hello, im new too this so bare with me. i have a 1997 yamaha blaster thats stroked 4mm, FMF pipe, vito's degree key, DP clutch kit, wiseco piston bored 60 over, the engine doesnt even have 10 hrs on it and was running perfect untill my kick start spring fell down inside my engine we got the spring out with out having any damage done to the engine, after it was put back together i cleaned the carburetor and put everthing back together and went to start it thats when my problem occured. every time i kick it, it back fires and if i hold the throttle about half way it will start but doesnt seem too want too open up and if you let compelety off the throttle it dies. i have changed the plug, checked the reeds, inspected the cylinder and piston, and cleaned the air filter, so now everything is down too the carburetor. im running a vito's 300 main jet and when i pull my spark plug out it is wet and when i can get it running it smells really rich. but what gets me is it ran perfect before all this happened. any suggestions on what i should do would be greatly appreciated since im kinda stumped. Thanks -Dan

 

clean the carberator, what size carberator, might need to lower the jet

 

i have cleaned the carburetor, its the stock carb with a vito's 300 main jet. i was running a 270 jet, i was wondering about putting that back in too see how it ran on that. if i put that 270 jet back in how are some good ways to know weither its running lean or not, reason i jumped too the 300 jet is cause it was starving for fuel on top end with the 270 jet, it ran fine for about a month on the 300 jet untill now. i know the 270 jet is bigger then a stock jet on a blaster carb, i just wanna make sure i dont run it too lean because the guy that did my case machining and head machining said with as much compression it has running the engine too lean would burn a hole in my piston pretty quick. thanks for the info you gave me and any other info would be great i really dont know where too go next on fixing this.

 

It will probably need some extra fuel over stock displacement. Did you readjust the idle mixture. That might be too rich and that's why you have to part throttle it on start up. As for your starving for fuel on the top end problem, I'd try adjusting the float level in the carb and see if that helps. Was it lean with the 270 or just cutting out on the top end?

 

ya like i said the blaster was running perfect for about a month with the 300 jet, untill i had the kickstarter problem, when i had stuff apart 2 fix it i cleaned the carb. once i got it all back together i went 2 start it and i got the back firing problem while trying 2 start it. then once i held the throttle half way it would start but run really bad. so i pulled the plug and it was soaked. im wondering if when i put the jet in maybe it was clogged or something and when i cleaned it, it now letting 2 much fuel in there. tonite im taken it up too a friends house too try and find the problem change the jet and mess with stuff see what happens any other info would be great or if u need too know something else let me know really gotta get it fixed because i want too ride bad lol.. thanks for everything

 

I thank everyone that has tryed 2 help me on this.. i worked on it tonite ended up that my vito's degree key snapped or sheared in half when my kick starter spring fell off this must have happened. getting a new degree key friday and will be riding it again. again i thank you that have tryed too help, keep in touch. later -Dan