i have a 2002 blassy its totally stock, i have just put a fmf fatty power core full exhaust on it, no jetting the jet is stock at 230 with the mukuni carb.i took it out yesterday it started 1st kick as always about 800yards later bogged out about 30 kicks later still not kickin over whats up!!! please help guys.:-/ i have been on fmf site it says i need 260 main jet will this sort me out?
fmf fatty powwer core 2
- Thread starter yamy_jay
- Start date
you might have seized it. Seeing that ur still running oil injection and didnt swap jets at all i wouldnt doubt thats the case since the pipe created a lean condition.
well ive ordered 260 and 270 main jets they here tomorrow, hopefully it will kick over. its weird becose it bogged out, i left it about 2 hours kicked it over it, it sounded like it was gonna start theres stacks of compressing so surely not seized? im not mechanically minded but if theres compression there fuels fine it must be the jetting?
i should have said the piston is scored instead of seized. I have had it happen to me, you might be able to keep it going if its not too bad. Have a shop hone out the cylinder and make sure the rings arent stuck then reassemble the engine.
right im checking it tomorrow, ill change the jet and new plug kick it, if no luck ill check the reeds or ill pull the head off check the piston and rings and go from there. wish me luck haha!!!
ive just cleaned the carb, 260 jet and new plug. still nufin!!! but good news at last theres no damage to my piston or rings the barrel is perfect, my reeds have snapped haha how could my new exhaust do this or is it just a coincedence well im happy new reeds and its running 
I put the FMF setup on mine after having it (bought new in 2005) for a short time. I had bog issues and had to rejet. But it still ran...just not real good on the top end and under load.
Never experienced failure. IMO the reed just was wore out and that did it in.
I bought a 260, 270 and 280 jets. I tried 280 first. I ended up with the 270 in. I still have an unopened Yamaha 260 jet I didnt even have to try or use.
Id say 260-270 is right on.
I dont recall why the 280 didnt workout, but from my automotive carb tuning experiences, Im sure it was something obvious in the way it ran.
All this was done at the time of N Fla humid/hot summertime climates.
Hope this helps
Never experienced failure. IMO the reed just was wore out and that did it in.
I bought a 260, 270 and 280 jets. I tried 280 first. I ended up with the 270 in. I still have an unopened Yamaha 260 jet I didnt even have to try or use.
Id say 260-270 is right on.
I dont recall why the 280 didnt workout, but from my automotive carb tuning experiences, Im sure it was something obvious in the way it ran.
All this was done at the time of N Fla humid/hot summertime climates.
Hope this helps
cheers lads, its sorted now i have put needs reeds in, its running perfect again the fmf set up and 260 makes hell of a difference. what other mods can be done without losing reliability? i need my rear brake upgraded cable brakes suck ive cleaned em about 10 times they work for about 5 hours of use them there useless! who are the best people for this if i cant get the later model setups shipped out to the uk? uk ebay sucks no1 got blassys!!
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