4 Stroke running HOT!??

[RyanRX7]

well I've messed with it and still no go. On this carb you can't adjust the needle, and it's not running lean because the condition still happens even if the choke is on. The pipe heats up within the first 3 seconds of it running, idle or not. Almost as soon as you start it, it's glowing. even before the engine gets hot. Any ideas???? I was thinking exhaust valve not sealing and allowing combustion into the exhaust. Runs good other then that, starts right up. The guy who owned it before me put like 2 quarts too much oil in it also. Thanks again

[bigredhead]

Easy enough to do.. have you re-adjusted the valves lately ?.. specially the exhause valve ?

what shape is your pipe in ? both bolts on the head ? any snapped ? check the pipe carefully for leaks ...

Does it idle high ? or normal ?

[RyanRX7]

I would say it idles normal, and I replaced the exhasut gasket thinking it was that. Havn't adjusted the valves though, do you think a simple valve adjustment could cause this??? Thought it would just run like crap. Thought it was a lean condition for a long time, but that plug is gettin black from me richening it up so much.

[bigredhead]

is it an original headpipe ? or aftermarket ?

[RyanRX7]

original headpipe

[Wickedfinger]

First off - what kind of machine are we talking about?. Its definitely a too lean condition, without a doubt, especially with the white plug check. I'm assuming its a thumper because I've never seen a 2-stroke that could run long enough that lean as to "light up" an expansion chamber. Secondly - if you didn't do anything at all in the way of intake or exhaust modifications - even an air filter change - then I would suspect some sort of mechanical break down that is letting too much air into your fuel charge, messing up the ratio. However, you didn't say if the machine was idling irratically (a sure sign of an intake tract leak -or - a bad head gasket). An exhaust leak would only possibly effect a 2-stroke (it just makes a 4-stroke louder - unless the leak is right at the cylinder head and huge, then definitely) and it would have to effect a 2-stroke in a way that it could negatively change the way the pipe sonically draws the charge and creates some sort of lean condition. But again, I'm assuming your ride is a thumper. Air temp and humidity do not tend to effect 4-strokes even remotely as much as it does 2-strokes, however, altitude does - but - unless you dropped in altitude, it wouldn't lean it out. Some sort of wacky fuel mix up could do it too I suspect - especially if you put some sort of "fuel de-icer" or water remover containing alcohol in it in an out or perportion way. I guess I need more information - especially since you said theres no needle adjustment - but I am heavily leaning twords an air leak somewhere.

[RyanRX7]

Doesn't idle funny, used to only idle with the choke on, but I've worked that out. It is a 4 stroke per the post title. The plug reading was whit that one time, I've since richened it up amd even tried running with the choke on and no matter what the pipe will heat up from dead cold to glowing in 5 seconds as soon as you start it up, and without reving the engine. The carb is of the vaccume variety where the slide and needle are attached to a diaphram that causes it to move up and down. I've cleaned the carb out very well and tried it with and without the air filter to see if there was a change, still glows. Runs pretty good, might have a slight valve tap but that's all. The plug was getting black last I looked.

[bigredhead]

what bike is it ? model make year.

[RyanRX7]

It's my 86 Kawasaki KLF300 that's giving me the trouble, I know it's not a trike but I needed some generic help and the quad section doesn't get much trafffic.

[Wickedfinger]

My bad on the missed title.

The carb is of the vaccume variety where the slide and needle are attached to a diaphram that causes it to move up and down.

That may be the case, but there is still a jet needle in there with a clip. You have a slow/pilot jet and screw and a regular mainjet in the #130 range. There seems to be alot of funky "vacuum" type hoses on that engine - I'm wondering if you have a leak in one?. What I would do is re-zero everthing back to factory spec - i.e. get that pilot screw back to 1 1/4 turns, button up the airfilter and run it. I would then check for an intake leak first by spraying some (a little) starter fluid or WD-40 around the carb, intake boot and head and see if the engine starts to race or even rev a little. If it does, correct the issue and problem probably solved. If it dosent - I would then start to play with your jetting - the only thing is, these issues don't just start happening by themselves - unless: 1) again you modified the exhaust or intake in some way, 2) the machine has always done this since you've owned it, then it might have been "messed" with in regards to jetting, or 3) the chamber has developed an excessive amount of carbon build up and it has raised your compression ratio to a point that lower octane gas is leaning things out due to detonation or 4) something has failed of moved out of spec. mechanically.

[Wickedfinger]

I also forgot to mention that it very well could be a timing issue - however - in trouble-shooting, you always go fuel first, then electrics.