hybrid.mx.11
09-22-2009, 02:47 AM
i was sittin here and came up with an idea to post a serious thread concerning the crf 450 motor and what it takes to fit one in a frame all the modifications you would be looking at and the technical side of it like my big question what is the perfect degree for the motor in the chassis ill post my problems and answers and the rest of you can follow up
lets start with
*mounting the radiator which involves welding brackets for it and having the right grommets for it to sit in/and the radiator cap not being an inconvenience
*making your own motor mounts in the front and the top i had mine cut from steel (the aluminum one cracked slightly) i only have one on the top right side of my 250r geo frame and i dont have one on the bottom havent had a problem yet
*the carb is a hassle i had a 400ex frame and it had a tube welded into the frame but i just didnt have the mind to cut into my arens frame so i made a carb boot that tipped the carb slightly higher and have the 400ex airbox and connecter and have had no problems
*wiring harness is pretty self explanitory but its not my strong point any questions though ill give you the best ive got
*the motor angle im not sure on i do know that it cannot be to low though because the chain will be pulled into the swingarm and guide and it will be all chewed up
*another thing i have been fixing is a stock shock will rub the motor and the exhaust an aftermarket shock is a real quick fix but grinding some of the resovoir can help(which is filled with fluid you will be needing....just be careful) the exhaust problem is the nipple on the stock shock res. rubs the exhaust. some true header wrap will fix this and i mean the thick cloth like exhaust wrap not the crummy stuff you can get at auto zone
*i am putting loc tite on every bolt i can the motor has vibrated my engine mount bolts out
*gearing is VERY important i blew one motor up because the track was just a little too long for the 40 tooth sprocket which now i personally feel is quite a bit too much id say 36 teeth with 18 inch tires 38 on shorter tracks
*i have a cooling fan connected the a battery in my airbox i use it for staging and long periods of idling or you can get the flywheel? i think that will give you the abilitiy to run one off the motor
*the trx 450 exhaust header and tip work well for alot of people im seeing it more and more i use it also
*the kick starter ive seen all kinds of different ones but a splined extension is great i have used a custom one using the original splines from the kickstarter and just made to work around the frame * this part can make it real tricky on a project if nothing else
have a buddy push start you AND DONT KILL IT!
*** ALL OF THIS CAN BE PREVENTED BY BUYING A CRF FRAME!!!!!!
you can pm me if you need anymore help im far from professional but very serious about it if you need help let me see what i can do for you
lets start with
*mounting the radiator which involves welding brackets for it and having the right grommets for it to sit in/and the radiator cap not being an inconvenience
*making your own motor mounts in the front and the top i had mine cut from steel (the aluminum one cracked slightly) i only have one on the top right side of my 250r geo frame and i dont have one on the bottom havent had a problem yet
*the carb is a hassle i had a 400ex frame and it had a tube welded into the frame but i just didnt have the mind to cut into my arens frame so i made a carb boot that tipped the carb slightly higher and have the 400ex airbox and connecter and have had no problems
*wiring harness is pretty self explanitory but its not my strong point any questions though ill give you the best ive got
*the motor angle im not sure on i do know that it cannot be to low though because the chain will be pulled into the swingarm and guide and it will be all chewed up
*another thing i have been fixing is a stock shock will rub the motor and the exhaust an aftermarket shock is a real quick fix but grinding some of the resovoir can help(which is filled with fluid you will be needing....just be careful) the exhaust problem is the nipple on the stock shock res. rubs the exhaust. some true header wrap will fix this and i mean the thick cloth like exhaust wrap not the crummy stuff you can get at auto zone
*i am putting loc tite on every bolt i can the motor has vibrated my engine mount bolts out
*gearing is VERY important i blew one motor up because the track was just a little too long for the 40 tooth sprocket which now i personally feel is quite a bit too much id say 36 teeth with 18 inch tires 38 on shorter tracks
*i have a cooling fan connected the a battery in my airbox i use it for staging and long periods of idling or you can get the flywheel? i think that will give you the abilitiy to run one off the motor
*the trx 450 exhaust header and tip work well for alot of people im seeing it more and more i use it also
*the kick starter ive seen all kinds of different ones but a splined extension is great i have used a custom one using the original splines from the kickstarter and just made to work around the frame * this part can make it real tricky on a project if nothing else
have a buddy push start you AND DONT KILL IT!
*** ALL OF THIS CAN BE PREVENTED BY BUYING A CRF FRAME!!!!!!
you can pm me if you need anymore help im far from professional but very serious about it if you need help let me see what i can do for you