Still running hot, any advice?

[circa1968]

After changing coolant and thermostat, my 2007 RSV is still running hot.  15 minutes into a ride and its uncomfortable.  The bike otherwise seems to run fine and has plenty of power.

I rode back to the house and with the bike idling, checked the temp in various spots using an IR thermo and the one glaring reading was the exhaust header of cylinder #1 was reading ~400degF, where the other three where in the 175-200degF range.

I pretty quickly get out in front of my skis as a moto mechanic, so hoping someone here might give some advice on where/what to look for that would be causing such a temperature differential on that one exhaust.

Once the bike cools down, I will pull the spark plug to see if there are any clues there.  What should I be looking for?  Running too rich?  Coolant not reaching that cylinder for some reason?

I've had this bike for about a month now and have not been able to ride it for more than 30 minutes at a time (due to the heat coming off it) and I'm longing to get out for an all day cruise on it.

Thank you!

[93 venture]

Wow i cant say what would be causing all that much heat the only time i ever get any heat from mine is in stop and go traffic and the engine fan comes on,  and it has to be real hot out before that even bothers me, yeah i say check your plug for any gas fouled, theses bikes run pretty good on a few dead holes. where are you riding this bike at? ( location)   

[circa1968]

California, SF Bay Area.  Temps in the 90's when I first got it and did a few rides, but 70's-80's now.  

Yeah, I had a '99 years ago and never had this issue.  Thanks, will be pulling the plug after dinner.

[BlueSky]

Due to the heat shields, it's kinda hard to get a good reading on the exhaust pipes of an RSV.  But, 400 is way too high I'm sure.  I check the exhaust pipes on my ZN700 inline four often and they run around 250 to 300 degrees about 5 inches from the head.  A while back I checked them after a 1 1/2 hour ride and all four measured about 265.  

[circa1968]

Yeah, the two front cylinders are harder to get a reading on due to the airboxes, but the back two have about a 1" gap right before it mounts to the exhaust port.  Not too hard to get a reading on those two.  A little trickier in the front, but doable.

If the #1 plug isnt firing, for whatever reason, would this cause the excessive temperature on the exhaust header?   

I did attach a trail tech tach to that plug wire today and getting a tach reading so I know the wire is at least getting electrons to it.  Was going to pull the plug tonight, but getting late enough I'll wait until tomorrow.

[BlueSky]

If it isn't firing the temp will be lower.  The fuel mix is off on that high temp cyl.

[circa1968]

Thanks BlueSky. 

[cowpuc]

May sounds nuts but IMHO,, heat means lean combustion or coolant issue or ignition timing.  Does the physical head/jug on the hot exhaust reading pot read way high? Dont sound like does, sounds like your taking your reading from the header pipes? If so, IMHO, sounds like exhaust temps. That leaves me with the thought that it probably has to do with a lean fuel/air mix condition like Sky mentions because ignition timing issues would probably show up on the other pots as well. Sucking air can cause a lean condition,, a vacuum leak. Have you tried syncing the carbs?  Also, maybe try running an unlit propane torch closely over the carb/intake area while it running and see if you get a change in idle - vacuum sucks in the propane gas which combusts,, make sense?  Pay special attention to the intake manifolds and carb sync caps,, IMHO those  seem to be volnerable.  When you pull the plug check the gap,, seriously wide gapped (should be 32 thou) plug can cause strange things too.. That long arcing has caused overheat for me on my MX bikes at times..  It is also possible for you to have lost fuel metering rod setting on that jug allowing the metering rod to drop lower into the emulsion tube when in turn will lean it out. Those metering rods are how a decent mechanic will fine tune a scoot, at least IMHO.. I would maybe pull the carb slide on that jug and get a peek. Maybe even pull em all if you havent recently, and check diaphram conditions.. 

It would be interesting to see how a sniffer read on that pot compared to the others,,, or at a minimum a Color Tune,, again,, IMHO..

I know,, all sounds like madness BUT,, ya never know till ya try..

Puc 

Edited October 30, 2020 by cowpuc

[circa1968]

Thanks Cowpuc.  I'm reading the temp on the header pipe.  I checked the plug, it is clean and gapped correctly (.9mm)

I spoke w/ a mechanic today and he echoed much of what you said, lean mix, vacuum leak, carb sync or stuck float.  He also mentioned possibility of a stuck exhaust valve.

I like your idea of unlit propane.  At least if I can rule one thing out, its a start. 

I'm ready to throw in the towel and take it to the yama dealer & let their seasoned mechanics fix it.  I was hoping for something obvious and simple, but it rarely goes that way.

The things you are talking about are out of my skill range/knowledge base and I'm getting depressed not being able to ride my new baby. 

