TS250 engine problem

[Joe Blogs]

Hey everybody,

On my 1972 Suzuki Ts 250 it runs fine at idle but when u ride it if u go from no throttle to Full throttle or even half to full it bogs down, almost dies and I think its flooding it does it in all gears 1,2,3,4,5. I usually just give it half revs and it runs fine but when u keep it a half the speed slowly builds up and runs at full revs but if u give it full throttle it bogs down so i just give it half and ride it and it starts to pick up speed. But its really annoying when i try to race my mate i give it full throttle and it bogs down and my mates already finished the race so any help will be good. My Bike is 1.0 mm overbore, I just want it so if i give it full throttle if doesn't bog down or flood and just goes like a normal bike

Thanks a lot
JB

[MSTRS]

Filthy air filter? Worn-out jets? Coked-up exhaust port?

[Joe Blogs]

Air filter is good, how do I check if jets are stuffed?

[MSTRS]

A workshop manual, a selection of appropriate tools and some nous. Or find someone who can.

[merv]

Could even be crud in the main jet so that it just doesn't like it when you open the throttle. Take the bottom off the carb and unscrew the jet and have a look.

[Joe Blogs]

Had jet checked out, seems to be fine, checked that flotes were closing off fuel inlet into bowl and it is, exhaust port had some carbon build up but not much and didn't make a difference when cleaned out. Any ideas of what else it could be?

Thanks
JB

[MSTRS]

2 strokes eat plugs. But you knew that. New one in, anyway. OK?
Maybe the coil is on the fritz?

[Yow Ling]

Go for a ride and take a plug spanner with you , try and ride it at full throttle or 3/4 throttle for a while then stop the engine and pull out the plug have a look and see if it is wet , oily or a nice choclate coffee colour . this is the most basic check you can do , we cant tell from here if the bike is rich or lean, even better take a photo of the business end of the plug and post it up then you will make some progress

[ypvs kiwi]

Hi Mate - check tank breather is clear - sounds more like a fuel issue than electrical.

Cheers.

[Joe Blogs]

Been doing some work on the bike as I had some free time.

Plug is black,

Have burnt carbon out of pipe, can taken head off and cleaned carbon off piston top and combustion camber on head.

Still isn't running right.

Any suggestions?

Does anyone know ruffly how many omes of resistance there should be going from secondary coil to spark plug cap??

Thanks
JB

[MSTRS]

Plug is black,



Bike is too rich on an open throttle. The choke butterfly is staying fully open?

[Joe Blogs]

Choke is fully closing.

Could the problem be CDI? - Its not points

Cheers
Jb

[Jantar]

Choke is fully closing.

Could the problem be CDI? - Its not points

Cheers
Jb
Are you sure its a 1972 (J) model? IIRC CDI wasn't introduced into the TS250 until the 1975 (M) model. Prior to that it was magneto. The TS185 was the first to go CDI in 1973 or 1974.

However I would agree that it sounds more like a carb issue than electrical. I no longer own that particular manual to be able to read off all the settings, but some possible causes are the float set to low. ie. its closing off allright, but with too much fuel in the bowl; The needle is set too high so that its allowing too much fuel through as the throttle is opened; maybe someone in the past has fitted a non standard slide with the wrong cutout angle on the face.

Has this fault just suddenly developed, or did it start
as an intermittent fault?

[Joe Blogs]

Im not sure, its my dads bike, he never rides it and I hadn't really ridden it for about 3 years, took it out about a year ago for first time and it was running bad then and hasn't improved but I dont think it has gotten any worse either.

On the motor it has stamped TS2503 - 64839 dont know if that will tell you the model.

I have the fly wheel off at moment and there are def no points in there, just coils.

Slide is factory - dad has owned it since about 1974

[MSTRS]

Choke is fully closing.



I meant 'open'...the butterfly flap should be horizontal in the throat of the carb when the choke lever is 'off'. If the operation is a bit loose, then the extra suck caused by a fully open throttle can pull the choke flap (toward) closed, which restricts the airflow and makes it too rich.
Another thing...old bike, original carb etc... The needle and/or the mainjet could be getting worn. It the needle has a choice of groove rings at the top with a circlip in one of them (sets the needle position in the slide and stops the needle falling out the bottom :lol: ) you could try moving the circlip to the groove just above the one currently in use. That will lean out the fuel flow a bit.

[Joe Blogs]

Will try leaning out tomorrow, as for the choke it doesn't have a butterfly it is like a round shaft with a seal on the bottom that goes up when you put the choke on and lets extra fuel into the carb from the bowl, I am guessing this is how carbs were before butterfly's.

A friend thinks he has a carb the same that I could try some parts from to see if i can get a fix.

Does anyone know what the resistance of my coils should be?

[nsrpaul]

orange is the new black:headbang:

[Joe Blogs]

Have now tested bike with a 140, 150, and a 170 main jet (180 was in it)

Bike still fails to run right and none of the jets seemed to make it run any better.

I have also discovered if I keep the throttle fully open the bike will bog and die.

Any body have some ideas?

[eelracing]

Maybe gearbox side crank seal is perished and sucking in the oil.Could explain the black plug.

[geoffm]

Does it flood if the bike is sitting - could be the float valve is foobared and hence letting to much gas through, so it will be rich.

[Joe Blogs]

Checked seal by spraying crc to see if idle increase, they didn't.

And floats are all good, got checked by bike shop, doesn't flood at idle, dies if u don't give it any revs for about 15 seconds.

Any more ideas?

Does anyone have a wiring diagram?

[SS90]

Checked seal by spraying crc to see if idle increase, they didn't.

And floats are all good, got checked by bike shop, doesn't flood at idle, dies if u don't give it any revs for about 15 seconds.

Any more ideas?

Does anyone have a wiring diagram?

I think he means the gearbox side seal (you can't test that by spraying crc onto it....it's behind the front primary gear under the clutch cover), the only way to test it is by "leak down test", or simply pulling the clutch off and replacing the seal.......

With your black plug (gear box oil possibly getting sucked through the seal, causing the black plug).

It could be the problem.