KZ440 bogs on hard acceleration and full throttle

I love that word pal. It's so derogatory and implicates the original intent.I'm sorry I'm so cynical these days. Sorry I'll likely leave shortly t oo. Don't need much help these days. Prefer just a bit of camaraderie but this is littered with subterfuge and that I can't handle.

Dont no much about the two cylinder bikes but I would think it has something to do with the one soot covered plug . That one is definitely running rich . I would check that carb .

Have you checked the valve adjustments .

I read that the old left plug was sooty. Have you checked the condition of the new plugs to see if one is sooty? That might help narrow down the problem to one carb or cylinder. Ed

The sooty plug may also be the result of a bad Val e atem seal and not related to the bog. The rattling in one of the pipes could easily be some badly rusted chunks of baffle that are restricting exhaust flow at higher rpms.

riturbo wrote: Dont no much about the two cylinder bikes but I would think it has something to do with the one soot covered plug . That one is definitely running rich . I would check that carb .

Have you checked the valve adjustments .

I've checked the carb pretty thoroughly, and I've also done the valve adjustments. I guess it could be sooty if the left side exhaust is restrictive...

I've checked the new plugs first and they are the same condition as the old ones, left side sooty, right side seems fine.

Not wanting to just chop off the exhaust until I had a replacement in hand, I drilled three 1/2" holes in both mufflers just after the header pipes so air could get out. I had started with one per side and noticed the bike seemed better so then I added two more. on each side.

Now the bike seems a lot better! Way peppier! I don't really have anything to compare it to because this is my first bike, so I just thought that was it as far as performance went.

It still bogs down sometimes at WOT, but at higher revs and not all the time anymore. So it's definitely all or at least mostly exhaust related. But at least now I can ride it and bomb around town happily.

I ordered some of those EMGO slip on reverse cone mufflers from amazon and I should have them installed by tomorrow (fingers crossed). I will let you guys know how it goes. a pet peeve of mine is these threads where the OP doesn't come back to say if they fixed the problem or not!

Do I chop the original exhaust before the crossover pipe or after?

Some pics of your exhaust enviromevd or the collector Body???

Sure, first pic is the bike now with original exhaust, second pic is the emgo reverse cone exhaust, it is 17" end to end.

Well I put the new exhaust on but it didn't solve my problem. The engine just seems to get "stuck" at a certain rpm, and when I twist the throttle it changes the sound but the rpms stay the same. Sometimes it sticks for a while, sometimes it's just for a second. Sometimes I gear up and it stays stuck and other times not.

Tomorrow I will check to see if the sliders in the carbs are sticking. I am now officially out of ideas.

Yesterday I made sure the carb sliders were moving nicely in the carbs and readjusted the pilot screw and made sure carbs were synced again.

Today I did a compression test (170 and 175) and since that checked out but one plug was still sooty I thought maybe it was the valve seals so I replaced those.

I still have the same problem with acceleration, it's just not as bad. Now it can more easily get past the bog down spot. And sometimes the big down doesn't happen. I can pretty much make it happen every time at WOT in third gear at high RPMs though. But now it seems to be faster and doesn't stick as much.

I went for a ride, came back after 20 mins and put a new plug in the bad cylinder. Went for another ride and the new plug is sooty!

If compression is good and valve seals are new, It can't be oil can it? Maybe it is rich? How do you end up with rich in one cylinder?

Have you checked the float height on the carbs ? Search clear tube method on here .

This might help with your tuning www.factorypro.com/tech/tech_tuning_proc...igh_rpm_engines.html