My KQ suddenly became hard to start, so I pulled it in the shop and tried to figure out why. I could get it to fire and start and run briefly at full choke, but it would quickly die. Working the choke back and forth would eventually produce the same result, sometimes at full choke and sometimes with no choke. I pulled the spark plug and it was black and sooty on one side of the electrode, and white and chalky on the opposite side. When I grounded the plug and fired it in the wire, the spark looked average but jumped all around the electrode. I replaced the plug, but it didn't correct the idle problem. I pulled the air filter and got it to run, but the idle fluctuates up and down, and it will eventually die if I don't give it some throttle. The foam air filter is very sticky, but the shop that recently worked on it might have put something on it (perhaps to better trap dust?). While it's running, quickly opening the throttle will bog it down, and it sometime will cough through the air box (filter removed) when I do that. If I rev it slowly I can get it to rev up, and it will blow a little black smoke at high revs. I had my carb rebuilt when I got a new top end back in the summer. I can't tell for sure whether it's running out of fuel or flooding. I've removed the fuel line at the tank and get good flow, and opening the drain on the bowl also yields a steady stream of fuel. Any ideas? Thanks.

 

is there any black smoke coming from the exhaust?

 

Yes, but only at high revs.

 

ok i had the same problem on my 97 king...


my was petcock... the weird *** fuel pump / vac system is kinda weird...

i think the part is like $80

 

The guy who rebuilt my top end told me he disconnected and blocked the vacuum to the diaphragm that sits on top of the carburetor because something in that system wasn't working properly. When he did this, he had to turn the petcock to PRI for it to run. When I pull the fuel line off of the petcock and turn it to RES or ON, nothing comes out. When I turn it to PRI, it releases a good stream of fuel. It sure sounds like it's all related. What part has to be replaced, the petcock or the diaphragm? Where did you get it?

Thanks.

 

yup thats the same thing lol


you need to buy the hole new petcock, you can get it at the dealer.

or try ronnies.com


but its faster to go to the dealer cause the price is the same.

good luck

 

Thanks for the reply. Just to confirm, I don't have to do anything with the diaphragm assembly on top of the carb, but simply replace the petcock? That sounds simple enough. Thanks again.

 

yeha just the petcock!


happy i could help!

make sure you watch out for that funky sub tranny!

i would recomend changing the oil every 200 miles!

 

Will do....thanks again.