hopefully people dont hate me for this buuut, after having engine problems with my blaster and finding out it needed rebuilt top to bottom at a cost of between 500-600$ i sold it for 400$ as it was. After that (i stayed in the yamaha family) i got a 78' yz400, its a two stroke dirbike incase neone didnt know, but anyways too the point idk where else to go for this but me and my buddies were out riding and then all of a sudden it goes full throttle and wont go back down, i cant keep it from just going full throttle and the throttle cable doesnt get stuck or anything, you can hear it moving inside the carb from top to bottom, so what else could it be? im thinking its just a carb prob but idk what exactly, thx for any help that can be given =)
1978 yz400
- Thread starter ecurbd02
- Start date
check the carb boot from carb to reed cage/ jugg... chances are its the original one and its dryed out and cracked... if its cracked its sucking air in and wil lcause alean condition/ high rev
you might be jetted improperly. when i first setup my carb for my motor it would rev out real high till i put a bigger main jet in it.
PS what all do you have done to your motor? I have stock everything except my jug is off at FLOTEK getting ported right now. PaulieB also has a 400 but his is a 79 and its all decked out.
also why would we be mad, its not like you stuck a 4 stroke in it. Go check out the mods section
also post pics please of said yz400 swap
PS what all do you have done to your motor? I have stock everything except my jug is off at FLOTEK getting ported right now. PaulieB also has a 400 but his is a 79 and its all decked out.
also why would we be mad, its not like you stuck a 4 stroke in it. Go check out the mods section
also post pics please of said yz400 swap
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now just find a Blaster frame and put that 400 motor in it and you'll have youself one bad ass quad
i havnt done anything to the bike its 100% stock, i know theres no airleak from the boot between the carb and jug, i havnt taken the carb apart yet cuz i just wanna kinda know what ill b lookin for, and ive ridden it 5 or 6 times since i got it, when we first started it up it revved real high and we couldnt get it to stop, but we shut it off and adjusted the throttle cable and it did the trick for a while, then like i said when i was riding it it started doing it again and theres no room for adjustment on the throttle cable nemore, and yea itd b bad a$$ in a blaster frame lol
oh sh*t my bad, i thought it was in a blaster already. yeah look at the cable some more, but look at where it goes into the carb cap, mine also did it the way you were talking about. what your looking at in the carb is for dirt, grime, sh*t that doesnt belong there. also when you pul the bowl off you need to pull the jets out and clean them real good. get some pictures alsoI:I
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