Runs great cold - bogs warm

[Les]

I have a '92 Kitty Cat that I just picked up for my son. It runs great and seems to have good power when the engine is cold. Once it is used for 10 minutes or so, it bogs down. I can lift the track, run it wide open to clear it out and then it will run fine again but only for a couple minutes. It idles fine but does not have enough power to get him going. If I push him a little it really won't pick up speed it just slowly chugs along.
Any ideas?
I have not actually bought it yet and I would like to figure out this bogging before I do. I am thinking clutch? The carb is clean and fuel is new with a 50-1 mix.
Thanks
Les

[craig]

I think you should check your engine compression, it sounds like when
its cold it's all good, when it warms up under a load it loose's its gut's.
Check your copression cold when hot you need to be over 100 psi.

[Les]

I checked the compression. Cold it was only at 80 lbs. Warm as lower yet...71lbs. I took the head and cylinder off and it looks like it was leaking at the base gasket and the piston and rings have quite a bit of scoring on the exhaust side it so I will replace the piston, rings and hone the cylinder. So it looks like I found the problem. Is there anything else I should be looking at while it is all apart?
I was also wondering if you know how much to torque down the head bolts.
Thanks for your help!
Les

[Curtis]

I know what your problem is. I have a '72 that does the same thing. The problem is your carbuerator isn't getting fuel fast enough. I know a couple guys who put a vacuum fuel pump and a 18mm Mikuni carb on. That does the trick, but costs like $130. I'm gonna try just putting a fuel pump on and keep the stock carb. If that doesn't work, I'm going to buy the Mikuni carb. Hope it helps.

[Les]

Just thought I would follow up this thread and let everyone know that it is fixed. I replaced the piston and rings (cylinder honed) and all gaskets. Now it runs excellent. Compression is at 110 warm, has lots of power and no more bogging.
Thanks for pointing me in the right direction

[Rev Ronnie]

I think about re-jetting that thing. It scored the piston for a reason, and you have fixed the damage but not the problem. Scoring on the exhaust side is a sign that the engine is running lean. the stock jets are too lean for the cold weather, they need to be changed seasonally if you run it year round.


The Mikuni is the best way to go. here's what it looks like. Ron

http://forums.screamandfly.com/forums/s ... adid=48308

[Les]

I think you may be right as I have been watching the plug and it is not oily or dirty at all. It is light tan. Where would I get a fatter jet? Dealer? What # should I go with? Once my son is older, I might think of changing the carb but for now it's got all the speed that I want him to have.
Thanks
Les

[Rev. Ronnie]

Any dealer thet stocks Mikuni stuff would have them, I think thats the jets I used with the stock carb. I'll go through my stuff and see what I have.

[kiwidad]

Does anyone have a recommendation on where to buy an 18mm Mikuni carb and air cleaner for a '73 Kawasaki ?

[Curtis]

If you are going to do a 18mm Mikuni conversion- e-mail me. I have a tip for you that you do not need to order the carb.
Curt_gagas@hotmail.com
Curtis

[laagerracing]

[quote="kiwidad"]Does anyone have a recommendation on where to buy an 18mm Mikuni carb and air cleaner for a '73 Kawasaki ?[/quote]

If you need an 18mm carb I have them in stock. I also have another carb that works really well on Kawasaki motors.

laagerracing@wiktel.com

[cylinder heads]

[url=http://*/s-cylinder-heads.html]cylinder heads[/url][url=http://*/s-mens-swimwear.html]mens swimwear[/url]