TS50X won't rev past 7k

richardk · L Plate Warrior Joined: 31 Jul 2009 Karma :

Hi, my lad and I have been rebuilding an old ts50x for the last year, it was in a bit of a poor state to say the least but this is how my dad taught me so wanted to pass this knowledge on.

It has put up a right battle but we're nearly there which is good as he's got his cbt on Sunday.

We've been out practising on some private land and I've been riding it about and notice it won't rev past 7k but seems to be doing the correct speed about 35 / 40mph at about 6 / 7k. I have checked the rev counter with another and it reads the same.

I didn't check the oil pump drive when we first put it together and it promptly seized the piston, after a rebore and new piston it sounds loverly but the oil pump pinion gear must have lost a tooth as the drive gets to a certain point and then stops, why Mr Suzuki decided to put a plastic gear in the gearbox I really don't know, anyway she's on premix at 40:1 which seems the run great, nice and clean. I had an old engine and I did split it to see how hard a job it was to change this gear and its a right pia, hence the premix!!

Pretty sure the mixture and carburation is spot on.

Could this problem be the ignition, not advancing properly, how does it advance the ignition? Have read the book of lies but it doesn't explain how it advances Crying or Very sad

Looks as though a special puller is required too Crying or Very sad

Sorry for the long post but here are some before and after pictures of our work. Nice to put an old bike back on the road but more importantly I KNOW it's safe for my boy Cool

https://www.kilmartin.it/uploads/ts50x/old.jpg
https://www.kilmartin.it/uploads/ts50x/now.jpg

Cheers

Rich

P.S I know the front tyre looks as though it on the wrong way round! Buts it right, honest!!

bladerunner · World Chat Champion Joined: 09 Sep 2006 Karma :

If your running a std suzuki exhaust then that wont let it rev much. Very flat easy torque curve with no top end pep. some of the later ones have a restrictor in the header pipe but if you want it to rev higher then it's new front pipe time. something along the lines of BIG ONE etc let it rev to about 9K (making peak power at about 8-8.5K). Also fitting one of the cast iron big bores with the bolt on crank case reed cage makes a huge difference to these little suzukis. with a bit of gearing up they will hit 60mph on the flat and 45 up the hills. I worked on one for a year.And we got some pretty good power out of it whilst still being very reliable. (he even ran it for a couple of months on gearbox oil!!!!!!! you should have seen the build up of deposits the detergent left on the plug Sick

) talk about run it on pocket money!!!

As for the timing it does seem to run out of advance quite early but as this bike was used for day to day transport I never got round to playing with the timing I was tempted to shave a mm off the woodruff key to give it a few degrees more advance but given it was on a std carb and air cooled thought best to leave it as was.
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Current bikes...cbr929, KDX200's, Rd125lc mk2, RGV250's

richardk · L Plate Warrior Joined: 31 Jul 2009 Karma :

Thanks for that, so with a standard exhaust on it, is it normal for it not to rev past 7k in any gear? Clocks say 10 - 12 redline so was expecting to be able to briefly rev it a bit higher than 7k.

Going to check the timing as I've read if I have loads of advance then this will happen see here https://newsgroups.derkeiler.com/Archive/Rec/rec.motorcycles.tech/2006-03/msg00297.html

Thanks for the reply, much appreciated.

Cheers

Rich

bladerunner · World Chat Champion Joined: 09 Sep 2006 Karma :

Yes the red line is what the motor is able to rev to in full power trim as some of the continental models are capable of I think are making near on 8-9bhp not the 2.8 or so the restricted ones do. with the std exhaust your not going to gain much in the way of benefit from changing the timing and it's not easy to adjust so until you get the pipe changed and maybe the big bore ( wont bother a well set up motor as it still wont rev as high as the tuned 50 and makes about the same bhp). If you want info on the results we had over a years chioping and changing..ie which kit to get etc then drop me a P.M.
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Current bikes...cbr929, KDX200's, Rd125lc mk2, RGV250's

richardk · L Plate Warrior Joined: 31 Jul 2009 Karma :

Thats great, so basically he'll not be able to over rev it Very Happy

Thanks very much for the advice, I will drop you a pm asking for your trial and error settings, especially the gearing you've ended up with as I reckon it could easily take a couple of teeth more on the front and maybe 1 less on the back.

Thanks again for your help.

Cheers

Rich

Blue_SV650S · World Chat Champion Joined: 27 Nov 2008 Karma :

If you have a welder and are brave, you can chop open the front pipe and de-restrict it!! Thumbs Up

p.s. my first ever road bike was a 87 TS50X and I loved it to bits!! Thumbs Up

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The purpose of life is to fight maturity.

richardk · L Plate Warrior Joined: 31 Jul 2009 Karma :

Mine was too, enjoyed doing this one up as well. Do you happen to know where the baffles are in the front pipe? Done a picture with numbers added which may help identify the location.

Cheers Rich

https://www.kilmartin.it/uploads/ts50x/muffler.gif
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UNDERSTEER is when you hit the wall with the front of the car. OVERSTEER is when you hit the wall with the rear of the car. HORSEPOWER is how fast you hit the wall. TORQUE is how far you take the wall with you. Build pictures can be found here, https://www.kilmartin.it/cgi-bin/gallery

mr rip · Scooby Slapper Joined: 24 Jun 2009 Karma :

I've had quite a lot of these over the years

that picture looks more like the the ts 50 er, but no matter, if you take the exhaust off & look at the back/inside edge just rearwards of point 10 you should see two vertical lines of spot welds those are the plates you are after

if you cut vertically between those two sets of spot welds you will see two plates (one in each half) the one closest to the engine will have a large hole in it & the one on the other side will have a small hole

the best method I have found for tuning these exhausts is not to take them out completely, but to get a 5 or 6mm drill & drill lots of holes all around the plate so it looks like a cullendar

I've removed these plates completely befor now but it worked better when I just followed the above method

you will also be wanting a decent tail piece to make full use of the exhaust modification, as the standard suzuki one will strangle it a bit, & don't forget to up jet the carb to suit
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never criticise a man until you've walked a mile in his shoes, then when the muck hits the fan you'll be a mile away & you'll have his shoes

richardk · L Plate Warrior Joined: 31 Jul 2009 Karma :

Thanks for that, do you mean drill loads of holes in the plate with the small hole or both plates?

Cheers

Rich
____________________
UNDERSTEER is when you hit the wall with the front of the car. OVERSTEER is when you hit the wall with the rear of the car. HORSEPOWER is how fast you hit the wall. TORQUE is how far you take the wall with you. Build pictures can be found here, https://www.kilmartin.it/cgi-bin/gallery

mr rip · Scooby Slapper Joined: 24 Jun 2009 Karma :

ah sorry,

yes drill lots of holes in both plates
____________________
never criticise a man until you've walked a mile in his shoes, then when the muck hits the fan you'll be a mile away & you'll have his shoes

richardk · L Plate Warrior Joined: 31 Jul 2009 Karma :

Nice one, thanks fella.

Cheers

Rich
____________________
UNDERSTEER is when you hit the wall with the front of the car. OVERSTEER is when you hit the wall with the rear of the car. HORSEPOWER is how fast you hit the wall. TORQUE is how far you take the wall with you. Build pictures can be found here, https://www.kilmartin.it/cgi-bin/gallery