[nadroj]

Is anyone actually using the rear lower motor mount on the xr100 motor. should I go ahead and put them on (it is going to be a lot of work)

Here is my problem:

I am using the ysr50 front mounts but turned upwards 1/4 and using spacers with the xr100 front mount turned upside down. One of my mounts would spin around freely so I welded it together.

I test rode the bike and the square peg/bolt that goes into the actual frame turned and cracked the tab that it mounts on.

My plan is to fix the crack (weld it) then weld the peg on to the tab so it should not move. Do you think that will be solid enough to run with out the xr100 lower rear mount?

We are planning on racing this thing should I just go ahead and make the lower rear mounts? I really do not want to but I'd hate to brake the frame while we are doing an endurance race.

We are racing this weekend so I need to figure it out asap!!!

 

[PocketBikeRacingTsmmr]

From what I've seen road racing against these bikes,the stronger the motor sits in the frame the better ..seen way to many people on the sideline with motor to frame issues.

 

[nadroj]

From what I've seen road racing against these bikes,the stronger the motor sits in the frame the better ..seen way to many people on the sideline with motor to frame issues.

Are you talking specifically about people who are running the xr100 in the ysr or just in general? Do you know if any were running the lower rear mount. Based on that I think I will go ahead and cut the tabs off of the xr100 frame and weld them on. the front mount on the ysr is kind of weak.

 

[Luckystar64]

I'd hate to say it, but you might be better off in the long run working with an NSR50 rather than the YSR. Quazzymoto Brian has some brackets that will bolt the XR motor right into the chassis. If you get an NSR50 for $1500, and sell the stock motor for $500, then grab up the brackets-- you'll be alot better off than tring to mod up the old YSR chassis. Better everything on the Honda. --L*64

 

[nadroj]

I'd hate to say it, but you might be better off in the long run working with an NSR50 rather than the YSR. Quazzymoto Brian has some brackets that will bolt the XR motor right into the chassis. If you get an NSR50 for $1500, and sell the stock motor for $500, then grab up the brackets-- you'll be alot better off than tring to mod up the old YSR chassis. Better everything on the Honda. --L*64

I know we would definitely be better off with an NSR. But we have had the YSR sitting around with no motor, and I was able to pick up an xr100 motor for very cheap. So we are running the ysr. I agree though, nsr is better but this is for fun and we didn't want to put much money in it.

 

[PocketBikeRacingTsmmr]

Yes I'm specifically taking about racing against YSRs with XR100 motors but in them ..

 

[nadroj]

Yes I'm specifically taking about racing against YSRs with XR100 motors but in them ..

Great, thanks for the advice. What I have done so far is:

Welded up the YSR mounts so the bushings cannot move. Fixed the crack and welded that pin that goes through the ysr mount to the frame.

I did ride it after this and it felt pretty solid. But tonight I think I will go ahead and do the lower rear mounts, I have a trash xr100 frame so I will just cut the tabs off of it and weld them up. Unfortunately that is going to be kind of a pain because of where they are and that I am going to need to leave the motor in to make sure the spacing is correct.

 

[PocketBikeRacingTsmmr]

Good luck .lmk how it turns out..

 

[pheej]

ever considered a yz80 motor or simply didn't want to premix? would've done less mod/welding unless the stock ysr cradle needed it.

 

[Luckystar64]

Ya, and older air cooled YZ80 motor should just drop right in from what I remember. --L*64

 

[PocketBikeRacingTsmmr]

Though I am racing against YSRs via my NSR 50 here is an older picture of me chasing around a YSR with Xr100 motor..

 

[nadroj]

ever considered a yz80 motor or simply didn't want to premix? would've done less mod/welding unless the stock ysr cradle needed it.

Only the OLD air cooled yz80 motor fits with no cutting/welding I had one it was a turd, my carb actually broke and could never find a new one.

Ya, and older air cooled YZ80 motor should just drop right in from what I remember. --L*64

Yes they do but they are not very powerful it would have put us into a class where the yz80 air cooled motor is too slow and not competitive.

Good luck .lmk how it turns out..

It worked out GREAT motor mounts didn't break! We had only 3 problems, in the first 30 min I lost the clutch lever LOL I wasn't going to come in just because of that! Then my weld on the exhaust broken (I am maybe an hr into the race). Then when I am about to come in (1hr 30 min) the motor starts to loose power . I sent my brother out for as many laps as he could do, the bike had no power at this point. He came in after about an hour, I come out of pits and the motor dies!

Turns out the intake valve's clearance adjuster had backed out and when I got on the bike it finally popped out. Luckily it was sitting right in the head and I was able to scoop it out with a magnet!!

So all in all the bike preformed awesome I really should have just checked the valve clearance before we started racing, I would have noticed that the adjuster for clearance was not tight.