Some experienced help needed!?

Question

Well, my bike wont start now after ive re-built it and basically all i need is a list of possible problems/solutions.

Here are some details.

Bike: 1980 Suzuki TS
Starting Method: Kick-Start
Ignition Deatails: Magneto/stator plate, contact breaker points.
I have got a good spark.
There is fuel reaching the spark plug.

But still nothing? Another thing is, the bike doesnt even sound like it wants to start?

Any help much appreciated!!! Thank you!

Answer 1

OK, you need real help. So - try these steps. I know they work, been doing this stuff over 50 years, no guessing or maybes here.

I am assuming you did a proper job on the rebuild. Valves, either new or good, are lapped to head and have a good even seat in head and on valve. Valves are properly adjusted, clearance to proper spec, if you do not have a manual which says different, with intake fully open, adjust exhaust, exhaust fully open, adjust intake. Piston ring end gap is correct, and gaps spaced apart pn piston when installed.


1. Take plug out, insert it in plug wire, lay it on cylinder head, out of harms way. Place finger or thumb over plug hole, and kick engine over. Any compression? If you have compression, get a compression guage, screw it in plug hole, or if a rubber tip type, get some one to hold it. Open throttle wide, kick hard. Should have at least 100 psi. If so, move on. I

2. If first test passed, take a good spark plug, does not have to be new, but must be clean. Break the ground electrode off. Put in plug wire, lay on head, and give it a good kick..Spark should jump from center electrode to body of plug. Remember, it takes a lot more spark to jump a normal gap with 100 psi or more compression, so this is the proper way to prove you have enough. If this passes, go to # 3.

3. OK, so we now know you have compression and fire. Did you have the point plate off the engine? Did you put it back at the right place. Most of these engines fire as well at the bottom of the stroke as at top, but of course, the engine does not run. The magneto should have timing marks, so take a piece of hard cellophane, like a cig. pack wrapper, or such (Hope you do not use these otherwise). Cut it into a strip, 3/8" wide or so, 2 in or so long. Carefully insert it between the closed points. Tug lightly on the cellophane, and turn the engine forward with your hand. Note where the cellophane is released. This is the firing point. The mark on the rotor should be at the fire mark on the engine. If not, rotate the point plate until it is there.

4. You said it get fuel, maybe too much? If the first 3 items did not get up going, maybe flooding. Is spark plug wet with gas? Has carb been cleaned, adjusted, according to spec?
Is the spark plug new/clean. If the insulator has a coat of carbon, it may fire in open air, but not under compression. Is the gas fresh, or been in the tank for a long while? If it has, drain, flush, and refill with fresh gas. Also, it is possible fuel has drained down into the crankcase, which will wet the plug immediately.

If these steps do not get you going, you may E-mail me with more details, and I will see what else I can find for you.

Tomcotexas

[e-mail]

Answer 2

if it is a 2 stroker ( as most TS were) does it have a rotary valve engine with the carb on the crank or does it have the carb on the cylinder block.
is it sucking air into the engine.?
If it isn't sucking air into the engine through the carb then you could have:
1. put the piston on back to front ( little arrow on top faces forward)
2. installed the reed block back to front, or omitted it completely
3. failed to install the gaskets and get gas tight seal between components.
4. broken the piston rings when putting the engine together ( lack of compression when turning over too)

do wet and dry compression tests to check engine health, engine should have between 100 and 150 psi from the spark plug hole.
Without this it aint going to start.

Check ignition points open as the piston reaches the top of it's stroke and closes just after, if not either the points or the mag flywheel are on the wrong way (TS Suzukis were renowned ) shearing the luff key on the crank shaft causes the flywheel and therefore the timing to slip considerably.
Check throttle slide action.. It should drop to the bottom of the carb body and the needle should enter fully into the main jet. this could be 180 degrees out and therefore the carb is almost fully open all the time and the engine is too lean to start.
Check also that fuel does get to the float chamber and doesn't run out of the carb, if so then float heights need adjusting cleaning.
Check all oil seals and joints for leaks.
Try ether based engine starting sprays to see if the engine will actually fire, but not to much as the adatives gum up the rings

OH and GOODLUCK

Answer 3

Always give year, make, "engine size" and model # when asking questions. We need all of that info to give an informed answer.
The TS model came in 4 sizes.
First check that the carb is clean.
Remove the pilot jet (long and thin) and hold it up to the light.
You should be able to see through it.

The crankcase could be flooded.
Remove the spark plug (DO NOT insert it into the spark plug cap).
Turn "off" the ignition switch (remove the key to make sure).
Put the bike in gear and push start it down the block.
While in gear, the piston will move up and down, blowing excess fuel out the spark plug hole.
With the crankcase flooded, to much fuel will get transfered to the combustion chamber and drown out the spark.
There will be to much fuel in the bottem end to be transfered in one stroke and the cycle repeats itself.
To much fuel - not all of it transfered - drown the spark - more fuel added to the bottom end - repeat.

Pull off the top end to make sure a ring didn't get snagged on a port.
You could have installed the piston backwards.
Check the reed valve while the cylinder is off.
Hold the reed block up to the light to make sure the reeds are making a perfect seal.
Did you install a new gasket on the reed block and clean all surfaces till they look brand new?
Same thing with the cylinder, crankcase and head.
They must look brand new, or the gaskets won't seal properly.

Answer 4

You need to go back to basics

You have spart and fuel so that rules those out

You now need to see if the combination of fuel and spark are at the right place at the right time

I would first re-check the valve timing even if you have done it a dozen times. Then check the ignition timing and check that the timing is on the correct cylinder. I know this sounds "very" basic but it is the only way to do it.

If you have the timing spot on but on the wrong cylinder it just won't go. The spark needs to be timed on the cylinder that is at TDC on compression

Once you have re-checked this. Dry the plugs and give it another go and good luck

Sorry to question your ability but sometimes we have to go right back. I have spent 40 year in the motor trade and you just sometimes get caught out

Answer 5

Hi ,remove the spark plug dribble a thimble sized amount of fresh petrol not two stroke into the cylinder replace plug as fast as poss then kick.If your bike fires suspect a carb/reed fault if it runs for say five seconds, If you get no firing suspect spark/ignition problem.It may be that you have to much oil residue after the rebuild

Answer 6

It takes three things to make an internal combustion engine run, Fuel, Ignition, and compression. You indicated you have fuel and spark so I suggest you check compression. If in fact you have compression, It will run, you may need to recheck the timing and ensure that it's sparking somewhere just after TDC. I'm not real familiar with this unit but I'm assuming that it's a two cycle and that you inspected the reed valve to ensure that it's not damaged and is seating properly and you've cleaned the exhaust port before reassembly.

Answer 7

Is this a 2-stroke single we're talking about?
Are you getting a nice strong blue spark?
Did you rebuild the carb?
Have you checked your timing?
Could be a fuel flow issue.
I dunno. Eliminate one thing at a time and see how it goes.

Answer 8

When you put it together did you line up your timing marks with your firing order sounds like your timing is way out .

Answer 9

Tomcotexas obviously knows his stuff. You can't go wrong taking that advice. He should write some guides.

Answer 10

ok i heard of a little trick u can use, it moght work then again might not. when u kick start and rev the engine on nuetral, try and kick the engine hard not to hard that u will break it but hard ebough gd luck