98 Bayou 220 low compression

[Mech]

Ok. Two thou isn't much wear so a new set of rings, valve grind and seals, and gaskets.. Timing chain maybe ?

You do need to take that lip off though. The new rings will have nice square top edges that will hit that lip and get damaged or will damage the piston. A scraper, sharp scraper, will take the lip off real easy.. It's nice workable metal. Do you have a three sided scraper ?

[DZL1]

Mech, the rings are somewhat springy. I agree that there worn out. 

 

No I do not have a 3 sided scraper. 

But I can get one.

[Gwbarm]

Oh no those measurments are not necessary i just do them out of curiosity. The standard new piston to cylinder cleaarance is around.002 so not far off, not sure of the service limit on your machine. I did notice there are quite a few scratches on the piston on photo #3 they look fairly prominant but it may be the lighting hard to judge. Looking at the last photo the larger valve seems to be riding low in the seat which tells me the sealing surface may be quite worn, it does appear to be sealing good all the way around so maybe not a problem and it may be just Kawaski valve, but the smaller valve looks normal just carboned up. dont see too many of those Bayous, they are good machines, definately worth getting going. I would consider replacing the piston also you usually get a better deal on getting a matching piston and ring set anyway, just part of my OCD i feel like i get a better fit if piston and rings come from the same manufacturer, probaby not. 

[Mech]

The measured clearance sounds like it's too much, but I'm thinking it will because the measurement was taken on the side of the piston rather than front. The pistons are oval and tapered. I think if it really had that much clearance it would have made horrible noises at start up and/or have busted the skirt off by now.

I'm in NZ and parts are dear here, so I generally just replace things if they need replacing, but the economics are different over there and it might well be a better option to buy after market kit with barrel, piston, dudgeon pin, rings, perhaps gaskets. I'd always buy genuine rings if I was doing it.

[DZL1]

Yeah I'm leaning towards getting new piston, rings, valves and new gaskets. But I'm guessing I still need to remove the lip from the cylinder wall? 

[DZL1]

And yes Gwbarm, I do want to get this going because I have another bayou 220 that runs great. And that way when I'm riding and have the wife sitting behind me telling me to slow down, if I get this running, then I can just say I didn't hear her and leave her in the dust 🤣

[DZL1]

Update, so I replaced parts mentioned above and she runs! She just won't idle so I have to mess with carb. It's a new amazon carb that I've used in past and never had issues. I do have an original mikuni carb that I can clean and try. 

[DZL1]

Second update,  I cleaned the mikuni carb, put it on and she runs and idles nice and steady! I rode it nice and slow around my property just to make sure she would actually move and shift properly. Goes into all gears as it should and reverse. But I believe I have to adjust clutch cause she won't actually start moving until I give it more gas than normally. 

 

Will be looking at manual on how to do that next. 

 

Will update as I go. 

 

I want to thank @Mech and @Gwbarm, for all there time and suggestions to help me get this running. 

[Mech]

You can test the clutches to a degree.. You need to have the shift/plate clutch adjusted first. If adjusting it doesn't cure the slow take off problem, put the bike into first gear, and try pushing it forwards..If it feels like the clutch is slipping doing that then it will be the shift/plate clutch slipping. If it tries to turn the engine and doesn't feel like the clutch slips, then the slow take off is probably the centrifugal clutch worn out.

[Gwbarm]

Very good! Glad you got it going.

[DZL1]

Mech, i did whar you suggested and it felt like motor wanted to turn over. So I took it apart and centrifugal clutch has barely any padding material left. And the drum is deeply grooved. I ordered those new parts as well as the clutch disc's. Might as well change those as well since I'm already in there. 

[DZL1]

Update, I have installed new clutch disc's and centrifigul clutch and drum. I haven't tried riding it yet. Question is do I need to adjust the clutch before I ride for first time?

 

Thanks in advance. 

[Mech]

Yes. After fitting it needs adjusting, and then checking a couple of times in the first few hours riding, but I'd make the first recheck after only about five or ten minutes.

I hope you soaked the shoes and plates in oil before installing them ?

Edited February 9, 2025 by Mech

[DZL1]

Hey Mech, thanks for response. I did soak the disc plates and centrifugal clutch, before installing those parts. Ok I'll adjust clutch as you state. 

 

Thanks again!

[Mech]

i may have overstated the ten minute recheck..  I'd use the plate clutch a bit, using my toe on the shift lever to slip it a bit. I'd do that on a ten minute run so I could readjust it before returning it to a customer.. You can probably drive it for an hour or two of regular driving before the plates will have settled in and need readjusting..

[DZL1]

Hey Mech, so I did adjust clutch before first ride, ride it for like 10 mins and re adjusted clutch. Did this before reading your latest response. My question now is should I ride it for an hour or 2 before adjusting again? I ask because it shifts a little harder than normal. Both when up shifting and if I get to 5th gear and come to a stop and down shift to get to neautral, it will shift a little hard. 

[Mech]

The clutch plates settle into place(in the basket grooves) and wear a little of the fluff off, and need adjusting a few times, then they stay in adjustment for so many hours that it can amount to years in some bikes.. 

You can sort of check it by using your toe under or on the shift lever, and seeing where it starts to let the clutch grip, and where it locks up, then checking/comparing that occasionally.

The adjustment.. The book says to turn the adjustment screw clockwise until it becomes hard to turn, then turn it counterclockwise until it becomes hard to turn, then lock the nut there.. But they don't really mean turn it till you can't turn it any more..  haha..  Try it lightly, and then firmly wound counterclockwise, and see if you can feel the action difference using your toe on the shift lever.

 

[DZL1]

I see. Well I can tell you that is exactly what I did. Turn until you can't turn any more. I will try your method and report back. 

 

Thank you. 

[Mech]

It was the "shift a little hard" comment that had me worried.

When you use the shift lever it operates the plate clutch, and I thought you may have adjusted it so that it was trying to push the clutch release bearing too far.. which would make the shift lever not want to move through it's full travel.. 

All good though. It sounds like you've got it sussed.

[DZL1]

Update. So I tried your method and it seems to shift a little smoother. I'm guessing I still have to ride it some more so it can settle in as you stated. I don't even have 20 mins of ride time since repairs. So I will ride it for some time over the weekend and the coming days and see where that leads. 

 

Thanks again for everyone's help. I appreciate it!

[Mech]

You can test the clutch operation.. to make sure it's fully disengaging, and grabbing hard again when you let it out..

If you put it into two wheel drive and heap up a slope in first or second, then while the throttle's still open you push or lift the lever very slightly. It should make the clutch start to slip, and if you let the revs build for a half second or less then let the lever off again, it should be able to spin the wheels.. Doing that tests the clutch and it's what I'd do repeatedly to quickly settle/wear the clutch in.. It's how I check for slipping clutches.. in bikes, quads, trucks and cars..  If the clutch isn't good it'll start to slip momentarily when you dump the clutch. A good clutch will grab fast and sharply.

Edited February 15, 2025 by Mech

[DZL1]

Thanks for that explanation. I will try that.