Rebuilt Honda 125M not starting

[vonflak]

Had to rebuild the 125M on my 84 Honda ATC. Now that it's on the bike it won't start. I'm getting spark but the plug is not very wet. I made all new gaskets except for the head gasket which was in good condition. I hav'nt touched the carb and it only sat about a month. plus it does nothing with starter fluid squirted directly into the spark plug hole. I've adjusted the valves to .005 per the clymer.

While pull starting sometimes i will get a promising flutter but nothing on electric start.

I fear i may have the timing off. the book says to put the "o" on the cam sproket straight up but it also says to put it on the notch which is at the 9 0'clock position. I put the "o" on the notch. If the timming is bad would
nt it back fire or carry on some? i'm getting nothing. which way is correct?

what else should I try?

[mrcribbs]

Pretty sure the valves should be .003 but that shouldn't be your problem. I'm guessing timing... I don't remember an "o" but the manual says "put the "o" at the top of the head"

[vonflak]

i just re-read it, the top of the head would be where the notch is and where i aligned the "o"

[EarlyBronocGuy]

Did you pull the ignition rotor apart from the shaft the centrifugal weights are on? It'll go back together either way - the correct way, or 180 degrees off. Remove the timing cover and use a flashlight to see the "T" mark on the flywheel, and line it up with the notch on the case. Check the ignition rotor, it should be pointing directly at the hall effect magnet - it it's not, your spark will not occur at TDC.

If it's off 180, pull the ignition rotor off the end of the camshaft and reassemble it the right way. If it's off only a little, you're off a tooth or two on the timing chain.

[vonflak]

Thanks EBG, that worked, it was off 180 deg. The book said TDC but did'nt mention it should be on the compression stroke. It fired up after that and I let it run a few minutes.

I shut it off and got things cleaned up around it to take it for a ride. I had to rebuild it because the arm that stops the shift drum broke off at the boss. When I got it back together i tried running it though the gears by hand and it hung up on first. It will only shift from first to second and back. I'm hoping with the engine running and the gears moving this will correct itself.

Anyhow, I wanted to ride it and address that problem next. I started it again and moved it about 20 feet and tried to shift it, I was to slow about it though i think and it stalled, now it won't start again. Checked it for fuel and spark again today, seems ok but still wo'nt start, any ideas on that?

[EarlyBronocGuy]

Thanks EBG, that worked, it was off 180 deg. The book said TDC but did'nt mention it should be on the compression stroke. It fired up after that and I let it run a few minutes.

I shut it off and got things cleaned up around it to take it for a ride. I had to rebuild it because the arm that stops the shift drum broke off at the boss. When I got it back together i tried running it though the gears by hand and it hung up on first. It will only shift from first to second and back. I'm hoping with the engine running and the gears moving this will correct itself.

Anyhow, I wanted to ride it and address that problem next. I started it again and moved it about 20 feet and tried to shift it, I was to slow about it though i think and it stalled, now it won't start again. Checked it for fuel and spark again today, seems ok but still wo'nt start, any ideas on that?

Make sure it's in neutral, make sure the kill switch is in run, make sure the petcock under the tank is either "on" or "reserve", make sure there's gas in the carb. If it's cold, pull the choke out and apply about 1/4 - 1/2 throttle and crank it for a while. If it cranks for more than 30 seconds without starting, it's not going to start until whatever's wrong gets fixed.

Pull the plug, clean it, gap it, and hook it back up to the coil wire, but don't screw it into the head - ground the base of the plug to the engine and crank it over a few times, watch the plug gap closely for a spark. No spark at all, it's either not in neutral, the neutral switch is bad, the kill switch is grounded, bad coil, bad CDI - lots of reasons. Check the easy, cheap ones first.

Weak spark, could be the battery needs a good charge - cranking the engine over with the starter uses a lot of juice, there may not be enough left over for a strong enough spark. Try spinning the engine over with the pull starter and see if it makes a difference in the strength of the spark. Ideally, you want a bright blue spark, but even a yellow spark will get it started. Jump start it off a car, see if it cranks over a lot faster.

Good spark (at the right time, TDC), but no start - either no compression or no fuel/too much fuel.

If you've checked everything and still can't find a reason for it not starting, or it'll start, run for a few seconds, die, then not start until you've cleaned the plug again, it's either REALLY rich (dripping wet plug), or possibly just a bad plug. Put a new, gapped plug in there before you tear into the carb it the old plug isin't dripping wet every time you pull it out.