200 has no high end power at cruising speeds

Gotanubike · Post by **Gotanubike** » 04:50 pm Jul 22 2013

I noticed this yesterday when I was going down the back roads on the way to the gravel quarry. When I reach speeds around 60km/h in 4th/5th gear, it cuts out at the powerband(when KIPS kicks in) and I can't get it to go any faster. it revs fine through all lower gears at the quarry and plenty of top end power. Just in the high gears at cruising speeds like suddenly its starving for fuel.

It also over heats and starts pinging so I'm definitely thinking fuel starvation? I'm sitting here with my carb apart right now looking for anything that looks dirty and everything looks ok.

Post by **Julien D** » 05:06 pm Jul 22 2013

What jets have you got in there? How are your reeds?

Gotanubike · Post by **Gotanubike** » 05:11 pm Jul 22 2013

I don't know much about carburetors...they're probably stock though. The reeds aren't terrible but they've definitely seen better days Im sure

Gotanubike · Post by **Gotanubike** » 05:18 pm Jul 22 2013

Maybe you can tell by the colouring??

Gotanubike · Post by **Gotanubike** » 05:31 pm Jul 22 2013

Reeds. Old ones are on the left. I had a new(ish) set ready to install, just hadn;t got around it it yet..The play in the reeds on the old ones aren't too bad though...not even sure the new ones will fit

royadams · Post by **royadams** » 06:06 pm Jul 22 2013

There is a number stamped on the jets

Gotanubike · Post by **Gotanubike** » 06:56 pm Jul 22 2013

158...78 on the pipe one on the inside edge

Postigo · Post by **Postigo** » 07:14 pm Jul 22 2013

Check your float height, it should be 16 mm +\- 1 mm. If your float is to low your carb will loose the ability to supply the gas needed during long or sustained riding.

Gotanubike · Post by **Gotanubike** » 07:32 pm Jul 22 2013

Yeah the manual instructions for that are not so clear. remind me again, the measurement should be taken from the bowl mating surface and where?

edit: oh, 'mating surface to the top of the float'...K then that seems to be to spec.

Postigo · Post by **Postigo** » 07:53 pm Jul 22 2013

Here is how you should set the float. Hope this helps.

Gotanubike · Post by **Gotanubike** » 08:03 pm Jul 22 2013

Right...yes I do recall dropping the floats a considerable amount when I had an over flow issue I couldn't figure out. The overflow stopped so I left it. I'll return it to the original and see what happens

I'm just waiting on a rear tube to come in before i can ride again to test.

Spun the rear tube yesterday then a 10km walk back home with it and found the P.O had it patched. Blew clean through it and almost met the pavement doing 40 around a corner

Actionman · Post by **Actionman** » 01:20 am Jul 23 2013

Make sure you get the right size tube! I know a lot of people say " any 18 inch tube will do" but the previous owner of my bike had 6 rear flats over the course of a few months. The tube he had in it when I bought it (and all his other replacements) were tiny. I sanded down the rim smooth in the inner surface, put on a heavy duty rim strip, sanded sharp edges off any problematic nipples, put down a few layers of heavy duty duct tape- and I still got a flat last week while riding on a smooth flat road! My replacement tube is correctly sized for my tire, and its almost twice the size of the tricycle tubes he had in it. While it may not be a problem, I feel that the correctly sized tube is the way to go.

Actionman · Post by **Actionman** » 01:27 am Jul 23 2013

Gotanubike wrote:Yeah the manual instructions for that are not so clear. remind me again, the measurement should be taken from the bowl mating surface and where?

edit: oh, 'mating surface to the top of the float'...K then that seems to be to spec.

I tilted my carb sideways so that the float tang was barely touching the float pin, then measured with a caliper. Not exactly what the manual recommends, but it seems to have worked great for me. Good luck: once you get that bike jetted right its another world altogether. The Kdx had a really great, strong pull on the top end compared to most of the bikes I've ridden in the past. It's just got plenty of the right kind of power, everywhere you need it. To say I love my kdx is an understatement! It's as close to the perfect bike as I've seen-at least for general fun play riding and trails.ill bet for competition it was an awesome tool for a pro. Thanks to the unelected bureaucrats in the EPA, we'll never see a new Kdx again.

KDXsg · Post by **KDXsg** » 01:32 am Jul 23 2013

could it also be not getting enough spark. Might be a fading stator coil (not lighting coil). My problem sound like yours and after much trouble shooting, found out that the leaking crankshaft oil seal is contaminating my stator and eventually shorted out. No high rev but low end is good.

Post by **Julien D** » 06:57 am Jul 23 2013

There is also the dreaded "Make sure your KIPS valves are working" comment. Just throwing it out there.

Gotanubike · Post by **Gotanubike** » 08:28 am Jul 23 2013

Actionman wrote:Make sure you get the right size tube! I know a lot of people say " any 18 inch tube will do" but the previous owner of my bike had 6 rear flats over the course of a few months. The tube he had in it when I bought it (and all his other replacements) were tiny. I sanded down the rim smooth in the inner surface, put on a heavy duty rim strip, sanded sharp edges off any problematic nipples, put down a few layers of heavy duty duct tape- and I still got a flat last week while riding on a smooth flat road! My replacement tube is correctly sized for my tire, and its almost twice the size of the tricycle tubes he had in it. While it may not be a problem, I feel that the correctly sized tube is the way to go.

They ordered me a tube based on the tire size 100/100-18 and it was $35...It better be the right size!

KDXsg wrote:could it also be not getting enough spark. Might be a fading stator coil (not lighting coil). My problem sound like yours and after much trouble shooting, found out that the leaking crankshaft oil seal is contaminating my stator and eventually shorted out. No high rev but low end is good.

That would be a disaster.

Julien D wrote:There is also the dreaded "Make sure your KIPS valves are working" comment. Just throwing it out there.

Top end was just rebuilt with new left powervalve

Goofaroo · Post by **Goofaroo** » 08:53 am Jul 23 2013

Crank seals are my guess. If that's the case, you'll destroy it if you keep riding it. Do a leak down test and see if the engine is air tight.

Gotanubike · Post by **Gotanubike** » 10:02 am Jul 23 2013

If I had the grabber and puller tools to get the magneto cover off, I'd check but I could see through the two holes through the magneto and looked pretty clean in there...

Goofaroo · Post by **Goofaroo** » 12:34 pm Jul 23 2013

Top end was just rebuilt with new left powervalve

What was it doing before the top end was rebuilt? Are you sure that you aren't leaking air at the reed cage or at the intake boot?

Two strokes are very simple engines but one thing they will NOT tolerate is unmetered air entering the crankcase. Nobody seems to like to hear it but the reality is that these bikes are not getting any younger and the crank seals have certainly got a few years and miles on them. If you do a leakdown test you'll be able to tell if you are wasting your time dealing with the reeds, the carb, the top end, and the ignition.

What year is the bike?

Gotanubike · Post by **Gotanubike** » 12:36 pm Jul 23 2013

E-1.

What do I need for a leak down test?

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