my friend has a two stroke(blaster) and the bike won't rev out. when you give it more than 1/8 throttle, the bike don't run. you can almost hear it sucking for air but gives no power. we have no clue what is going on. he was just riding it one day and it started acting up for no reason. he has a k&n filter and full pipes and it is rejetted. we already did: changed plug, emptied fuel and refilled with fresh fuel, cleaned air filter, and took the carb apart to clean it. i don't know much about two strokes so i don't know what reeds do. i don't know if they can go bad or what. maybe the float is sticking. when he first starts the bike after letting it sit for a day or two it will rev perfectly in neutral. he can usually drive it around for a few minutes just fine and then all of a sudden the bike won't rev at all. you just hit the gas and it almost sounds like its choking and it will die. suggestions would be great. thanks

 

Check for an air leak or a cracked reed.

 

If the blaster is about 5 years old he might need to get the thing bored over about .20 . 2 strokes need to be 'revived' after a little while (4 or 5 years of riding) , but i have never heard of this problem. What he needs to do is call the local yamaha shop and ask the mechanic, it never fails me.if that doesnt work, send in the question to dirtwheels, they always know.

 

trying different solutions to solve your problem is a good idea. If you have done recent mods like a fmf pipe, maybe you put too big of a main jet in, blasters have an oil injection unit that dilutes at like 20 to 1 which is good but very much on the safe side. I had a new blaster in 98 and bought a fmf , k&n ,and boyeson reeds. I thought with all those upgrades id need to go 2 sizes larger on the main jet but i didnt . I ended up going 1 size up but also raised the needle 1 notch, actually i probably couldve just messed with the stock main jet and been fine due to the oil injection. Try messing with the needle location sometimes it is your only problem.

 

where could i be checking for an air leak at? cracked reed, it may be, i honestly have no clue. the bike is only like 6 months old so it better not need rebuilt. as for the main jet, he has a 240 in. i believe 230 is stock and he has full pipes and a k&n. the weird thing is that the bike ran great with that main jet in for a month or so and then all of a sudden it won't rev out. last night we just popped a 250 in for the heck of it. it ran great for 10 minutes and then out of no where we could not give it more than 1/8 throttle. however, i do think the 250 was a little big. i don't see how the needle could becausing the problem since the bike runs good when we first start it but the runs like crap 5 or 10 minutes later. although, it may be that. how do you adjust the needle on this bike? this is a little different than my keihin carb. i guess we could try moving the clip down one(needle up one position). maybe i will check out the reeds. heck, i am a four stroke owner so i don't even know where they are at. are they right inside the intake? he does have an appointment to go to the local shop on monday but he just called me over to see if i could fix it before he had to dish out a couple hundred on labor. any other suggestions

 

just a thought but IS the PARKING BRAKE On? may soudn stupid buy mayb the break swtich thing is on.. not sure when they started puttin them on id check it out... on my warrior the brake wore out needed to be tighted up other wise the brake clip thing would set of the sensor.. mayb thye arent on he blasters!

 

Sounds like the rev limiter is being triggered.

 

when my blaster did that i jus decided to have it rebuilt and bored .40 over. i decided taking chance on trying other stuff might become more costly. but if u still have trouble try puttin new reeds or make sure the gas lines are tight on the carb.

 

Is it fouling plugs? Kind of sounds like a carb problem to me, but I dont know why it would only happen after a few minutes of riding and not all the time. It could be one of the switches, I am not all that familiar with the blaster. Does he have a service manual for it? that could help.

I dont know what switches are on the blasters, but it could be one of those also.

Bat

 

Since we are on the subject my Blaster isnt going as fast as it used to. its a 2003 model and its only about a month old. any one got any ideas why?





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03 raptor
03 blaster (bro's)