stalteri Posted December 6, 2005 Share Posted December 6, 2005 Anybody here have one? Has anbody done a oversize piston and cylinder? Looking to get alittle more out of it. Its a great bike and I don't want to spend the money on a new bike thanks.. Quote Link to comment Share on other sites More sharing options...
EY3BA11 Posted December 6, 2005 Share Posted December 6, 2005 During the research i have done on my WR426 I was thinking about going w/ the oversized and high comp piston... after all the research the big bore piston was worth it but the high comp piston wasnt worth it... If i remember right our current compression is 12.somehting:1 and the high comp pistons are 13.sumtin:1... the increased compression added more stress to the crank and crank bearings and you also had to re-shim the cylinder by adding a copper base gasket or something weird like that... it wasnt worth the time effort reduced durability of the engine and the increased cost of having to run race gas... Quote Link to comment Share on other sites More sharing options...
stalteri Posted December 6, 2005 Author Share Posted December 6, 2005 During the research i have done on my WR426 I was thinking about going w/ the oversized and high comp piston... after all the research the big bore piston was worth it but the high comp piston wasnt worth it... If i remember right our current compression is 12.somehting:1 and the high comp pistons are 13.sumtin:1... the increased compression added more stress to the crank and crank bearings and you also had to re-shim the cylinder by adding a copper base gasket or something weird like that... it wasnt worth the time effort reduced durability of the engine and the increased cost of having to run race gas... Yeah, thats what I'm trying to decide on. Max Power Inc has a 426 to 444 kit. Just don't know if its worth it?? Quote Link to comment Share on other sites More sharing options...
EY3BA11 Posted December 6, 2005 Share Posted December 6, 2005 YES its worth it... just dont go w/ the High Compression piston.. thats all.. Quote Link to comment Share on other sites More sharing options...
stalteri Posted December 6, 2005 Author Share Posted December 6, 2005 YES its worth it... just dont go w/ the High Compression piston.. thats all.. They said it was 12/1 and runs on pump gas Quote Link to comment Share on other sites More sharing options...
EY3BA11 Posted December 6, 2005 Share Posted December 6, 2005 12:1 is the regular compression for our motor.. and yes they still run on pump gas... allthough i mix my gas 50/50 half pump half race... i find i get a little cleaner throttle response outta it that way.. Quote Link to comment Share on other sites More sharing options...
EY3BA11 Posted December 6, 2005 Share Posted December 6, 2005 Read ME Another GOOD thread Between those 2 threads is where i have pretty much came up w/ my decision to not use the High Comp Piston.. Quote Link to comment Share on other sites More sharing options...
stalteri Posted December 6, 2005 Author Share Posted December 6, 2005 12:1 is the regular compression for our motor.. and yes they still run on pump gas... allthough i mix my gas 50/50 half pump half race... i find i get a little cleaner throttle response outta it that way.. Do you use the VP U4 or the 76 100octane? Quote Link to comment Share on other sites More sharing options...
EY3BA11 Posted December 6, 2005 Share Posted December 6, 2005 whatever is avalible at the pump.. which is usually VP c12 or f&l 111 i have strayed away from F&L because they were having seperation issues... so pretty much vp at the pump... Quote Link to comment Share on other sites More sharing options...
dunefreak Posted December 6, 2005 Share Posted December 6, 2005 VP at the pump? Where around here (vegas) is VP at the pump? Quote Link to comment Share on other sites More sharing options...
EY3BA11 Posted December 6, 2005 Share Posted December 6, 2005 I get it outside of Glamis.. i havent found VP at the pump here... the only race at the pump i know of is that rebel oil station and i believe its VP... Quote Link to comment Share on other sites More sharing options...
ONLY4STROKES Posted December 6, 2005 Share Posted December 6, 2005 I would go with the MaxPower 444cc kit. A lot of people seem very happy with it. No complaints. Check out the dynograph! http://maxpower-engines.com/big-bore-kits/yz444f.htm Quote Link to comment Share on other sites More sharing options...
EY3BA11 Posted December 6, 2005 Share Posted December 6, 2005 I was thinkin bout goin w/ the same one Only4Strokes.. only when i run across enough cash.. Quote Link to comment Share on other sites More sharing options...
stalteri Posted December 7, 2005 Author Share Posted December 7, 2005 I would go with the MaxPower 444cc kit. A lot of people seem very happy with it. No complaints. Check out the dynograph! http://maxpower-engines.com/big-bore-kits/yz444f.htm You know somebody that has this setup ONLY4STROKES? It sounds good to me (444cc) I talked to Will over there and he seems to know his stuff, i'm trying to see if I can get a better price from him but I doubt it. Are there any other brands out their or do you suggest this one?? Thanks Quote Link to comment Share on other sites More sharing options...
