Jump to content

Kx85 bogging

Recommended Posts

So today I had a race and practice and heat 1 went very well. After about my 2nd lap of heat 2 my started to bog down. I would try to give it full throttle it would bog down so I would kind of be choppy and then once on the power band it wasn't as boggy

Share this post


Link to post
Share on other sites
On 6/18/2017 at 7:13 PM, Bidulez said:

Did you try a new plug ?

 

 

On 6/19/2017 at 7:24 AM, numroe said:

Warm weather?
Clogged air filter?
Guncked up power valve?

Do you think it could be because I had it idling at the starting gate instead of revving it?

Share this post


Link to post
Share on other sites
1 hour ago, Damien_Kawasaki said:
Do you think it could be because I had it idling at the starting gate instead of revving it?

No. A mechanically healthy kx85 which is tuned correctly will cope with idling or low RPM use for as long as you wish.

Revving at the start is to clear out the case and get the cylinder and coolant temp up. For max power when you go.

Try a new plug and freshly oiled clean air filter. If the motor still runs a bit rough and you're confident your piston+rings are not worn out, and your muffler is clean inside, then you should try leaner jetting in your carb.

Which adjustments to do in the carb depends on at which throttle position you think the motor feels the most rich.

Below 1/4 throttle = pilot jet (go one size smaller)
Around 1/2 throttle = needle clip (lower the needle = clip higher)
Wide open = main jet (go one size smaller)

Maybe you choose to do a couple of adjustments at the same time. Your choice.

Ignore RPMs. Focus on feeling the motor at constant throttle. Pick a suitable fixed gear. Find a long uphill straight if you can, and hold constant throttle (1/4, then 1/2, then wide open for each run), then feel the motor's power as it pulls through a wide RPM range.

Rich or lean can cause a motor "bog".  Rich and lean cause different problems..

Rich does this:  Rough running, misfiring, blubbery, weak power, smokey, wont rev out.

Edited by numroe

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:


×