break in disaster

[98blaster+4]

okay so i finally get to start my blasty after the top end rebuild
it starts kinda hard first time and wont idle without a finger on the gas a bit
let it idle for 15 minutes just like the guide says
cool down and idle again and cool down
then i go to ride it for the first break in ride runs like absolute dogshit
pull the plug out and put in a different one starts up easy now but wont go anywheres ,and i cant rev it up,its like it has no power ive gone through 3 plugs now and dont have anymore. when i do get it to move on its own it wont go worth a darn i can shift up and down but its got no power,
does antbody know whats going on ,also i havent changed the carburator from the way it was before the rebuild ,mostly cause it is confusing as hell
can anybody field this one?????

 

[kylepotatoes]

Have you cleaned the carb and removed the TORS?

 

[98blaster+4]

tors is disco'd
what should i check on the carb

 

[kylepotatoes]

Make sure the jets aren't clogged, maybe let it soak for a day or something and make sure it's jetted right for your setup.

 

[98blaster+4]

the only thing thats changed was a +4 overbore to a +1 overbore so the jetting should stay the same right?

 

[hartle02blaster]

if it was running right before the rebuild then i dont think its the carb id check the compression maybe the head gasket also but anyways let me know if it seems to have good compression and ill let ya know from there cause i have rebuilt these a few times and alot of other 2 strokes

 

[Justinlhc]

How long did it sit for? Are you sure the rings lined up right? Did you use all new gaskets?

 

[98blaster+4]

its got a brand new gaskets top and bottom of cylinder and still has plenty of compression
the ring s were sitting in the grooves with the spaces where they were supposed to be

 

[89custom]

thats strange, only thing i could think of is jetting. how are the plugs? you said you keep replacing them, but are they black and wet? if so your jettings to rich.

 

[98blaster+4]

the plugs are just as you say black and wet
would downsizing the cylinder bore cause it to run richer than before?

 

[Justinlhc]

the plugs are just as you say black and wet
would downsizing the cylinder bore cause it to run richer than before?

I would say so. It's not able to suck as much air with a smaller piston, but your jets are still giving it the same amount of fuel.

 

[98blaster+4]

is there any adjustments i can make to compensate for the rich mixture without a new jet?
the reason i ask is its sunday and yamaha isnt open here in my neck of the woods

 

[89custom]

downsizing, defently. did you get a new cylinder or something? i didnt quite understand your first post. whats your main jet right now?

 

[98blaster+4]

see thats the part i dont know
i cant seem to get the carb all the way off because of those stupid oiler lines
can the jet be rmoved with carb still in bike??
and i bought a different cylinder and i believe its only been bored once
the top of the piston said .050 on top

 

[89custom]

if you take it out of the airbox boot and intake boot so you can turn it so the bottom can face out, you can take that nut in the bottom off and then the main jet is right in the middle. then use a 8mm socket i belive to get the main out then put the new one in. the jet numberso n the bottom of the jet or the side. pull it out to check.

 

[98blaster+4]

now ive heard that removing the airbox lid can give you more poweris this true?
could i simply take it off to compensate for the amount of fuel being pumped in?

 

[djack12]

alot of members remove the air box lid or dtill holes in it. the stock is really restrictive. i think you would be fine.

 

[98blaster+4]

so i should ditch the cover and leave the jet alone??

 

[89custom]

good idea. try that. see how she goes.

 

[Justinlhc]

It will definitely help the problem if not fix it depending on how much extra fuel you're actually getting. Only takes a few seconds to give it a shot.