Bayou 220 Rebuild Overheating

[stevetro]

Hey,

I'm trying to get my '96 Bayou 220 recent rebuild project up and running properly and now I just can't cure an overheating problem.

What do you think would cause this engine to overheat the fastest and actually get the header pipe glowing red inside of 10 minutes. Could it be an overly lean condition, or lack of lubrication - what could bring about this overheating faster?

You can see the long story on this bike at this thread:
http://www.kawasakimotorcycle.org/fo...r-rebuild.html

Right now all I'm troubleshooting is a lean condition:
- Boots/insulator/o-rings are new and tight on both sides of the carburetor
- Carb/pilot circuit all clean and clear
- I've worked the air/fuel screw from 1.5 to 2.5 turns with no noticeable improvement or change.
- Plug is whiteish as if it's lean.

Engine idles fine, but will pop and stutter every now and then. Also pops and backfires slightly with short revs of the throttle.

I'm also under the impression that the carb float level is correct from the measuring I've done.

I'm just stumped which condition could bring about the overheating fastest. I'm now starting to lean towards a lubrication issue, but I wouldn't think that would cause the stuttering and back firing? Man I'm confused!

Keep in mind that all this tersting is being done with the bike standing still, I've yet to ride it for fear of blowing it up.

Please help!

[RCW]

If you are working the pilot screw at the bottom of the carburetor, just ahead of the float bowl, and not getting any discernible change in idle between 1.5 to 2.5 turns, the problem is the carburetor.

If the engine is running over 1,800 rpm then the pilot adjustment will not do a thing. So, start with the proper idle adjustment first, then determine where the lean condition comes from. A broken c-clip on the main jet needle can be hidden by too rich an idle from a miss-adjusted pilot circuit, and then the main circuit does not feed enough fuel over 1,800 rpm and can lead to a very lean condition.

I would totally disassemble the carburetor and put it back together as outlined in the manual, or use the parts diagrams to identify the location of each part.

Just how much air are you blowing over the engine as it is running stationary for more than two minutes? If you are not moving enough air it will overheat seriously.

[86klf300guy]

id be leaning towards your running lean or have a major restriction in the muffler.

try slippin the muffler off and fireing it up and see if it stops turnin red and stop the popin noise.if so restricted muffler

but if not ten you might want to check the main jet needle and its cir clip position.that needle has 5 rings on it move the cir clip to the middle ring and see if that helps with the muffler back on if its not restricted.if it make an improvement but still not quite right move the needle down one to further richin the ffuel mix-

hope this may help you out -corks-

[stevetro]

Thanks guys.

I'm now kinda thinking lean as well since after I start it with the choke then back off and reach a fairly stable idle, it starts the symptoms right away. This is before the engine gets real hot, so that could rule out a lubrication issue.

To RCW - I actually was not blowing any air so I better devise something and get right on it.

A little background: the carb has been gone through a few times, is very clean, and was rebuilt using an after market kit. I did this mainly to get a new float needle and gasket at a good price. I did notice that the pilot and main jet matched numbers to original, but to the naked eye I can see that the holes appeared smaller (leaner) than original, so I put back the originals. This was before any testing. I found this kinda strange. I'm real sure everything is together OK, but I'll triple-check. Fuel/Air needle is intact and matches original to a tee.

I've also blown carb cleaner through everything and it is clear and clean, that's why this is so frustrating.

Another question, what would be the best way for me to have the carb soaked or boiled-out? When I was in the local dealer recently, I noticed Yamalube had a carb soaking solution for like $12 - anyone use this stuff before? Or should I just have the local shop do their thing (which I hope is not just this stuff anyway)? I just want to be sure some part of the circuit is not clogged and I'm not noticing it.

86klf300guy - I'll also try the muffler test. BTW, circlip and needle are also new and set to default middle position.

Thanks in advance guys - keep the advice coming, greatly appreciate it!!

[86klf300guy]

i take my carb to a machine shop and have it boiled but you have to take eveything out and off the carb includeing the butterfly if equiped.or just use seafoam on a 1 or 2 day soak and compressed air and listen for air to blow through the carb and its circuits.-corey- move the needle clip and see what happens also make sure your jets are in the correct spot ,they fit in eachother locations the bigger holed jet is the main jet ,a that screw in to the adapter thing that screws into the carb.

[stevetro]

I'm going to try and get the carb cleaned out professionally even though it appears spotless to me - but of course you can't see the inside cavities.

Let me throw this out there as well; after my head and jug was bead-blasted on the outside to clean up the finish, I went and painted it with high temp paint with all covers and bolts installed - absolutely no inside cavity or orifice was hit with paint.

I wonder if this outside surface alteration could affect the self-cooling properties of the air-cooled fin design?

I might be clutching at straws since I've seen plenty of engine rebuilds completed with a nice new coat of engine paint.

[86klf300guy]

naw heat paint wouldnt do nothing to it but make it look perrty lol.
my fins get caked in mud and mud is a insulater of heat and my pipe never turn red and itll idle for 30 - 40 minutes at a time (to get un stuck from the hole i got my self into lol.).have you tried tyo readjust the carb by turnin the screw out on the air flow and messin with the circlip.?-corey-

[wayno]

Check the ignition timing,this will cause a glowing exhaust no problems.Wayno1500 drifter

[86klf300guy]

Originally Posted by wayno

Check the ignition timing,this will cause a glowing exhaust no problems.Wayno1500 drifter

if the timin was to far advanced like a couple teeth on the cam i can see that happening. but i can also see a vavle bending in the process do to low valve to piston clearence.?

might even be the float hieght is set to tight to the boby of the carb (not hanging low enough in the bowl)or a bad or swelled float needle causein lack of fuel to get to the bowl?or bad fuel supply to the carb?to many variables for a lean condition even the wrong heat range plug can cause a header pipe to glow red.

its starveing for nice cool fuel some where some how id play with the carb float and needle jet and air screw,-corey-

[stevetro]

LOOKS LIKE I NAILED IT!

I broke down the carb and soaked it in a gallon of Gunk carb cleaning solution (the strong stuff) for 2 hours. Cleaned and reassembled it, then set the needle clip down 1 notch from center and set the fuel/air screw at 2 turns out for starters. It started right up and was not lean at all, not backfiring, etc.

Took her for a run and no overheating. Then I decided to reset the baseline to see what the problem actually was, so I put the needle clip back to nthe middle and set the fuel screw to 1.5 turns out, and again it ran fine. So I can only say now that what appeared to be a pristine carb, just may have had some inner channel clogged up. Either that, or the fact that I removed and reset the engine side intake boot to ensure no leaks. I'll fine tune the mixture as soon as I can locate a nice tiny screw driver that will allow me to adjust the screw without rotating the carb.

Either way, now it looks like I can continue investing into the restoration since the engine rebuild appears good to go. Now for the easy stuff!

Thanks again guys for all your help ansd responses. -Steve

[86klf300guy]

cool i knew you get it ,a good carb soakin or dip can remedy alot of bullshucks when a lean or rich condition presents its self as your did .happy rideing and be safe -corey-