I just want it fixed so I can go ride.

[cowpuc]

13 hours ago, circa1968 said:

Thanks Cowpuc.  I'm reading the temp on the header pipe.  I checked the plug, it is clean and gapped correctly (.9mm)

I spoke w/ a mechanic today and he echoed much of what you said, lean mix, vacuum leak, carb sync or stuck float.  He also mentioned possibility of a stuck exhaust valve.

I like your idea of unlit propane.  At least if I can rule one thing out, its a start. 

I'm ready to throw in the towel and take it to the yama dealer & let their seasoned mechanics fix it.  I was hoping for something obvious and simple, but it rarely goes that way.

The things you are talking about are out of my skill range/knowledge base and I'm getting depressed not being able to ride my new baby. 

I just want it fixed so I can go ride.

Again, I remind you, this is coming from the twisted mind of a wannabe mechanic (maybe one of the club's guru's will jump in and help us out here) but IMHO, I dont see a stuck valve creating what you got going on.. The reason why is (try to follow this logic, if you can you have definitely got a heads up on many varmints here who have tried to follow my logic LOL) a stuck valve would cause loss of compression, loss of compression would cause loss of combustion and loss of combustion would cause less heat - not more.. Make sense?  Circ,, when did this begin? Was it after the bike had been in storage for a while?  Another possibility is clogged jetting and storage with improper maintenance is the #1 cause of plugged jetting - especially low speed jetting cause that circuitry is tiny and it dont take much to plug er up - in my limited experience.  Of course, it is also possible that that carb picked up some loose debris in its jetting, it does happen.  One thing to note, fat jetting - or overfueling - generally does not cause excessive heat.  

Here is thought,, a little something else  you could do just to check on.. Do you know where the carb drains are on your bike?  I will post a short vid here that I did for another friend that shows the carb drains, I am not sure if yours are in a similar location as my scoot is a MK1 but this should at least give you an idea. You may want to drain off that carb on the pot that is showing excessive heat.  Open the drain with the key off and let the carb drain into clear jar,, baby food jars work great for this.. Let the drained fuel set for a few minutes and then carefully, without moving the fuel in the jar around, take a pen light and shine it on the bottom of the jar and look carefully.. Do you see debris or even water?  Is the fuel clean? 

Puc

P.S. - you are more than welcome! Thank you for the thank you!! 

 

Edited October 31, 2020 by cowpuc
I forgot to tell Circ he was welcome for the advice! Bad Puc!!!

[BlueSky]

I recommend putting a can of seafoam or gumout with PEA in the gas tank.  And syncing the carbs.  And see what happens.

[circa1968]

You two are gentlemen of the highest order!  Thank you very much.  And big thanks to Don for putting this site together, best $12 I ever spent! 

Just as soon as I'm ready to throw in the towel, you two give me new hope and motivation to keep trying!  BlueSky, I added a can of seafoam to a full tank the other day but haven't put more than 20 miles on since.  How long do you think it would take to work its magic?

The background on the bike is I bought it in Sept from original owner (this is my 2nd time around w/ the RSV, having owned a '99, pre-parenting).  It's a  2007 w/ 21k miles, so obviously a lot of sitting without riding on the bike over the years.  I don't know what the most recent history of how long it sat w/ gas, etc but tank was nearly empty when I purchased it so if there was bad gas in it (likely), there wasn't much, if that matters (I'm guessing not).

Cowpuc, I do follow your logic, so from one twisted mind to another....  😉

A couple other thoughts:

1) Could this recall have any bearing on my heat issue or is it more about oil/coolant possibly mixing? 

2) Is it worthwhile doing another drain/flush of the coolant system?  I previously drained, filled w/ distilled water and ran til hot, let it cool & then drained/refilled w/ 50/50.  I did not pull the fins and drain the cylinder cooling jackets.  Could I have a plug in the system keeping coolant out of that cylinder jacket causing the problem?  You are both leaning towards fuel/combustion issue, which makes sense.  I'm just reaching for straws of what else I could do w/ my limited mechanic skills/knowledge before paying the dealer  - and holding out hope.

Thanks again!!!!!!!

[BlueSky]

Another thing you could try is the shotgun method of cleaning the carb.  If you do a search, you should be able to find the instructions.

[circa1968]

Quick update:

I tried Cowpuc's propane method of looking for a vacuum leak and did not notice any change in idle while doing so.   I also drained the carb on that hot cylinder and did not see any gunk or discoloration.  After a little research on BlueSky's shotgun method suggestion, I did that using straight Seafoam.

I put it all back together and went out for a quick test ride.  Very subjective to my feel & memory, but it ran and accelerated much smoother.  However....that exhaust header on #1 is still running 200 degrees hotter than the others.

