big bore kit for 2008 honda foreman 500

[johndeereman346]

im looking for some help on a big bore kit for my foreman i have found one from high lifter but am wondering on either a shop around red deer ponoka or camrose that could do it unless a modes mechanic could pull it off.

 

[lucm]

it seems to me that it would be cheaper to just buy a bigger quad.......I'm not sure how much extra you will be able to get out of that quad?

 

[johndeereman346]

this modification is not for power the 500 is just enough to have fun and not be stupid, the bore kit is to make this bike a little bit different, and as far as the financial aspect not a problem.

 

[brianwmcdonald]

From what I've heard, most people have trouble with bir bore kits on air cooled engines. I believe the cylinder walls aren't thick enough and it causes the motor to run hot and head to warp. Just what I've been told. If I were you and you're just looking for a bit more grunt I'd go with a gear reduction from highlifter and a clutch kit.

 

[Cramleon]

I have put a big bore kit in my honda atv and did not have a single problem with it and I noticed a big difference in power and throttle response. If you take the engine apart and bring the cylinder pot and the big bore kit to a machine shop they will do it for you.

 

[leonard]

you could always have it honed and put a 12:1 Wiseco stock size piston in it and a cam.

then you retain the wall thickness pick up a bunch of compression and a more aggressive cam.

go with a Web Cam they make good cams.

I agree on the not over boring that air cooled motor i was going to a do a 350 up and was told the same thing guys get less motor life sometimes really short with these air cooled motors once they start boring them out.

plus alot of the performance gain you will get is the compression anyways thats what give you that snort and performance.

hear me out. Stock CC 12:1 Wiseco piston - Web Cam " you will have to check into what grind" - get a little bit of port and polish done on the head - and open up that airbox some you might have to modify what filter K&N or Uni and the snorkel on the air box not like a Snorkel but the stock ones on these bikes are restrictive you may need to just make it bigger like a 2" hole with some 2" marine hose coming up to where the stock one went.

throw a slip on pipe on it like a HMF Swamp-series and it wont be much louder than stock.

you will gain alot with these mods. the gain vs reliability of boring it over on a air cooled motor doesn't seem worth it to me when you can do so much else to bring reliable power to it.

depending on the Grind of the Webcam you might want to talk to them. you might need to get some kibble-white valves/springs so you dont get floating valves.

when ever you dig into a motor there is 100 things to consider.

also a timing chain might be a good idea also alot of people recommend you change it out to avoid stretch problems re breaking in everything.

 

[peckerwood]

no offense but how much do you really know about a honda foreman? the reason i ask is because a foreman and any other honda utility atv is a pushrod motor. no cam chain. i'd think about talkin to your local dealer. also just an idea, and mind you i've done no research, but would a rubicon connecting rod work on a foreman 500. the bore on the 2 machines are the same but there is 3.5mm difference between them. rubicon bein bigger. anyone know then enlighten me. i'd like to know.

 

[leonard]

sorry i assumed the current 500s were not of same design. ie" push rod" i for some reason thought they had changed to timing chain setup

because even my 350 has a camshaft chain and tension-er im looking at it right now in my service manual.

right out of the 350 TRX manual.

CAMSHAFT REMOVAL
Clean the mating surfaces of the head cover and
cylinder head.
Blow through the oil passage in the head cover
with compressed air.
Install the following:
Install the cylinder head cover and tighten the four
bolts.
Install the heat guard and fuel tank (page 5-17).
cylinder (section 8)
flywheel and starter driven gear (section 10)
Remove the following:
new gasket
new O-ring (coat with engine oil)
Remove the cam followers.
Remove the two bolts and cam chain tensioner
lifter.
After removal, push in the tensioner shaft while
pressing the stopper block to retract the tensioner
and secure it with a pin

CYLINDER HEAD/VALVE
INSPECTION
7-16
Remove the following:
tensioner pivot bolt
tensioner slider
washer
retainer bolt
bearing retainer
camshaft
cam chain
.

 

[airbat]

they still have a cam chain , its just short ,goes from crank to cam in the bottom end .

 

[leonard]

yea i coulda swore they did when we took apart the 350

 

[peckerwood]

they have a chain. the way you described i took it as you meaning a over head cam.

 

[peckerwood]

has anyone found out or know if a rubicon crank shaft work in a foreman 500. the rubicon is slightly longer