best motor for a custom street bike

dopaytoplay

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May 20, 2016
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Byron. CA
Ok guys I just sold my Yamaha 1985 rzv500 v 4 two stroke street bike. My buddy that makes custom frames want's to do a bike for me with a two stroke snow mobile motor. He also make's a very trick 5/6 transmission that we will be using in it. what I need is what do you guys think is the best motor to use. I also want to have electric start. Need some idea's. here's my one of my old bike's looks cool but only had 90 horse power I love two strokes I Grew up with kawasaki h1's/h2's14.jpg
help me out guys
 

SRX obviously comes to mind. 142 hp. I have no idea of what the mechanics to make this work would be. If a 3 cylinder is too wide there are a few newer 2 cylinders of the other 3 brands making good hp. Can't be as durable as SRX but how many miles will this bike be ridden.

Sent from my SM-G920V using Tapatalk
 
Maybe the 600 twin if room is a concern. The old xt 600? Srx or viper triple would be great if you have the room. With simple mods should be able to see 155hp without to much trouble.
 
ive seen a few bikes made with the triple engines already. If space is an issue the single piped redhead and viper would be better.
 
How do you even get banned on here? I mean what would you have to do to get banned? Maybe he just liked (ski doo) lol
 
I'm back lol. There was a little glitch from the website. I have seen that other bike online . I think we can do way better. I don't like where his pipes are they need to be seen and two shocks really! Also he turned the motor around so the carbs are in the front so he could do his pipe's like that.
Thanks Jay
 
The Vmax-4 engine evolved from the engine used in the TZ750 race bike back in the 70's. H2's couldn't keep up with the TZ.

The Vmax-4 engine has more power than the TZ and much easier to control. The crankcase is setup for a plug in electric starter like many bikes use but the machine work was never done on production engines.

Have your buddy incorporate a starter into his trick trans and that issue is solved.

opsled
 
guys,

I was wondering if someone could give me the measurements of the motor (top to bottom, side to side without the clutch, and front to back with and without carbs on it? I'm trying to see what is going to fit my requirements the best.

Yamaha SRX Triple
Thanks jay
 
Vmax-4 engine measures 25" wide recoil to end of pto shaft. 14" high to top of spark plugs. 13 1/2" front to back without carbs and engine mounts. 16 1/2" with carbs, no mounts.

Smooth as glass, will make more HP than a triple, last longer and sound better. Thirsty m-effers though. Triples get much better mileage.

Go here for engine pics. This one is a preproduction 750. Production 750's and 800's are basically the same.

http://s808.photobucket.com/user/op1961/library/OMUO-2B008 engine build?sort=3&page=1

opsled
 
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Vmax-4 engine measures 25" wide recoil to end of pto shaft. 14" high to top of spark plugs. 13 1/2" front to back without carbs and engine mounts. 16 1/2" with carbs, no mounts.

Smooth as glass, will make more HP than a triple, last longer and sound better. Thirsty m-effers though. Triples get much better mileage.

Go here for engine pics. This one is a preproduction 750. Production 750's and 800's are basically the same.

http://s808.photobucket.com/user/op1961/library/OMUO-2B008 engine build?sort=3&page=1

opsled

Thank you very much, opsled.

That is exactly what I wanted, and the pictures were even better! That might be a little big for what I'm trying to do. I'm trying to keep the chassis at 55-56" long. If someone can give me the SRX measurements (or any other good two stroke snow mobile motor that might work), that would be perfect.

Thanks,
Jay
 
IMO, For what your looking to do. Arctic Cat F7 motor. Everything is going the right way, plus a single pipe 140hp, low CG, small, endless hop up parts, cheap..
 
IMO, For what your looking to do. Arctic Cat F7 motor. Everything is going the right way, plus a single pipe 140hp, low CG, small, endless hop up parts, cheap..

it wont have the sound and character of a triple screaming down the road and thats what a custom build is all about.
 
Hi what do you mean going the right way? I see the carb and pipe are on the same side. I want this to look like it came from the factory. I also need electric start so we can get rid of the pull cord.
 
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Most sled engines e-start spins a ring gear on the clutch. If you aren't going to use it the e-start system won't do you any good.

Most Yamaha fan cooled engines had e-start at the flywheel. The only liquid cooled (I'm aware of) that used the flywheel for e-start are the Exciter 570 and Vmax 5/600 sleds.

opsled
 
Most sled engines e-start spins a ring gear on the clutch. If you aren't going to use it the e-start system won't do you any good.

Most Yamaha fan cooled engines had e-start at the flywheel. The only liquid cooled (I'm aware of) that used the flywheel for e-start are the Exciter 570 and Vmax 5/600 sleds.

opsled

I have seen that. We are planning to use just part of the inner clutch and then mount our gear on the inner clutch shaft to the tranny. We are planning a belt or a chain drive to the transmission. We will then balance after that. Do you think that will work? Here is a pic of my rzv 500 with a ducati 1098 dry clutch. also a pic of my h1r copy I sold last year. Any help or idea's are appreciated! I have never even ridden a snowmobile. I have had all the old two stroke street bikes though. I know the new two stroke motors are trick as hell. This bike will be done right!!
Jay
 

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