I also dumped a full can of SeaFoam into the full tank, in addition to the 1/2 can that was already in there.

I just ordered a set of vacuum gauges to sync the carbs.  They are due tomorrow.

Also ordered a new radiator cap (likely has nothing to do with it, but why not).  When that comes in I'm going to give the coolant drain/flush one more shot, including pulling the cooling fins and draining the cylinder jackets.  Is it possible, or perhaps even a good idea, to try to use some low air pressure applied to the cylinder drain to blow out any possible clogs in the system?

Thanks again for all the advice and encouragement!

[cowpuc]

2 hours ago, circa1968 said:

Quick update:

I tried Cowpuc's propane method of looking for a vacuum leak and did not notice any change in idle while doing so.   I also drained the carb on that hot cylinder and did not see any gunk or discoloration.  After a little research on BlueSky's shotgun method suggestion, I did that using straight Seafoam.

I put it all back together and went out for a quick test ride.  Very subjective to my feel & memory, but it ran and accelerated much smoother.  However....that exhaust header on #1 is still running 200 degrees hotter than the others.

I also dumped a full can of SeaFoam into the full tank, in addition to the 1/2 can that was already in there.

I just ordered a set of vacuum gauges to sync the carbs.  They are due tomorrow.

Also ordered a new radiator cap (likely has nothing to do with it, but why not).  When that comes in I'm going to give the coolant drain/flush one more shot, including pulling the cooling fins and draining the cylinder jackets.  Is it possible, or perhaps even a good idea, to try to use some low air pressure applied to the cylinder drain to blow out any possible clogs in the system?

Thanks again for all the advice and encouragement!

Circ,, please explain your method of checking temp in detail.. TKS, Puc

[circa1968]

Puc,  I'm using an IR thermometer to measure the header pipe as it comes out engine.  There is a ~1" gap between the heat shroud & the engine.  I've attached a few photos showing the two rear exhaust.  Is there a better method?  I've gotten consistently high readings off the 1 cylinder exhaust, tried different angles, distance, etc and still the same results.   I can get to the two front ones as well.  Three cylinders are consistent & #1 is always ~200 deg higher.

[cowpuc]

Geo, are you making the check during riding/stopping to check it or monitoring it during start up/warm up before riding it? NICE lazer temp gun!! Side note, I took my temp gun (similar to yours) with me out to Sturgis back in 2017 when Mom Yam released the new Venture cause I wanted to take some heat tests on the rear pipes/heads while there cause Mom Yam had said she had conquered the heat issues normally associated with Air Cooled bikes (I been into HD's for years and was amazed to hear someone had found a way to mitigate those hot leg issues Big Twin riders had suffered with for years) and I wanted to document what they had come up with.. They absolutely forbid me from "shooting" the new one with my lazer temp gun, they must have heard of the accuracy of those guns cause now I have heard of many new Venture owners are not being happy with what ever method Mom Yam had come up with for heat mitigation.  In the old days it was common to "spit check" our headers to accomplish the testing task,, YOU are definitely on the right track IMHO!! GOOD STUFF!!

[BlueSky]

You should have used carb cleaner during the shotgun method.  It's a lot stronger than seafoam but it should not come into contact with rubber parts.  

Syncing the carbs might help a bunch.  

[circa1968]

Puc, I had been checking after a ride, ~10-20 minutes, enough to get the bike thoroughly warmed up.  Today, for whatever reason, I decided to check it before warmed up.  After about 2 minutes, the #1 exhaust was already @ 400deg.  I think this firmly affirms what you and BlueSky are telling me & trying to get through my thick skull - its running too lean on that cylinder. 

Thanks BlueSky.  I will give that a try today.  I saw a VMax video of someone doing it w/ gumout & getting good results.  All I had on hand was Seafoam, so used that.  I will pick up some gumout, try that.  If still no luck, will then go to carb cleaner.

Sync gauges are due tomorrow. 

Again, my appreciation for the education and encouragement.   You guys are awesome!

[cowpuc]

1 hour ago, circa1968 said:

Puc, I had been checking after a ride, ~10-20 minutes, enough to get the bike thoroughly warmed up.  Today, for whatever reason, I decided to check it before warmed up.  After about 2 minutes, the #1 exhaust was already @ 400deg.  I think this firmly affirms what you and BlueSky are telling me & trying to get through my thick skull - its running too lean on that cylinder. 

Thanks BlueSky.  I will give that a try today.  I saw a VMax video of someone doing it w/ gumout & getting good results.  All I had on hand was Seafoam, so used that.  I will pick up some gumout, try that.  If still no luck, will then go to carb cleaner.

