Project bike won't start

I've had a lot of experience with no starts (30+years), but lately I've come across a new syndrome. This happened with my KZ 400, my Toyota Corolla, and my KOHLER two cylinder mower. In all 3 cases plugs were clean and dry, and I tested out a strong spark by grounding the plugs while cranking. In one case the plugs were brand new. I used ether, carb cleaner, and every trick in the book w/o luck. In desperation I replaced the plugs and the motors fired right up. I'd never seen this before, but now three times in 6 months. I'm guessing that maybe some film forms on the plugs from crappy ethanol gas causing them not to spark under compression? I don't know, but new plugs were the answer in all three cases. Worth a try, just my 2 cents.

[JTGS850GL]

You are using the "choke" on full, correct?

You said you are using a remote gas tank. Did you make sure to plug the vacuum line coming off carb #2?

I had the airbox on with the cover no air filter. I am going to get the valves adjusted correctly and start from the beginning. I think the bike is getting way to much air and if the intake valves are tight and getting pushed down more then they should that would cause the problem (i think). So once that gets properly adjusted I am going to try from the beginning and see what it does.

[hjfisk]

Have you got air filter, or pods on it? if not you may not get it to fire. You need to restrict the air alittle .

I read both bikecliff and that link as well as the manual and they basically all say the same thing. I hope by trying to turn it over I didn't bend a valve or something Otherwise I bought the valve tool and some starter shims so I can hopefully have all in spec in a couple weeks.

[Big T]

Ok so I did my valve clearence check based on this website: [url]http://guglielmo.us/mc/valve_clearances.htmlok.

That procedure appears to be incorrect. See the bike cliff link and find the 8V adjustment

Low compression is killing you here

[jsandidge]

Shims are not expensive. You likely won't need many, as you can swap them around as needed. There is a member here (GhostGs I believe) that runs a shim club. For a small donation, he will swap your unneeded shims for the sizes you require. I've even done this with my local dealer for free! The only real expense is a gasket and rubber half-moons. Since you've already removed your cover to check your clearances, you need them now anyway.

Ok so I did my valve clearence check based on this website: http://guglielmo.us/mc/valve_clearances.html

It appears that I do not have .04mm clearence in any cylinder I don't have a smaller feeler gauge so I don't know if it is touching or at .01-.03. But I do know that I am in for some serious shimming. But that is expensive and time consuming.

before I fork out the cash on that is there anyway to test the condition of the cylinders? Can I put the valve cover back on with a few bolts and do a compression test? I want to know that if I spend the money on shims that the rest of the bike is ok.

[tom203]

Make sure plug wires are on correct plug. From a cold start .,these bikes need an extra shot of fuel from enricher circuit ("choke")- yours are probably still gunked up. As mentioned,locate those old carb parts.- they are better quality and just need to be cleaned.

All good advice above!

Do the valve adjustment before trying to start though.
Look for any wear on cam lobes while there.

Make sure the fuel is hooked into the T and not the vacuum line.
Try Phreds advice to get the carbs to start sucking the fuel.

[Octain]

I had trouble starting my bike after 21 years. It would turn over but not catch. I had installed a new petcock, the carbs were cleaned, electrics were good, so I went over to my neighbours place and got one of his insulin syringes. I filled it with gas and squirted a little bit into the first and fourth cylinder, through the spark plug hole. Just enough to get the plugs to fire and turn over. That did it, and it has been running since then with no problems. It was almost as if there was an air lock in the carbs. that was preventing the gas from flowing or atomizing. I can't explain it other than that, I was a newbie at the time and had spent the previous 2 years rebuilding the bike.

I've done that before as well. A teaspoon or so of fuel in each cylinder got me started a couple of times.
If nothing else, it will at least get it to fire.

[Phred]

I had trouble starting my bike after 21 years. It would turn over but not catch. I had installed a new petcock, the carbs were cleaned, electrics were good, so I went over to my neighbours place and got one of his insulin syringes. I filled it with gas and squirted a little bit into the first and fourth cylinder, through the spark plug hole. Just enough to get the plugs to fire and turn over. That did it, and it has been running since then with no problems. It was almost as if there was an air lock in the carbs. that was preventing the gas from flowing or atomizing. I can't explain it other than that, I was a newbie at the time and had spent the previous 2 years rebuilding the bike.

[Steve]

how do I know what shims to buy? there are so many sizes is it trial and error?

You need to measure your clearance and see what shims you have in there now.

If the clearance is not correct, you make adjustments by changing the shim by the appropriate number of sizes.

For help doing this, consult your service manual. If you don't have one, get one from BassCliff's site.

While you are there, get the tutorial for 8-valve adjustments.

One last tool can be found in my sig.

.

[Rover]

Hello
This fellow has answers

http://members.dslextreme.com/users/bikecliff/