float level mimic lean bog???

[gator kdx]

I have a 90kdx200 with stock 35mm carb, airbox mod, pc platinum pipe, pc 304 silencer, and boyesen reeds. My jetting is 150 main, 45 pilot, 1172 in mid position and AS 1 turn out. My float level has been a problem for a while - i actually stopped riding this bike for a while because of it. Previously I made a float gauge out of a clear tube and attached it to the carb so I could verify the float level when on the bike. Despite all my efforts and adjustments the bike would always pee like crazy (unless WOT).

I love the top end response of the bike, from open 1/2 throttle on (I guess about when the exhaust valves open) the bike sounds great and is really snappy. However, the bottom 1/2 of the throttle is really boggy and sounds strange. I've read every post and article I could find about jetting and it seems like I'm experiencing a lean bog. I'm a jetting novice though and can't tell from the sound. Is it possible for the high fuel level to be causing my bog (Also, when it bogs there is a more than normal amount of smoke)?

 

[BucKat]

Read up at Canadian Dave's Website
http://justkdx.dirtrider.net/
He's has all the jetting info you'll need and how to properly set/check you float level...

Good luck


Buc

 

[gator kdx]

The float level has been a nightmare. I've tried settings ranging from 14-18mm hoping to find a good location. No matter how high I set the height though the carb keeps dripping. I've replaced the needle 2x and cleaned the needle seat thoroughly. The float is well used but is not waterlogged or misshapen. I've got another float on order and hopefully somehow that will resolve the problem. If not I guess I will give up on this carb and maybe see if i can find an airstriker or some other replacement.

I'm still unsure about my original question though, is it possible for a too high float level (resulting in carb peeing) to produce a low bog?

I would have assumed that the excessive fuel would increase the pressure in the bowl forcing more fuel through the jet richening the mixture.

Thanks in advance for any suggestions or advice

 

[BucKat]

Originally posted by gator kdx

I'm still unsure about my original question though, is it possible for a too high float level (resulting in carb peeing) to produce a low bog?

Yes,,,it is possible.A rich condition in any of the carb circuits will result in a bog..
But there are too many other variables to say for sure that this was the absolute problem.

How did the bike run prior to the excessive fuel.?
Do you have dirt in the tank or in the bottom of the carb bowl?
Is your filter in the fuel tap-assembly?



Try this..
Turn fuel off...take carb bowl off and hold floats up to close needle and seat ....turn gas on and see where/how the fuel is passing into the bowl...( no smoking at this point :flame: ).
or......try this safer approach

turn fuel off...remove fuel line from carb....install new/clean hose on carb,,,,take off carb bowl and hold floats up to close needle and seat....blow into new/clean hose to see/hear if any air is passing through the needle seat unit...


Let us know.

Buc

 

[gator kdx]

Thanks for the ideas, i'll try them as soon as I get off work this afternoon.

As far as the float level issues, since I got the bike last year the float level has been out of whack. So I really don't know what the bike is capable of. I've got 4 new needles from Sudco and a couple of extra jets sitting here just waiting for me to get the float issue fixed. I can't wait to ride it when its properly jetted.

 

[Wolf]

This is probably no help to you as I assume you checked already...
I experienced the same symptoms and attributed it to the float level, BUT it turned out to be dirt in the tank.

 

[gator kdx]

I did check the gas tank about 2 months ago and it was fine then, but I probably should check it again. Who knows, maybe I missed something before. And in answer to an earlier question, the filter is in the fuel tap assembly.

Wolf, when your tank was dirty did that result in an overflowing carb - or the appearance of float level set to high --excessive peeing? I would have thought that typically a dirty fuel filter/tank would slow the fuel flow causing a lean condition?

 

[Wolf]

The problem I had sounds similar to yours. Bike would "pee" at times, then it wouldn't. The hole thing drove me crazy. It would run great one minute, then it would just run crappy. I still can't believe that I never checked the tank first.
I checked my float level 3 times, and I had someone else check it too.Then I decided...its got to be something different....On my last ride, the bike was peeing again...I tapped the carb with a wrench a few times, but it did not help. I took the bike for a little spin and crashed hard....that fixed it:) Upon teardown, the filter in the petcock showed a nice tear in it, so dirt could flow "freely". My guess would be that at times dirt got stuck and screwed with the needle jet, so it could not seat properly.
I cleaned the tank, replaced the fuel valve assembly (mine was beyond repair) and now....no more pee....no more dirt in the carb.

 

[JasonWho]

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[BucKat]

Just a thought...
You stated that you've set your float level with a homemade float gauge..Did fuel continue to pass while setting the level??
If so,,,,how could you ever set the level correctly..?? Just a question.. ;)

Is it possible that the floats are bent/twisted such that they are binding when the float bowl is installed??

How have you made out so far??



Buc

 

[gator kdx]

I've tried my homemade float gauge in addition to trying the methods mentioned on the justkdx website - parallel and caliper measurement. I used my homemade gauge just so I could see where the fuel level was when the float closed the valve (with the bowl on in case I was getting some weird float action like you mentioned that only happened when the carb was put together and on the bike).

So far I haven't found the problem, but I got my new float in yesterday and am going to put it in this weekend and give the whole carb a good cleaning and inspection again.

Thanks for all the input.

 

[BucKat]

Let us know what you find.

Buc