Honda H100SD 1984 Stalls whilst warm

[Accuhaler]

I've got a little Honda H100 that is 30 years old. It's devolved an issues with the cold weather that has come with the winter. The bike starts first time whilst stone cold with the help of the choke. Some times the bike will stall some times it can be left to idle for up to 20 minutes.

But After the riding the bike for some time, and coming to a stop, say at traffic lights, or to turn right the bike will some times stall. And not start up again, for say 5-7 minutes, I know this because after the first 3-5 kicks I'll get off the bike and have a smoke whilst I wait.

After reading the Haynes manual for the bike, I have determined it is not:

Air/fuel mixture, as there is not a lost of power, the spark plug has a brown tan

Compression, as above no loss of power

Ignition sequence, as it doesn't miss fire

Over heating, The bike didn't do this in the summer, and now as it is winter and the temperatures have drop I don't think it is this

Can anyone with a little more experience in these old bikes shed some light on this random behavior of my little H100?

I use a helmet cam, and this recently happened on my commute to work, I'll try and find the footage and upload it.

Thanks in advance

Edit here is the video of the symptoms in action, apoliges for the poor quaily the waterproof case had steamed up and it had been raining

https://www.youtube.com/watch?v=QmmJtnhxRDM

[cb1rocket]

simple case of turning the idle adjustment up? Your trouble shooting is going way past the basics, basics first. How old is the plug? Hard starting indicates a duff plug on the other hand
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[Accuhaler]

Thanks for the reply, I've played around with the idle and have it sitting around 2k now as it's cold. When I first got the bike in the summer the idle was between 1400 and 1700 with out choke.

The plug is only a few months old, and each time I've had it out, last time was only 2 days ago it had a brown tan. Again the haynes manual says this is the correct.

However the bike does smoke alot, a blue colour but you can't smell oil or petrol in it, just your regular 2stoke smell. But it doesn't seem to burn petrol or oil, I can fill the tank 4-5 times before I need to top up the oil.

Whilst on the subject of ignition, I also replace the rectifiers/battery the ignition coil only a few weeks back with parts from Hunts Motorcycle in Manchester I guess I failed to mention that too.

[bypass2]

Try a new plug. What about the choke sticking. what should the tickover be about 1200 revs. what does the manual say the tickover revs should be.

[Accuhaler]

Thanks for your replay. I'll go out tomorrow and pick up a new plug. I really doubt this is the cause tho. As the plug is only a few months out and has a the right colour according to the haynes manual

The Tick over is something I've not been able to find in the haynes manual. Would you be able to suggest some sections to look at?

Choke sticking, I don't think so as I have to manually hold the choke out as it spins back in instantly.

[cb1rocket]

The mixture being correct with a tan colour does not always indicate correct set up. Also revs are far too high, should be sitting at 1300 rpm and the pilot mixture screw 1&1/8 a turn out

When was the air filter last cleaned? Also what's the state of the exhaust baffle?
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[Accuhaler]

Thank you for your reply.

Can you point me in a direction for the pilot mixture? the haynes manual says tan is correct mixture, but I like to think there can always be a incorrect, but correct mixed mixutre (ie the mixture to high, but also correct air/fuel/oli etc etc). As for the rpm how do you know this? I've read the manual but can can't see anything about the rpm at idle.

The baffles, black but no excessive carbon build up. The air filter was cleaned a week or so ago following the instructions in the haynes manua.

[Iain.]

What grade of plug are you running? I had to put a hotter plug in mine over winter or it'd simply foul up and fuck about, refuse to idle...all kinds of nonsense.

Also, next time it does it, open the fuel tank and listen for a whoosh noise. If it does this the tank breather is likely blocked & you're creating a mild vaccum in the tank causing the fuel starvation till the pressure equalises.

[cb1rocket]

I have the offical honda manual for all figures, and pilot mixture screw is the one on the left of this carb side view. Middle is idle adjustment

https://i212.photobucket.com/albums/cc108/CB1Rocket/20131104_204811_zps26e16223.jpg
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[Accuhaler]

Thanks for the replys and all the help you have given me.

It turned out to be a faulty ht lead.

https://i.imgur.com/VxIppnd.jpg

It had happened must have come lose after hitting a pot hole. After that tho it would only idle if I move the lead a certain way. Hunts happily replaced the ignition coil, and I've no issues with the bike over the holiday season.

I however have developed a new issue, a whiny nose that comes from the speed at random speeds. I've lubed up the tacho cables, with some WD fiction spray, and greased up the actual speedo clock with some CV grease, I forget the name of it, 6.99 from Halfords for a big tube.

https://soundcloud.com/xiamen/clocksound

I've uploaded a clip I recorded using my iphone yo can hear it in the link above

Thanks again for all the help so far guys

[cb1rocket]

Clocks are on the way out. Funnily enough these don't seem to last. Cv grease is too thick. You want some 3 in 1 oil on all the clocks and a light dose of engine oil down the cables. Otherwise new cables.

Good news on fixing the idle, you did say it wasn't misfiring though! Next time it does that expect to replace the ignition switch which causes all manner of rough running including not being able to ride it properly
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[Accuhaler]

Thanks for the tips on what lubes to use, I'll oil up the cables over the weekend, just the standard 2stroke oil is okay, or just any kind of motor oil in general?


Now my question about the clocks, is there an upgraded/different one that can be used? As this is the second one I have had in 2 months.

With the HT cable, it was more like a dodge phone changer, ever had on of those phones that had to be in the certain position to charge, same thing here, once I found the position it would idle. I#m guessing the vibrations would move it to make a weak connection at idle, but whilst running the generator made amply enough power to keep the spark sparking?

[cb1rocket]

You can pick up a new coil, HT lead and cap for a tenner on ebay. Very easy to replace that it is not worth the bother replacing one bit at a time

Engine oil is like the car stuff. 10w40 would do, same as your gearbox would use. 2 stroke is too thick and isnt really an oil that lubes stuff other than the engine on a 2 stroke.

No upgrade clocks but some chinky bikes have the same clocks that are a direct fit
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