EY3BA11 Posted December 7, 2005 Share Posted December 7, 2005 Maxpower Engines does a REAL good job from what i hear... you might also want to try Kenz Cycle in Mesa, AZ as well... OR Eric Gorr at Foward Motion racing... both of those guys do good work as well.. the only problem with Gorr is he is a bit slow on his turn around time but does quality work.. Quote Link to comment Share on other sites More sharing options...
stalteri Posted December 7, 2005 Author Share Posted December 7, 2005 I was thinkin bout goin w/ the same one Only4Strokes.. only when i run across enough cash.. Maybe if you get one and I will get one we can get a deal??? Quote Link to comment Share on other sites More sharing options...
stalteri Posted December 7, 2005 Author Share Posted December 7, 2005 Read ME Another GOOD thread Between those 2 threads is where i have pretty much came up w/ my decision to not use the High Comp Piston.. I'm gunna go with you on this one ISBB no high comp pistion for me, looks like the 444cc big bore is the best bet for increased performance with less aggrevation in the long run.... Quote Link to comment Share on other sites More sharing options...
EY3BA11 Posted December 7, 2005 Share Posted December 7, 2005 Maybe if you get one and I will get one we can get a deal??? Im in the middle of a divorce so it will be a while... Quote Link to comment Share on other sites More sharing options...
sanddunesaddict Posted December 7, 2005 Share Posted December 7, 2005 I get it outside of Glamis.. i havent found VP at the pump here... the only race at the pump i know of is that rebel oil station and i believe its VP... its trick 111 at the Rebel station on Sahara and I-15 Quote Link to comment Share on other sites More sharing options...
EY3BA11 Posted December 7, 2005 Share Posted December 7, 2005 Thought it was vp.. ohh well... Ill have my little brother bring me another 5 gallons of race over christmas and still wont cost near as much as a can does.. Quote Link to comment Share on other sites More sharing options...
stalteri Posted December 7, 2005 Author Share Posted December 7, 2005 Hey ISBB, what do u think about a cam change with the big bore, is it necessary? I read some guys talking about it in those threads you sent out? Thanks for the help you have been very helpful we need to hookup for some and some .... Quote Link to comment Share on other sites More sharing options...
stalteri Posted December 7, 2005 Author Share Posted December 7, 2005 Well i'm going for it (444cc), does anbody know the difference between Thumper racing and Maxpower? Maxpower is about $100 bucks more than Thumper. I talked to Gary @ thumper he said they use the same parts that he knows of and dosent know why he is cheaper.. Has anybody used any of these guys or heard how good there work is? Thanks Quote Link to comment Share on other sites More sharing options...
EY3BA11 Posted December 7, 2005 Share Posted December 7, 2005 Stalteri920?? I was thinking about the cam change but if your comfortable w/ using the decomp lever like i am... All i planned on doin was the YZ time change on mine since its a wr i can rotate the cam one notch and get the same timing as you... its up to you... After watching brent and his buddy nick on thier new 450's kickin the crap outta em w/ the auto decomp and i fired up first kick it sorta changed my mind... The only thing you will gain is the autodecomp... so its just a preference thing... If you dont want to deal with the lever then do the cam swap... if you dont mind using the lever keep the same cam... BUT if you going to have it torn apart to send that stuff off i would suggest getting the head cleaned up a little w/ a little port job as well... since the thumpers make alot of power up top in the head.. Quote Link to comment Share on other sites More sharing options...
stalteri Posted December 7, 2005 Author Share Posted December 7, 2005 Stalteri920?? I was thinking about the cam change but if your comfortable w/ using the decomp lever like i am... All i planned on doin was the YZ time change on mine since its a wr i can rotate the cam one notch and get the same timing as you... its up to you... After watching brent and his buddy nick on thier new 450's kickin the crap outta em w/ the auto decomp and i fired up first kick it sorta changed my mind... The only thing you will gain is the autodecomp... so its just a preference thing... If you dont want to deal with the lever then do the cam swap... if you dont mind using the lever keep the same cam... BUT if you going to have it torn apart to send that stuff off i would suggest getting the head cleaned up a little w/ a little port job as well... since the thumpers make alot of power up top in the head.. Is there a place here in vegas that can do port job? I think I will leave the cam alone since i'm use to it now. Quote Link to comment Share on other sites More sharing options...
EY3BA11 Posted December 7, 2005 Share Posted December 7, 2005 i was goign to send my entire motor out to foward motion and do it... but i also hear there is a guy by the name of art who just built Sandy_YFZ's motor... and did a port job and the whole 9 yards... i have no idea how to get ahold of him but i hear he is a genious with engines.. Quote Link to comment Share on other sites More sharing options...
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