Sync gauges are due tomorrow. 

Again, my appreciation for the education and encouragement.   You guys are awesome!

Circ, unfortunately due to air movement over pipes when riding (front to back) it is entirely possible not get the best readings for diagnoses BUT it might not be a bad idea to look under fuel tank and other air flow areas for blockage of airflow - look for plastic housings that have came loose ect. 

Please do this BEFORE you do the carb sync. With bike cold, 1st start of the day. Maybe grab a pad of paper and jot down some notes. Take temp readings at matching locations on all headers.  Starting with the bike cold, as soon as bike will begin to idle after initial start up  from cold begin taking temps.  Write down length of time idling and temps. Do again as bike warms up without touching throttle.  After bike gets to operating temp so it will take throttle, rev bike while in stationary position two or three times and immediately take temps and continue writing down findings.  Does this show hot header on #1? If so, when did the heat difference begin?

Also,, what octane of fuel do you use? Do you use any fuel additives on a regular basis?  It is possible that you have carbon gathering in the header that is serving as a heat source,, thinking out loud here..  More on that when you answer these questions.  

I am eager for you to receive your sync guages so you can check sync.  What are you getting for gauges?  It will be interesting to see how far out your bike is and what effect, if any simply syncing your carbs will have.  Dont tear anything apart until you get your gauges.. 

Puc

[BlueSky]

The #1 cylinder on my 4 cyl ZN700 exhaust pipe was reading about 100 degrees below the other 3.  I cleaned the carb.  Didn't help.  I synced the carbs.  That cyl was almost closed at idle and it needed syncing really bad.  Didn't help the temp though.  I ohm checked the coils, spark plug wires, and caps and they checked good.  Finally, I changed the spark plug and that fixed it!!!!   Your problem is the opposite since yours is running hotter than the other 3 but I thought I would tell my story just to say, sometimes the last thing you suspect is the culprit.  

[circa1968]

BlueSky, I think I did a cheap version of the sotgun method that just involved squirting some Seafoam down the pilot jet and air jet.  Now I found a better description of what I think you are referring to that involves pulling the slide and mixture screw.  That may be more involved than I'm comfortable with at this point, but desperation has taken me down riskier paths before.

 

[circa1968]

Puc,  I went down the air flow thing as my first attempt to solve the heat issue.  The previous owner put a shiny chrome piece over the radiator.  Took that off away, didn't like the look of it (yes, there can be too much chrome) and didn't see the point of blocking even a little airflow.  I have had the tank, seat, etc off several times and no signs of anything out of place that would restrict airflow. 

Today, I measured the heat diff on #1 within two minutes of a cold start, but I didn't log anything in terms of specific times or temps.  I'm running 87 octane fuel.

I ordered the Alpha Moto guages from Amazon:  https://www.amazon.com/gp/product/B004MSE9JO/ref=ppx_od_dt_b_asin_title_s00?ie=UTF8&psc=1

I decided to soak the float bowl in SeaFoam overnight, clear it out tomorrow morning and be ready (hopefully) for the sync.

To fill the bowl w/ Seafoam, I first drained it then closed the tank petcock and disconnected the fuel line from the tank.  Next, with the drain screw closed, I simply turned the key to ON (didn't start the bike) which triggered the fuel pump to run and refill the bowl with residual gas in the line.  Rinse & repeat until there's no more gasoline in the line, pump or bowl.

Now I used a nice little squirt bottle from the kitchen (hehe, don't tell my wife!) to put straight SeaFoam into the fuel line, turn the key to ON and let the fuel pump fill up the bowl.  

I was pretty damn proud of myself for coming up with that!  You guys are making me dangerous but I'm sure others who are much smarter figured this out long before me.

My plan is to repeat the process tomorrow with a 50/50 mix of seafoam/gas before firing it up.  I've seen some youtube videos of others professing to have had success with this approach.

I'm captiously  optimistic this, along with a sync will bring success.  Or perhaps its just wishful thinking and I'm about to learn a whole lot more about carbs than I ever intended to...

Grateful as always for your input!!

[93 venture]

what about coolant temp, have you used your temp gun to check it. i wonder if the coolant system could have a air pocket causing a hot spot ? the manual says it hold 3.7 qt. Or  possible water pumps isn't moving coolant. even if it had a lean cylinder being a water cooled engine one would think it could take the extra heat  away except what comes off of the header pipe. what did your plugs look like did you take any pictures of them?

 

[BlueSky]

Well now,  I went for a ride on my 07 RSV today and checked the exhaust temps afterwards.  #1 and 2 checked mid-200s.  #3 checked almost 400 and #4 checked less than 200.  So,  syncing the carbs is on my "to do" list now?