1976 Suzuki ts125

[prandalljackson]

On the oil pump, if you are going to keep the bike original, keep the oil system as is. If you want to race it in vintage class, there is a shim washer that canbreplacr the oil guide plate. Look on a parts diagram for crank from a RM125 M. That was the first Suzuki that came from the factory without oil injection. Remove the oil guide plate and replace it with the shim. You will have to split the cases to do this. On the shifting, first think to look for is a bent shift fork. Thus will also require you to split the cases.

[motoxvet]

Good tip on the shim for the RM.  Correct that you can't just pull that guide plate out and re-assemble.  If I did my 250, I'd probably put it on a lathe and modify it - but that's just me....

[Weezer the Geezer]

At $100 you can't go wrong.  Why did you say the carb needs repair?  Is it idling too fast?  If so, it may need crank seals replaced.  Bad seals, (or cylinder gasket, or a carb to cylinder mount leaking) allow air to come in, instead of all through the carb, therefore a fast idle you can't control.  The crank seal on the left only draws in air, the one on the right draws air AND oil from the tranny, causing the engine to smoke more than usual.  I almost ruined a trans because didn't realize the oil had been sucked out.  I had noticed it was smoking a lot, but thought it was due to a different oil I was using.  If you have to split the case to work on the tranny, BE SURE to replace the seals while it is apart.  ENJOY!

[XR600allday]

Update: been working on it for awhile today. Cleaned the carbs, cleaned the point contacts. Haven't tried to fix first gear yet because I have never done engine work like that so I am hesitant. But I can't get it to run right it won't hold an idle but you can keep it running if you play with the throttle. It almost seems like it might be running rich? I'm not sure. Maybe it is a timing issue? I will try to put a video on soon.

[thejunkman]

Did you re-set the carburetor to factory settings (you have a service manual right)?  Use those as your baseline.

[XR600allday]

I reset it to what it was at 1 and 1/2 turns but I will check the settings.

[Weezer the Geezer]

If it is dying, the idle SPEED is probably set too low. Try adjusting idle speed 1st.  Would likey not be the crank seals, as that causes idle too fast.  Also, the 1 and 1/2 turns is an initial setting for the idle MIXTURE.  The final setting is done with a warm engine, idle speed adjusted, then do the final idle MIXTURE setting.  I have found the 1 and 1/2 turns on the mixture setting is not always the optimum final setting with a warm engine. All of this is assuming the carb is in good working condition and floats set correctly.

 

Also, when you cleaned the points, did you re-check the point gap?  Not enough gap will cause slow timming.  So make sure the gap is correct before adjusting the timing, which actually seldom needs adjusting unless some one has messed with it.

Edited July 17, 2015 by Weezer the Geezer

[thejunkman]

I reset it to what it was at 1 and 1/2 turns but I will check the settings.

 

I meant the whole carburetor, jets, needle clip position, float height, everything.

Edited July 17, 2015 by thejunkman

[XR600allday]

Haven't been able to really work on it yet but here are some more pics. If you wanted to see the bike.

[Weezer the Geezer]

Looks like it has good potential.  Enjoy!

[XR600allday]

I haven't got the owners manual yet and the bike needs a new spark plug it had a NGK br8es in it but had some washers on it so I don't think it is the right plug. I had googled what it should be and found a NGK b7hs. I was wondering if anyone could confirm this or maybe what plug you have used?

[XR600allday]

Well I put in the new spark plug in it ran much better not perfect but not bad. Drove it a little and got it into first gear somehow, I think when I was in 2nd I shifted down into first. But can't really get it back into first so I'm going to tear the motor down soon and find out what's wrong. Any advice would be awesome, thanks.

[XR600allday]

Next update: tore off the head and looked ok the took part of the case off and found a bunch of metal shavings and a nut and washer were off and sitting in the bottom here are some pics. this was the washer and it fit on the gear in the back. Going to work on it more tomorrow.

[motoxvet]

Good thing you found that before it even got worse.  Of course you know shavings are going to be in the entire gearbox.  You've

 got your work cut out for ya

[XR600allday]

Update: well I split the case and found more metal shavings but have no idea where or what they are coming from. Put the shift lever back on and shifted it through all the gears 1-5 and neutral. Nothing I can tell is wrong. My only explanation is that it had almost no oil in it so maybe a combination of metal shavings and the little oil was jamming it up? But that still doesn't explain the shavings. Except I can tell the motor has been taken apart because one of the studs on the head has been replaced. Maybe the person who had it apart left the shavings from something else? I don't know but I am hesitant to put it back together blaming it on lack of oil and after its back together it isn't fixed. Well that's what I know so far pictures tomorrow maybe you guys have some insight, thanks.

[Weezer the Geezer]

Are the shift forks worn?  If so, that could keep it from going into 1st all the time.  If they are okay, and you have got all the shavings out, It may be ready to go back together.  I forgot if we mentioned replacing the crank seals while you are in there.  A very good idea while you have it apart.