YSR80 vs. YSR50 motors - comparisons?

For those of you that have swapped out a 50cc for an 80cc engine (not YZ80 rather YSR80), what companrisons can you inform me of?

I'm talking accelaration/torque/and speed differences between the two engines. throttle responses, etc...

I'm acquiring a YSR80 motor shortly and would like to know how the 80 compares to the 50.

I've been told the 80cc YSR can cruise at about 72mph and can top out at about 85mph or so.

On my motor I'll have the 20mm carb, nology hot wire and the proper gearing (which by the way what is the proper gearing for an 80cc motor?)
Oh yes, and a tuned "pro-flo" pipe as well.

thanks.

The YSR80 pulls harder, but the overall ride is very similar. You'll definitely feel the difference in the 80 motor because of your size, it pulls the big guys along better. As for it topping out at 85 I don't think so. Maybe with one of your sons going on a steep down hill run at WOT maybe. The fastest I had mines was 64MPH with aide of a Security Forces guy (MP), and it took a while to get there. There seemed to be some left, but i was running out of road.

With the carb hotwire and pipe you can't go wrong, every little bit counts on the aircooled motors. E-mail me and I can give you some info as to what can be done to this motor.

thanks sir.
always appreciate your expertise.
I hear if you change the front and rear sprockets, it may take longer to get up to speed but "supposedly" you can reach a higher speed (the said "80mph" mark?).

I'll have to wait and see. i get the motor in 2 weeks or so. should be installed in 3 weeks or so. I'll have to play with the sprocket ratios.

What do you suggest? I've heard anywhere from a 39T to a 41T in the rear and a 14T in the front? I hear that the lower the ratio comes out to be when you divide the higher number by the lower........the small number equals the faster you go? is this true?

Oh yeah, one more thing..........and when you buy yourself your miniMC machine as your gong away present to yourself............you are going to sell me that sweet red "69" racer aren't you?

if we don't find a good NSR by then I suppose eh.

WOW! that's it?! :cry........you would think that you'd get at least mid 70's with an 80cc.

With my YSR 50 (2nd over, 24mm, Twin Stinger, 13/45) I hit 60ish....and that was in the twisties @ WOT

Rob, where'd you find your YSR80 motor and how much?....if you don't mind tellin'

I searched high and low for a YSR80 engine. I didn't want any YZ80 due to the vibration issues I've heard from so many riders.

this motor fell in my lap. a guy on another website was selling it so he contacted me and we made deal. I've sent him the money order already so it's just a matter of him packaging it up and mailing it off to me.

Here's what I got:
(1) -YSR80 motor
(2) - Pro-flo pipe for the motor
(3) - 20mm Mikumi carb (brand new in box still)

all the above for $800. I think I did ok. the seller says the motor is in great shape and I wanted a compatible swap in/out to the YSR50.

I already have the nology wire and the K+N filter so it's a no brainer.

I've spoken to Team Calamari and "Rose" (who works there) says she has a YSR80 on her bike and she can cruise at 72mph and top out at about 80-85mph. she must weight like 90 pounds or something.

...and her YSR80 is probably extremely well tuned (working for TCR and all)


In comparison, I've heard STOCK NSR80's top out at about 70mph, if that is true what can a "tuned" NSR80 top out at?

Very nice NSR80 specimen: http://amadaworld.cool.ne.jp/nsr80/


Oh and Good Luck with the swap!

Man, that is one sweet NSR80. wow, very good looking bike. I'm sure it begs to be riden hard eh.

thanks for the website.

I can't sell the red NSR80 because it's not mines, it's a team mates bike. You may be able to get into the low 70MPH range with a YSR80, but that's about it. AS for the NSR80, you can hit the 80MPH mark easy. There's no comparison between the two bikes and I mean NONE! THe NSR80's stopped beig made in '98-'99 that's why they're hard to come by.

The most difficult bikes to get are the TZM's and the NSR80's. For every 50 NSR50's at the auctions you'll see possibly one TZM, and maybe one NSR80 for parts. People aren't letting them go.

clane-you are a very knowledgable guy on these bikes so i gotta ask you some questions. I have a bone stock 97 tzm and a bone stock ysr50. Obviously i want more power out of both so i was gonna buy a ysr80 motor for the ysr and was wondering what options i have with the tzm? Also can i get top end kit for ysr80 locally in us, is it the same as yz80? Just wanting to see what my options are for my ysr and tzm.

YSR80: It's not the same as the YZ80, it might be close to the early 70's models. Add a 20mm carb, remove the oil pump, add a good pipe, and a cross ratio transmission (keeps the engine in the sweet spot). I tried to have my YSR bored up, the most the cylinder could take was an additional cc, 80cc even. That's about the end of the road for the YSR. Unless you get a few TZM parts, front and rear to drop some weight.

TZM: Different story. You go from 64cc's (63.8) to 70cc's (68.7), there are plenty of aftermarket pipes available made just for the TZM, 20 to 32mm carb no problem. An aftermarket CDI is a must, and a good plug wire. I strongly reccommend a YEC shock (ride height adjustable, the whole nine yards. I paid $450 for a new one.), the only thing better is a Quantum and they cost $1,500

You can't go wrong with either of the bore up kits, they pull like crazy.The TZM has a pretty good aftermarket.

I'm going to ask you a few questions soon. I've been looking into purchasing a bike like the Hydra. Now I'm tied up with a lot of projects.

dang..maybe ill keep the ysr stock and just hang onto it as a collector. Does anybody make cool body kits for the tzm?? ask away about the hydra

They Just came out with the YZM-1 kit, it's pretty SIICCKKK! The rest of the TZM bodywork is the same as the pic I posted in the project section. What you do with the paint depends on how well it will look.

I would've ordered it but it wasn't out yet, and I only paid $75 for the upper/lower and screen. I already have a very nice seat.