fixitrod Posted November 5, 2003 Report Share Posted November 5, 2003 Just trying to find out if anyone here runs a 4mm stroke on their shee. I may be getting one sense my crank went BOOM!!!!!! Just wondering where the power increase was. Thanks Quote Link to comment Share on other sites More sharing options...
sean10 Posted November 5, 2003 Report Share Posted November 5, 2003 I put a 4mm hot rod crank into 421 cheetah and you can feel a good deal more bottom end and if i lug the bike it still pulls instead of shifting gears up hills. Quote Link to comment Share on other sites More sharing options...
WickedBanshee Posted November 5, 2003 Report Share Posted November 5, 2003 they add alot of torque. Quote Link to comment Share on other sites More sharing options...
fixitrod Posted November 5, 2003 Author Report Share Posted November 5, 2003 I put a 4mm hot rod crank into 421 cheetah and you can feel a good deal more bottom end and if i lug the bike it still pulls instead of shifting gears up hills. That's what I want. I'm not doing the big bore yet. I have to many good bores left in the cylinders. Do you think the low end gain was from the crank, pistons or just a combination of them both? Quote Link to comment Share on other sites More sharing options...
H300F Posted November 6, 2003 Report Share Posted November 6, 2003 Im building mine now. I have everything sitting here waiting. I have to put my whole quad together too. I will let you know in 3weeks. But not only will the crank do a lot but the porting is going to change shit (which you will need done). I am going to try to run stock carbs on it for now with pt mids. see how she reacts!!!! Quote Link to comment Share on other sites More sharing options...
H300F Posted November 6, 2003 Report Share Posted November 6, 2003 sean10, does the crank make so much more lowend, that it will make pipes like CPIs have good lowend almost like a pt mid or am i asking for too much? Quote Link to comment Share on other sites More sharing options...
MRMOONEY Posted November 6, 2003 Report Share Posted November 6, 2003 THE BOTTOM END IS UNREAL, I JUST DID MINE, GRANTED THE PORTING IS NOT RIGHT FOR MY DRAG BIKE, IT HAS TONS AND TONS OF LOW END, I RUN CPI'S ALSO, IT WILL LAUNCH IN THE SAND, WITH A 15,40. AND I WEIGH 240LBS, ITS UN REAL Quote Link to comment Share on other sites More sharing options...
fixitrod Posted November 6, 2003 Author Report Share Posted November 6, 2003 Okay Okay, I'm going to do it. My parts are sitting at grand river racing right now. I'm having him port the cylinders with his pro port and cut the head for the pistons to fit inside. Now I can't wait. MrMooney, who ported your cylinders? Quote Link to comment Share on other sites More sharing options...
chase73 Posted November 6, 2003 Report Share Posted November 6, 2003 I have mine and its should be completed by around the 17th .I am having Patroit Racing do all the port work and the head modifications. Dan AKA backcountry is great he goes out off his way to help you and make the right dicisions. You definitly need to change the prting for the new 4mm crank. With the mods I have and switching to race fuel I will be in the high 80's-90 HP range I went with the 410cc cant wait. I will give a full review after I get it running again. Blue Deuce is having a 4mm built for him by Passion he will be running a 370cc engine he will give you a review after his is done as well. Quote Link to comment Share on other sites More sharing options...
chase73 Posted November 6, 2003 Report Share Posted November 6, 2003 I have mine and its should be completed by around the 17th .I am having Patroit Racing do all the port work and the head modifications. Dan AKA backcountry is great he goes out off his way to help you and make the right dicisions. You definitly need to change the prting for the new 4mm crank. With the mods I have and switching to race fuel I will be in the high 80's-90 HP range I went with the 410cc cant wait. I will give a full review after I get it running again. Blue Deuce is having a 4mm built for him by Passion he will be running a 370cc engine he will give you a review after his is done as well. Quote Link to comment Share on other sites More sharing options...
MRMOONEY Posted November 6, 2003 Report Share Posted November 6, 2003 mine is getting ported right now by mp racing they do greay work should have around 90+horse on alky that is, he says it will run mid 4 to low 4's in the sand drags, well see i guess. dave at mp racing is a great guy he gives me all kinds of deal. give him a call. ill let you guys know in a few days how it runs Quote Link to comment Share on other sites More sharing options...
sean10 Posted November 6, 2003 Report Share Posted November 6, 2003 H300f, the motor is a 421 cheetah with the powervalves so theres a combination of things working to help the bottom end. I use Rocket pipes with it, which is suppose to be more of a high end pipe than cpi's, and the bike has 15 41 gearing and a 10 in. swing arm. It does second gear launches lifting the wheeles up until i shift to next gear. Thats in sand with a nine paddle haulers. Thats telling me somethings helping my bottom end. My 410 big bore has to be geared down to 13 45 to have the same kind of launch out of the hole. Quote Link to comment Share on other sites More sharing options...
fixitrod Posted November 6, 2003 Author Report Share Posted November 6, 2003 Powervalves will do that for you. Being a 421 sure has to help too Quote Link to comment Share on other sites More sharing options...
H300F Posted November 6, 2003 Report Share Posted November 6, 2003 Ok sounds great. I had Jim at Passion Racing do my porting. Claiming 85+hp with the right pipes and carbs, but for now I will have it mild with the midpipes and stock carbs, until i can afford to try Cpis and 34s. Quote Link to comment Share on other sites More sharing options...
MRMOONEY Posted November 7, 2003 Report Share Posted November 7, 2003 mine will launch in 2nd with 15-40 and wheelies till i hit 4th gear, but i only got a 6inch over arm and +8 in the front, i made my self a drag frame, hopefully it wont have so much damn torque after its ported. Quote Link to comment Share on other sites More sharing options...
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