YSR 80 engine?

I have a very nice street legal YSR50, having a lot of fun with it on street and track but I'm thinking it's time to drop in a bigger engine. Anybody have a YSR 80 engine for sale? Or a recommendation for another engine that would be an easy conversion?

 

go to ysr50.com
there are a bunch of different engine swaps you can do.
Everything from xr100 to yam blaster 300cc to what ever people can stuff in there...
I think the xr100 almost bolts in, as well at the Yam Dt100.

 

best bet would be a CR250 engine. Late 90s works best.

Anything larger and youre gonna have all kinda of other problems...lol

 

ysr80

an older aircooled yz80 engine will drop right in with no mods.

 

Thanks for the suggestions. I definitely want an EASY drop in. I'd rather pay a little more for a YSR80 engine if I can find one. I 'll look into the YZ80, though.

I already went through an experience of a mechanic recommending that we put in a YZ85 motor (I think that's what it was, anyway) but once he got started he came back with a list of mods that was way more than I wanted to tackle - adding a radiator (custom), custom motor mounts, loss of kick start, and I can't remember what else, so I gave up on that and sent the original 50cc motor off to TCR for rebuild. I have no idea if the guy knew what he was doing, but I definitely didn't.

I do have that nice Darcy motor still in the crate, with a go-kart exhaust for it, in case anyone is interested!

I'll check out ysr50.com, too, thanks.

 

If you cant rebuild a basic 2 stroke engine...whats gonna happen when the swapped motor goes bad?

The YSR isnt especially hard to change a top end on.

 

don't get an older yz, you'll want more. I put a water cooled CR85 in a YSR. The thing was stupid fast. Didn't have to do much fab work either

 

Hm, you lost me on that one, rebuilding the engine isn't a problem. I was just commenting that when I first got the bike, YEARS ago, I sent the engine (the whole bike, actually) to TCR for total rebuild, they do an exceptional job. Since then I have done a couple of rebuilds on it. Rebuilding is no problem.

I just want a higher horsepower engine for it, that can be dropped in without massive amounts of effort and creativity to make it fit. And I want to keep it (reasonably) street legal. I'd prefer to keep THIS bike instead of buying a different bike that already has a bigger motor stuffed in it, because this bike has tons of upgrades and a custom paint job, and I like it.

And, although I definitely appreciate advice and suggestions, what I am really looking for is someone with a motor for sale!

 

sorry guess I misread your post.

 

i used to race ysrs on a small tight track. we had some stock ysr50s, some with watercooled cr 80 motors and some with cr125 motors. the 125s were stupid fast and hard to keep the wheel on the ground. the aircooled yz80 engine with a big carb on it was as fast on the tight track as the watercooled 80s. yes if the track was longer then the watercooled would have been faster. guess it just depends where you are going to ride it. one quick note. the 125s and the watercooled 80s did vibrate bad. the aircooled dropped in and did not vibrate to bad. put a good pipe on it and a big carb and maybe a little porting.

 

DT175 fits right in, biggest problem is gearing, top speed was 70-75 and first 3 gears were insane wheelies. With the short wheelbase and short gearing wheelies were very hard to ride so most ended with the front slamming back to the ground, steering stem finally snapped, had that welded and gussetted and put stock 50 back in.

 

Ok judging from what ur saying, you should defenetely stay away from anything liquid cooled (the YZ and RM 80-85cc are a pretty easy fit..but you do have to custom fit a Rad...and weld to mounting brackets "one under the engine"+ "1 at rear of the engine+ fitting a new pipe could also prove to be challenging, especially if you want to keep the fairings intact). by the way i've done this, and you could see pics here:

http://motoadrenaline.com/gallery/MINIGP-Yamaha-YSR-rebuild-P1cs

The easiest mod would be for you to find a YSR 80cc AIR COOLED) engine complete with carb and pipe, it fits in and mounts exactly the same as the 50cc engine. So unless you misplace some nuts and bolts, you absolutely do not need to go look for this or modify that.

the only challenge for you is to find the 80cc YSR engine as they were only sold in CANADA and JAPAN. I had YSR 80 with a nice engine with a fresh Not even broken in TOP END. But i sold it this last month. he plans to race the bike,... if you wish i could contact him and offer him a RM80 engine in exchange for the YSR 80 and see what he says.

 

Thanks for all the great info, especially the tip about the vibration on the liquid cooled engines, good to know.

I agree that a YSR80 engine would be the easiest (anybody want to sell me one?) and I do want to stay with a reasonable size engine. I already have one big, scary, overpowered bike, I'd like to keep my little YSR fun and manageable!

Ducati366, yes I might be interested in contacting the person that bought your YSR80 engine, PM me, if you get a chance.

 

Why loss of kick start? That one loses me... Please help me figure that one out!

 

here's my YSR I built with a CR80 in it

YSR CR80

 

Obviously you have not yet tried to fit the lower fairings,
With those engine mounts you will not ride the bike more than 40hrs, i guarantee you that.
did you ever start the bike? tell us how it rattled, and what came undone when the bike was simply idling.

I've built a YSR with a cr80 engine, you're nowhere near done, if you need tips let me know by pm.

 

Actually, I don't know, but I think it interfered with the fairing or maybe there just wasn't a clear space to kick it. He just told me I'd have to go to bump start only. We didn't get far on the project, this was a friend of a friend that suggested the conversion and had a motor, but once he started on it I realized he didn't know what he was getting into, so eventually I just went to his shop and retrieved my bike. Or, should I say, the numerous boxes of small parts that had once been my bike!

That was such an annoying sideline that I decided to ship all those little boxes off to Team Calamari, they did their magic and shipped me back a nice little running YSR that has been a great ride ever since.

 

FInd an old gt80, mx 80, dt80. The motor+ electrics are plug and play, You can use a stock pipe or any other used for a ysr with out mods.

If you really want some power, take the ysr cases +transmision, use the gt80 clutch setup, gt80 crank (you will need a thin spacer made to go between the crank cases and the cylinder head) Use the ysr top end, but put in the big bore ysr piston, and have the cylinder ported, polished, and opened up for a yz 60 or early yz 80 rear block. Add a nice pipe, and 24mm carb and that bike will screammmmm.


Ive had several of those built. The are about 70cc or so. but man are they fast, and reliable.

 

i have a blown up gt80.

 

I never had fairings on it. I sold it before I ever mounted them. I did ride the bike a few times. It was stupid fast. All it wanted to do was wheelie 1-4th if you got on the throttle. Trying to launch good was impossible, even with the longer swing arm that was on it. It actually vibrated worse when idling than when riding it. Nothing ever fell off. Everything was lock tite or safety wired on it.