Suzuki ts 400

Bon Scott · 03-05-2013, 03:43 PM

Hi, I have a suzuki ts a 400 1976, and I am not happy.
The question is , is the bike fundamentally flawed or although I think I've tried everything is there a fix , that I haven't.

List :
Rings
Crank seals
2 x carburettors rebuilt
Burnt out exhaust
CID checked
Points and timing
The bike looks very original, but won't run clean top end and misses on quarter throttle.
Any help would be appreciated.

Cheers rob

wfopete · 03-11-2013, 05:00 AM

I have one too. Ran better than yours. Are you running premix or injector lube? I just keep with the injector because to bypass it is a hassle. Mine didn't run great but it got the job done. Terrible fuel mileage and the motor ran all over the place from decent to crappy.

mudgepondexpress · 03-12-2013, 07:31 AM

Does it stutter on the top end or does is feel fat? Sounds like you need to do some jetting to me. I don't think I have ever seen a 70's 2 stroke from Japan that wasn't overjetted from the factory. If you haven't tried it yet, pick up 1 richer and 1 leaner main jet. Start with the richer (bigger) jet and see if it makes it worse or better, my bet is it will be much worse. If I am correct, go to the 1 step leaner and keep going until it runs out clean.

Once you have the main jet dialed in, then go to work on the pilot and/or needle. I would work the same system on the pilot and see how it affects the bike, then work from there.

Yes, you will have a handful of jets when you are done, but it will feel good when it runs correctly. You will also learn how to pull the carb quicly and how little you need to disconnect to do it. I became quite good at the parking lot pull...leave the fuel line and throttle hooked up, loosen the carb, put a rag under it, pull it out far enough to remove the bowl and replace the jet. All told I could do a Yamaha DT in less than 5 minutes, a XR650L in roughly 8 (by leaving off those ugly scoops).

If the bike is not consistant in its running...sometimes good, sometimes bad, you will need to look at the spark advance system to see if it is operating correctly. I believe this was a common issue to the big ts/tm series (though this is from memory...they could have fixed it by 76).

Kenny

Aah5 · 03-13-2013, 03:48 AM

I had TS400-K back in '75/76 when working at Suzuki dealer, bike was a tradein that had was absolutely gutless 80 kph/50 mph tops.
Picked it up at our traded price and proceeded to make it run properly. Opened up the air box intake vents, rejetted carby, burnt out the exhaust carbon, decoked the exhaust port etc.
Anyway after a lot a fussing around, mainly jetting, in the end I had a TS that was capable of a genuine 160kph/100mph, had a flat torque curve and was an absolute blast to ride on the street not so good on the trails.
Persist with jetting and make it breathe better.

03-05-2013, 03:43 PM	#1
Bon Scott ^OP n00b Joined: Feb 2013 Location: Torquay England Oddometer: 1	Suzuki ts 400 Hi, I have a suzuki ts a 400 1976, and I am not happy. The question is , is the bike fundamentally flawed or although I think I've tried everything is there a fix , that I haven't. List : Rings Crank seals 2 x carburettors rebuilt Burnt out exhaust CID checked Points and timing The bike looks very original, but won't run clean top end and misses on quarter throttle. Any help would be appreciated. Cheers rob

03-11-2013, 05:00 AM	#2
wfopete Suffer Fools; Gladly! Joined: Aug 2004 Location: Somewhere North of Dover, AR Oddometer: 309	I have one too. Ran better than yours. Are you running premix or injector lube? I just keep with the injector because to bypass it is a hassle. Mine didn't run great but it got the job done. Terrible fuel mileage and the motor ran all over the place from decent to crappy. __________________ *Suffer Fools; Gladly!*

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03-12-2013, 07:31 AM	#3
mudgepondexpress Beastly Adventurer Joined: Jan 2007 Location: Spokane, WA Oddometer: 1,108	Does it stutter on the top end or does is feel fat? Sounds like you need to do some jetting to me. I don't think I have ever seen a 70's 2 stroke from Japan that wasn't overjetted from the factory. If you haven't tried it yet, pick up 1 richer and 1 leaner main jet. Start with the richer (bigger) jet and see if it makes it worse or better, my bet is it will be much worse. If I am correct, go to the 1 step leaner and keep going until it runs out clean. Once you have the main jet dialed in, then go to work on the pilot and/or needle. I would work the same system on the pilot and see how it affects the bike, then work from there. Yes, you will have a handful of jets when you are done, but it will feel good when it runs correctly. You will also learn how to pull the carb quicly and how little you need to disconnect to do it. I became quite good at the parking lot pull...leave the fuel line and throttle hooked up, loosen the carb, put a rag under it, pull it out far enough to remove the bowl and replace the jet. All told I could do a Yamaha DT in less than 5 minutes, a XR650L in roughly 8 (by leaving off those ugly scoops). If the bike is not consistant in its running...sometimes good, sometimes bad, you will need to look at the spark advance system to see if it is operating correctly. I believe this was a common issue to the big ts/tm series (though this is from memory...they could have fixed it by 76). Kenny

03-13-2013, 03:48 AM	#4
Aah5 russ Joined: Feb 2009 Location: Brisbane,Australia Oddometer: 53	I had TS400-K back in '75/76 when working at Suzuki dealer, bike was a tradein that had was absolutely gutless 80 kph/50 mph tops. Picked it up at our traded price and proceeded to make it run properly. Opened up the air box intake vents, rejetted carby, burnt out the exhaust carbon, decoked the exhaust port etc. Anyway after a lot a fussing around, mainly jetting, in the end I had a TS that was capable of a genuine 160kph/100mph, had a flat torque curve and was an absolute blast to ride on the street not so good on the trails. Persist with jetting and make it breathe better.