YSR motor swap info...

[airdreams1]

~~~Please read & use this info for any motor swap/ bike purchasing decisions!~~~
(it will save you future $$$ & headaches!)

As you may already know I have a 96 YZ80 in my YSR80...
Well I am here to talk about the SIRIUS VIBRATION PROBLEM!

Today I went for a ride, about 20 miles: My ignition tumbler broke in half , then fell out. Also the rear brake bolt vibrated off & i lost all rear brakes. (yes it had a lock nut on it) Same thing with one of the turn signals, but the wiring kept it from falling off. Several other bolts came loose too.
This is not to mention all the extra heat caused by the vibration!

So I have to recommend to anyone wanting a steerable YSR,
DO NOT use a YZ, DT, KX, CR, RM, etc.. 2 stroke!!!!!!!!!!!!!!
The vibration is unbelievable!!!!! It will crack the frame, loosen lock nuts & bolts, brake ignitions, etc...
Yes the power is great, but DEFINITELY NOT WORTH ALL THE PROBLEMS.....

Thees motors may be great for racing, Just not the street!!!!

I would recommend using a well balanced larger 4 stroke (like a XR100, 200. TTR125, 230, etc... Thees motors run extremely smooth!
The XR200 & TTR230 have the same Torque & Horse Power as a lightly modded 80 to 85 cc 2 stroke.

[ysrcali]

WOW, don't know how I missed this thread!

Yes, the MX motors do vibrate like a mo fo! I too did an 80 swap during the mid 90's. In short, I too reverted back to a 50 :-(

The long......

Altho', by rubber mounting several areas of the bike, I was able to minimize the vibration to a tolerable level where I was able to ride long distance, without numbing body parts *cry*

However, because of the type of motor I used, KX80, the exhaust is "spring" held against the cylinder. The vibration from the motor soon took it's toll on the frankein pipe I had used for my conversion (modified Toomy 50 pipe). Back then, I didn't have the resources I do today. I probably could have gotten away with using the KX80 exhaust, but tossed it out when I began the project, and just didn't know any better....live and learn

I often pondered the thought of doing it again...because the power was so rewarding. Problem is, there are not many 80cc motors that have a lighting coil available.

So I did the next best thing, I installed the Derbi motor (Senda) and used a Metrakit 72cc "SP" kit. Yes, it may have been a little more out of pocket, but! I don't have to go through all the bs with an MX 80cc motor. Installing the Derbi motor is one of the best upgrades I have done to the YSR. I can now ride long distance, and at top speed, without ever worring about seizing the top-end.

Btw, I do have an w/c 04 NSR motor w/ exhaust, up for sale if anyone is interested in the swap email [e-mail] if interested