Ts/tf100

[Yow Ling]

wot did you decide to do in the end?

Borrow your TS100 bottom end?

Will pull it apart this weekend and clock the crank, maybe try another crank , maybe fit some plugs like Speedpro suggests

[Sketchy_Racer]

The question looming in my head is has that motor/bike claimed any more victims yet? I never did get on well with that bike and spent more time on my arse wondering what just happened!

[Yow Ling]

It claimed me at Nelson , then I replaced the rear shock which was the main problem. Got it some new forks brakes wheels etc Bren painted it and fitted a different engine Ill post a picture later

[Chambers]

It has a dark side It has wicked vibration about 5-6-7-8K (no tacho just guessing) then it comes smooth. this is the kind of vibration that turns your hands to jelly, im thinking the most likley suspect is the crank cant really be much else,

For what its worth. A picture of a TF and RM crank. Different balance factors.

TF on the left RM on the right.

.

[SHELRACING]

Whilst the experts are all here talking about vibration.

I had to reluctantly return the FXR motor I borrowed, and have just repowered the Delta with a Yamaha RX125 motor.

Had it running for the first time a couple of days ago and sorted the jetting. When I took it to the track for a few test laps. I had a similar vibration to the one described by Yow Ling. Right through the whole bike. making it difficult to ride.

I mounted the engine using the rear 2 mounts only and left the front mount off. I assumed it was an engine mount problem. Is it more likely to be a problem with the motor. Crank ? Bearings ? The motor sounds ok. with no undue noises. Come to think of it I have experienced vibration through an RX motor before, but not this bad

The bike is showing a lot of potential if I can get rid of the vibration.

[Korea]

It claimed me at Nelson , then I replaced the rear shock which was the main problem. Got it some new forks brakes wheels etc Bren painted it and fitted a different engine Ill post a picture later

Pictures man! Pictures!

[xwhatsit]

Not that I know shit, but I know when the top engine mount of my 250RS fell off (yes, it really did fall off, dunno where the hell it went), it began to vibrate like an absolute whore. So much so that other things started to vibrate off. Particularly about mid-range, but certainly lots more vibes throughout the whole range.

When I had the bike apart to do my steering head bearings last weekend, noticed the mount was missing and stole one from my spare chassis. It's now turbine-smooth again (well, as far as a single can be, but this engine is known for being pretty smooth).

So, anecdotally, maybe it's just an engine mount problem?

[speedpro]

Whilst the experts are all here talking about vibration.

I had to reluctantly return the FXR motor I borrowed, and have just repowered the Delta with a Yamaha RX125 motor.

Had it running for the first time a couple of days ago and sorted the jetting. When I took it to the track for a few test laps. I had a similar vibration to the one described by Yow Ling. Right through the whole bike. making it difficult to ride.

I mounted the engine using the rear 2 mounts only and left the front mount off. I assumed it was an engine mount problem. Is it more likely to be a problem with the motor. Crank ? Bearings ? The motor sounds ok. with no undue noises. Come to think of it I have experienced vibration through an RX motor before, but not this bad

The bike is showing a lot of potential if I can get rid of the vibration.

when I first fitted the TF engine to my RG50 chassis it vibrated REAL bad. I then made a better not so flexible front engine mount then it only vibrated bad. Then I rebalanced the crank and it didn't vibrate at all.

The front mount made a big differance. Without a good one it let the motor "start" vibrating then it just built up with revs.

[SHELRACING]

when I first fitted the TF engine to my RG50 chassis it vibrated REAL bad. I then made a better not so flexible front engine mount then it only vibrated bad. Then I rebalanced the crank and it didn't vibrate at all.

The front mount made a big differance. Without a good one it let the motor "start" vibrating then it just built up with revs.

Cheers speedpro, I remember your FZR / MB100 doesn't use a front engine mount. That's one reason I didn't bother. Do you notice any vibration through your FZR chassis.

I have removed the flywheel today, wondering if it will make a difference, but haven't run the motor yet. If that's no better I'll make up a front engine mount.

What is the method for checking and balancing the crank

[speedpro]

That MB bottom end is a bit different. I've removed the counter balancer which will make them vibe pretty badly, but, I rebalanced the crank to compensate. It does still vibrate but not too bad. At the moment I have no plans to change the balance factor again.
I doubt that removing the flywheel will affect vibration unless the rotor is unbalanced.
I actually did a "bit" of science to alter the balance on the MB but on my TS when I did it, all I did was note that it vibrated at high revs and therefore I had to reduce the counterbalance, which I did by pressing a slug of alloy into the larger hole in each crank wheel. Purely guesswork and a suck-it-and-see procedure. It just happened that it was pretty well spot-on. It'll be the same for all the motors we use as they are all being revved beyond the design intention. Remember as speed goes up the forces generated by the piston going up and down rise linearly but the forces generated by the crank rotating rise with a square law - 2X the speed & 4X the force. That's what you modify to rematch at higher revs.

[SHELRACING]

I'll just give the motor a quick run to see the difference with the flywheel off.

Looks like I'll be making an engine mount this weekend then. I have the basis for one already from the FXR motor, which incidently showed no vibrations at all. The trouble is the mount will end up being a bit heavy. I've dropped over 20kg changing the motor and was reluctant to put weight back on. Another reason for not making the front mount in the first place.

I have another gearbox/crank so I might pull it apart and take a look.

[SHELRACING]

Ran the bike yesterday and there was a big improvement throught the low - Mid range with the flywheel removed. Still vibrating through the top end but not so bad. Still going to make the front mount to see how that goes.

Running the motor with a YZ125 chamber, flywheel removed as well, motor feels very responsive. YZ chamber is awesome.

[Yow Ling]

I was sorting through some bits and pieces the other day and found this crank, seems sombody has already done the hard work and added the weights, just needs a rod kit and some bearings and we will be racing

[F5 Dave]

yeah you might consider running a wire brush over it as it looks like it was dredged from a sea wreck. Maybe some lapping paste for the flywheel or it will loosen (std flywheels should not be used if you intend to rev as they snap the crank end off, not sure if mentioned above). & autosol the seal surface of course.

So the later model 125 has the 6 speeder for some dumb reason.

[Yow Ling]

Yea its not super pretty is it. Maybe Ill run it under a cold tap. Ill get it back from the crankshaft guy tomorrow, pretty good service really I only took it in this afternoon. I think he feels sorry for me sometimes. It will get an early RM125 rotor on the end, and yea it does have the 6 speed although first is really not alot of good for anything.