I got 351/34mm pump carb..... 65mpg road, 34mpg on the trail. If you are riding hard, you are using gas.

 

I know others have knocked it, but if the diaphragm is difficult to get into the groove, soak it in HOT water for a while first, wipe off the water, and put it in right away. It will also help if you can get a finger into the carb to lift the slider while fitting the diaphragm.

 

I've found if you let them sit on the bench for a few hours they shrink back to original size.

Thank ethanol in gas for a lot of this problem. Back in the '90's I did more jet kits than I can count and almost never fought this problem. Replaced a fuel line on one of my chainsaws last week. It was so softened I think it was collapsing instead of drawing fuel. After is sat on the bench overnight it firmed up like a new hose. Switched my 2stroke mix to 100LL (no ethanol, very stable) since my saws sit a lot.


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I pulled the carb lid tonight and redid the slide to make sure the seal was good. Reinstalled it and now the bike fires up and runs even when I twist the throttle wide open. I took it for a very short spin, and now the bike runs great up to about 6,000 RPMs and then zero power after that and it pretty much doesn't matter what gear I am in. I think first willgo up to about 8k and then no more. Suggestions?

 

Are other people having major problems due to ethanol? I had a Ducati Sport 1000, and while United States fuel destroyed the Acerbis fuel tanks Ducati used in large scale, there was never any difficulty with the rubber parts in the fuel system. If there was exceptionally cheap fuel used, that may hurt it but there would be a lot of problems with other bikes. If you think you've lost the vaccume valve, it may be from the modification. I still suggest you return the bike to stock and start the modifications over. Do you need to drill the slide to add the silencer? Should only need jetting and a slight adjustment on the needle for a stock motor.

 

Nope. Personally i think its just ****ty grade fuel we are getting and not the ethanol that is causing 90% of the problems.

 

Couldn't agree more. The only blessing here is Kawasaki makes a pretty tough bike. I hope fixing the slide is the answer and seems to make sense at this point.

 

HELLO! Very interesting numbers considering this issue.

 

Simple one. Pull your air box lid, or snorkel, or change to stock snorkel. These are easy changes and may help narrow it down. I normally run with the lid off. This summer I tried with lid on, snorkel out, and snorkel in. The bike did okay on the lower end, but wouldn't pass around 8K rpm and just ran out of power up there. Real rich.

Do you have a fuel filter installed?

 

What he said. But also, check again for vacuum leaks.

I normally run my bike with the airbox lid on, but with no snorkle - and it runs quite well that way. Without changing jetting, I tried installing the stock snorkle - lost significant power, much slower to rev, lost top speed. I also tried removing the airbox lid entirely - the bike became unrideable, would not rev much over the middle RPMs, and lean-surged SEVERELY under load at highway speeds.