Cleaned (all jets are clear)

-Carbs re-built with new needle valves and diaphragms, air/fuel mixture screw (port was clean)

-New Fuel Pump

-New Fuel Filter

-Tested TPS and it falls into rage using a multi meter and the guide in the manual

 

Changes to bike during tear down: Harley Stock Pipes

 

What the heck am i missing here??????????

 

 

 

 

ALL 4 PLUGS ARE GHOST WHITE

[MiCarl]

You're still way lean. You're covering that up at idle by opening the screws so far but when you open the throttle you aren't getting enough fuel through the pilot system.

 

If you're certain they're as clean as they can be (and I'm never certain until I've done them myself at least twice!) then I'd replace the pilot jets. While I was at it I'd go up a size, maybe 2.

 

I had an ATV in the shop this winter that had obvious corrosion on the brass in the carburetor and I couldn't get the pilot jet clean enough to run well. I ended up going up a size when I replaced it and it was a dream. I had a motorcycle that was terribly cold blooded and went up a jet size and it's much nicer now. I'm very close to having a policy of throwing fatter jets in every time I do a carburetor.

Edited February 19, 2017 by MiCarl

[RoyalRider05]

I ended up ordering new jets. I went up sizes on all. My only last 2 options are a ECM TCI swap out and throttle position sensor (which already checks out ok) Thanks for the post

 

 

You're still way lean. You're covering that up at idle by opening the screws so far but when you open the throttle you aren't getting enough fuel through the pilot system.

 

If you're certain they're as clean as they can be (and I'm never certain until I've done them myself at least twice!) then I'd replace the pilot jets. While I was at it I'd go up a size, maybe 2.

 

I had an ATV in the shop this winter that had obvious corrosion on the brass in the carburetor and I couldn't get the pilot jet clean enough to run well. I ended up going up a size when I replaced it and it was a dream. I had a motorcycle that was terribly cold blooded and went up a jet size and it's much nicer now. I'm very close to having a policy of throwing fatter jets in every time I do a carburetor.

[Marcarl]

You are aware that there are 2 ports for the air-mixture screws right? The one at the end of the port is the easy one, just blow through it and it shows it's open. The other one is trickier, it's on the side and blow open that easy. You'll need to get a tube on the end of a carb cleaner can, insert it into the screw hole and then plug the little hole in the throat with your finger, then spray the carb cleaner. If it comes out into the throat you'll need to work at it until it goes out the side. If everything is open and working right, you'll not need to turn on the air-mixture screw more than one turn from 2.5. I use a vacuum gauge to see what I'm doing with the screw, I want to obtain as high a vacuum as possible. I don't think a carb-tune is accurate enough to do that.

[RoyalRider05]

When I get the new jets ill give this a try as well. I upped the jets as well. So hopefully this is the trick, because this is driving me insane....

 

You are aware that there are 2 ports for the air-mixture screws right? The one at the end of the port is the easy one, just blow through it and it shows it's open. The other one is trickier, it's on the side and blow open that easy. You'll need to get a tube on the end of a carb cleaner can, insert it into the screw hole and then plug the little hole in the throat with your finger, then spray the carb cleaner. If it comes out into the throat you'll need to work at it until it goes out the side. If everything is open and working right, you'll not need to turn on the air-mixture screw more than one turn from 2.5. I use a vacuum gauge to see what I'm doing with the screw, I want to obtain as high a vacuum as possible. I don't think a carb-tune is accurate enough to do that.

[MiCarl]

Something that just occurred to me:

 

Are your air cut off valves in good shape? Carburetor cleaner will ruin them. If the diaphragms are damaged they will let lots of extra air in.

[RoyalRider05]

Not sure what you are referencing. I have brand new diaphragms

 

Something that just occurred to me:

 

Are your air cut off valves in good shape? Carburetor cleaner will ruin them. If the diaphragms are damaged they will let lots of extra air in.

[MiCarl]

Ok, if you don't know what they are you've got a problem. They need to be opened up to properly clean the carburetor.

 

Part #7 .

 

[RoyalRider05]

Opened up...cleaned them up and no holes or tears in the diaphragms..... The carbs are fine..i ran cleaner through EVERY circuit there is and watched it dribble from the other sides/ or into the barrel of the carb. I sprayed down the main hole where the needle is as well and it came out the main pilot. I plugged up the air/fuel hole and it came out the pilot jet. SOOO..im now leaning to an ECM or TPS issue....

 

 

Ok, if you don't know what they are you've got a problem. They need to be opened up to properly clean the carburetor.

 

Part #7 .

 

http://www.venturerider.org/forum/attachment.php?attachmentid=108505

Edited February 21, 2017 by RoyalRider05

[sldunker]

If this bike ran good back in October and the only change you did to it was install harley mufflers, I guess that is were I would go back to. I would put stock mufflers back on and try it. If all your plugs are white then the problem is affecting all 4 cyclinders at the same time. Usually if carbs are dirty you will always have one or two carbs that arn't to bad and plugs will read different. I am starting to believe problem is outside of carbs, but where.

[Marcarl]

Well I would say we beat the carb thing to death, so maybe it is the exhaust. My Spyder runs good, want to try that exhaust?