need help with possible CRF hybrid

[trx/lt500r]

I have a nice lonestar hybrid frame in the garage. I am new to four strokes. I am thinking of building a CRF hybrid.

What year engine is the best to use?
Does the CRF require an oil tank?
What is the toughest part of the build?
What is the best pipe to use?

Thanks for your time

[mooseracerX]

There is a few different thoughts on years. I have a 2003 in mine and I've heard lots of people liking the 03. The 05 seems to be a popular one too. The CRF doesn't require a oil tank like the yz426's do. For us we just used a stock 400ex frame, but with a Lonestar frame it shouldn't be nearly as hard. Probably for us the hardest part will be jetting and getting the motor to start easily. Lots of people like Rossier or Sparks. I use the LRD Pro 4.

[trx/lt500r]

thanks for the reply.

I was wondering if anyone had any thoughts on the gearing. Is the motorcycle engine gearing suited for the atv frame? I do a lot of woods riding as well as haul road WOT riding. Is the gearing practical for the ATV frames?

Thanks

[mooseracerX]

Your welcome. I'm not sure you could get that gearing to work because they don't make that big of sprocket for an ATV. I'm going to try 13/36 and 13/38 and see how that works. For the woods you'd probably want 13/40 but that would cut your top speed down depending on what size tires you plan on using.

[deathman53]

mine uses a 13/38 and I use 18" tires. It definitely lacks top end. When I used 20" tires it still was somewhat slow, but not as bad. Most of the people who use them, do mx, where most of the time, the only gears used are 2-4, 5th being rarely used. I considered going to a 36t rear sprocket, but first gear and second gear would be way too tall. If you do woods riding, I would use a crf450x motor or if you are determined to use the R motor, get the different tranny gears that baja designs used to sell(big item with enduro riders using crf450r's). I did some trail riding with mine and it isn't much fun, 1st being too low, second being too high forcing you to ride 2nd and clutching alot. Also E-start can be nice item for woods riders, especially if stalled on a hill, given that, you still want to use a kicker extension, if you need to use it. I know this is a honda site, but the best hybrid motor for mx and woods is the 03/04 yz450f motor, gear ratio's and almost perfect when ~13/38 gearing is used.

[trx/lt500r]

thanks for the info

[quadfmx]

so if u call u some of the ehxaust compaines listed and say i got a crf quad witha walsh or whatever frame they got exhausts for it, i thought u had to piece it together with a couple diff exhausts, but its was just other posts i saw

[quadfmx]

so if u call u some of the ones listed and say i got a crf quad witha walsh or whatever frame they got exhausts for it, i thought u had to piece it together with a couple diff exhausts, but its was just other posts i saw

[mooseracerX]

Some exhaust companies used to make exhausts for hybrid frames. We just used the LRD Pro 4 full system off of a 04-05 TRX450r. We welded mounts onto the subframe and put longer studs in for the header to fit. Other than that no piecing together was required for this on my stock 400ex frame.