79' tf125 power band???

[Dirty DR]

We hav just fitted an old tf125 engine to a later model TS frame but the motor doesnt seem to have a noticeable power band. Is this normal? Comparing it to my AG175 which has quite a noticable pull when it hits its rev range, the tf feels like a 4 stroke. if its not normal wot could be the cause of its sluggihness? thanks in advance

[Motu]

Missing 50cc?

[xwhatsit]

The power band may have snapped. It is a 1979 model, after all, and I'd be willing to bet that it's never been replaced in it's entire life. Being a Suzuki, it probably perished anyway.

You may be able to find a replacement power band from a Honda wreckers -- I hear the NSR250 has a very strong power band.

[Skunk]

Has it got the right pipe and carb setup?

[Dirty DR]

Has it got the right pipe and carb setup?

it has the standard carb and exhaust\expansion chamber on it.

[MSTRS:Me]

The TF (AKA Mudbug) was designed as a farmbike primarily, so engine design etc was intended to give reasonable 'pull' at any revs. Therefore, the powerband normally associated with 2-strokes is sadly missing. In saying that, it is possible to achieve an improvement with a better expansion chamber and some port work.

[Pwalo]

From memories of my TS125 it didn't exactly have what you'd call a power band.

Didn't the TFs run a high/low ratio gear box as well?

If your engine is in good shape you can always try the pipe and carby route, but it might be cheaper to source a later model 125 or 185 motor.

[stanko]

TFs have got tiny inlet ports , TS is the same basic motor with better ports. With good porting and a pipe to match this can be a wicked engine with around 18hp. They are a pretty common bucket racing engine. Maybe 7 or 8 hp stock though

[Dirty DR]

thanks for the replies guys, that was basically what i was wanting to kno that due to its farm design.
I cut the expasion chamber in half the other day to make sure it wasnt blocked and in the back half of the chamber theres 2 partition like plates, the 1st having a maybe 50mm hole and the 2nd a 30mm hole in the centre of each plate. my very limited knowlege of 2 strokes is that the power band depends on the shape n position(among other things) of the expansion chamber but i didnt expect to see these baffle things in there. would cuting them out make a difference? thanks again
and forgive my ignorence, im new to bikes.

[TonyB]

What MSTRS said- they were designed to have a wide spread of torque, especially at low revs, so they won't have a sudden inrease in power like you get in a more sporty bike.

As for the plates, are they in the expansion chamber or in the muffler on the end? If they're in the muffler- that sounds pretty normal. I can't imagine why they'd be in the expansion chamber- or why Suzuki would go to all the trouble of shaping the expansion chamber only to bugger it up by putting plates in it. Unless of course they were trying to 'detune' an expansion chamber that was used on several models. Then again, a sudden change in the expansion chamber should give it a sudden change in power at some point of the rev range... unless it's positioned in the right spots.....Confused yet?

[MSTRS:Me]

From memories of my TS125 it didn't exactly have what you'd call a power band.

Didn't the TFs run a high/low ratio gear box as well?

The TS did have a powerband, although not earth-shattering. (at least mine did in 1973)
The TF was just a really detuned TS. The hi-lo ratio was the TC.

[Skunk]

I have a TF125 in pieces under my bench... Must put it in something one day.