porting,carb,mods?

[Quadrider10]

ok im confussed now......

rite now i have

fmf gnarly pipe
fmf powercore 2
.30 over
boysen single stage reeds
and maybe a weisco piston. i have no idea tho. (previous owner dosent know)

this winter i am gonna do a home port job, +4 timeing, and shave the head a tiny bit. i heard that a stock carb will hold the motor back if there is a port job. even if jetted. and i also heard that a bigger carb will also hold it back, and make it run rich or lean.....etc. what would be a good size carb for those mods? 28, 29mm?

 

[NOVIS]

im not very educated in switching carb sizes. but i would bet a 28mm would do ya good

 

[Quadrider10]

a thats what i was thinking.... im not going crazy with mods. the only other thing i may get in the future is dual stage reeds. but thats pretty much it.

 

[Quadrider10]

alright 28mm it is! lol and the head mod i want to do. basically i want to take the head off, lay down some sand paper on the floor, and rub the bottom of the head on it to shave off like .5-2mm. most likely 1mm. i know this will rais compression, is there any negitive sides to this?

 

[Larry's Shee]

How do you plan to measure the amount you take off? At least use a piece of glass if you do it. Really consider sending it to Ken O to gain max benifit from head mod. Depending on how the porting goes , 30mm would be good choice.

 

[Triplecrown421]

with the stock chamber in the head you may run into detonation. most people on here say they dont but i did when shaving the stock head. Supreme fuel for sure

 

[Blaaster]

alright 28mm it is! lol and the head mod i want to do. basically i want to take the head off, lay down some sand paper on the floor, and rub the bottom of the head on it to shave off like .5-2mm. most likely 1mm. i know this will rais compression, is there any negitive sides to this?

If you use plate glass instead of flooring, This method is fine to just clean up and true the head, .

Removing a lot of material is best left to the professional with the correct tools!

No matter how careful you are, you are not going to get a level head at the end of all your labour.

 

[JBRoc01blaster]

Yeah bro if your gonna do it ( which I'm sure you can ) use at least a 3/8 in. thick piece of glass or any true known flat surface so you don't get any low spots that could create an air leak. There's a great DIY on " lapping " that tells you in detail how to shave your head. And the only downside I can really think of from raising your compression is that once you hit a certain psi ( I believe its around 180 ) premium 93 gas won't cut it anymore, and you'll need to run higher octane gas which is damn expensive haha. There's a thread somewhere on here that has a chart showing the octane required depending on how much you shave off your head. I believe 0.20 - 0.30 is the most you can take off and still run 93 but don't quote me. Read up on that lapping thread and go for it, it probly won't be nothin in comparison to what KOR can do, but success in increased performance can still be acheived doin it yourself. Good luck bro, let us know how it turns out if and when you do it.

 

[blasty 95]

I'm running a keihn pwk 28mm with all my mods.. personally id leave it to the pros for the head work.