i need advice on engine and jetting

[blade88]

im looking to do an over haul on my engine.i want to put a BB stroker on it but i heard the 4mm blows the tranny out.so is a 3mm better or the 4mm.i dont want to break anything.also i need help with jetting BB,hot rod stroker,toomey pipe kit,roost boost cdi,26mm carb,torque plate,v4 reeds,K&N airfilter,port and polish.i would also like to know if it is possible to regear the sprockets to run a set of Dick Cepek Spider Tracs they are 22 12.50 8

 

[Awk08]

i heard the 4mm blows the tranny out.so is a 3mm better or the 4mm

no and no.
a +3mm is easier as it doesn't require trenching the cases.

is that a wish list or you already have these parts ?
if just a wish list, lets get them bought and built then we'll go over jetting suggestions.
a bigger carb will work better for all that than the stock 26mm
no sense to figure out jetting and things change or never happen.

yes you can gear for those tires, depending if you want more bottom end grunt or more top end speed

and please tell us where you got a roost boost for a blaster ?
and pics of it hooked up ?

 

[79 bronco]

I did a +4mm stroker and i had to to trenching the cases for it, and that makes the cases thin! I will probably never do a +4mm again! The +3 is safer, and i dont think you get much or any more of a power gain with the +4 over the +3.
Get a UNI filter! NOT a K&N!
Wow a Roost Boost! Haven't heard of that since the 90s.

 

[blade88]

so a 3mm and a BB or no BB and the parts are being bought and the roost boost is on my blaster and has been there for over 10 years the quad was my dads for 10 years and it was there when he bought it and it had a BB on it when he bought it it was raced it had a 22 7 10 on the left front and a 21 7 10 on the right

 

[blade88]

i cant find a 3mm stroker kit from hotrods anywhere amazon,ebay,or the hotrods site can someone send me a link to get one if not im gonna get a 4mm stroker

 

[Awk08]

i cant find a 3mm stroker kit from hotrods anywhere amazon,ebay,or the hotrods site can someone send me a link to get one if not im gonna get a 4mm stroker

thats because hot rods only makes a stock stroke and 4mm stroke.
your cases will need trenched to use a +4

vitos makes a stock stroke and the +3 stroker.....
https://www.vitosperformance.com/atv_parts/home.php?cat=250

for the +3 crank you'll also need the spacer plate/gasket combo at the top of that page, unless you're having the porting/head adjusted by a professional. no case trenching required.

 

[blade88]

if i put a ct racing 240 super sonic top kit and stroke it 4mm will i have to run race fuel???or can i still run pump gas?

 

[Awk08]

if i put a ct racing 240 super sonic top kit and stroke it 4mm will i have to run race fuel???or can i still run pump gas?

If you have the big bucks for a new CT sonic kit, the cost of race fuel shouldn't bother your wallet.
go on CT's website and see what they recommend for that kit.

 

[79 bronco]

When you call CT Racing tell them you want to run just pump gas! The should be able to set you up with what you want!

 

[best]

BBK and Stroke kit by themselves is not massive power, only 25% larger than stock and typically lower rpm. Try multiplying 17hp by 1.25% and see if you can get excited about it. The Vitos head design is very similar to stock, so not a great gain there. A rechambered head, a bit of conservative porting, a good pipe and open the airbox will out power a BBK and Stroke kit.

If you don't know jetting, a CT Sonic kit or 4mm stroker might be quite a jump for you.
It would be a shame to ruin the kit because you just don't know.
The formula mentioned above, rechambered head, conservative porting, a good pipe and open airbox, will jump your power from the stock 17hp to over 30 screaming hp. Once you master that, and know how to jet it, you are ready for a CT Sonic kit or stroker.

Same goes for high octane racing gas. Unless you are racing, why?
Build the engine for the fuel that is available.

Steve