Ignition help

[bill61]

Hi, I'm hoping someone out there can help.
I've got a Turismo 125 two-stroke single, c. 1977, registered 1980, with a replacement engine which hasn't run since 1987. It's my first project, with which I'm hoping to teach myself at least some basic mechanics. I've successfully stripped the engine and rebuilt the knackered gearbox, but although I have compression and a spark, I can't start the swearwording thing. I'll keep trying, but long-term, I'd like to replace the points with electronic ignition. Is there anything suitable? Pazon make a universal system, but that involves engineering like making a rotor, way beyond my (very) limited abilities, and getting it done professionally would be prohibitively expensive, and daft on such a low-value bike.
Pazon also offer an Energy Booster Electronic Ignition, in both positive and negative earth versions, to use with a points ignition. I'm thinking this might be a good compromise, but know nothing (not even which version I'd need.)
Does anyone have personal experience of one of these - are they any good, and could a complete beginner fit one?

[R Powell]

Hi Bill,
I have a 1976 Benelli 125 Enduro this has the same engine and electrics as yours. Because your bike does not have a battery you can not use an electronic system . My bike has been blighted with ignition problems since getting it back on the road. Although you have a spark the condenser may be the culprit ?. Try changing it to see of that helps. My bike would not start at first on further investigation i had stripped the woodruff key on the crankshaft putting the timing out. That said i had a 125 Turismo in 1981 and it was very fast,very light and reliable. I think the ignitions are now some 30 years plus old and need some tlc . I have just had the mag coil rewound at west country windings will let you know if that helps!

[bill61]

Thanks for that, mate. I've taken the flywheel off (not easy, as I've got one of those Sealey stirrup-type grips, which worked brilliantly with the engine out, but is seriously difficult to use with the frame in the way) and looking at the woodruff key "longwise", it's pretty much z-shaped, which could be enough to put the timing out. That said, I'm so green I didn't know I couldn't use an electronic ignition without a battery...
Anyway, I'll see if I can replace the key with one that isn't foil-covered plasticine and see how I get on. The coils have been damaged as well, presumably by someone using a two-legged puller or similar to remove the flywheel, but at least it does spark.
Thanks again, and good luck with yours.

[Tornadoboy]

Rotors can also loose their magnetism I don't know if west country can remagnetize them. Failing that there's North Leicester MCs. Morinis and other bikes have magneto powered CDI ignitions is the Pazon one of those. Let us know how you get on so that we can add the info to our lists

Chris

[bill61]

There's no problem with magetism - points gap measuring with the rotor in place is quite a sport... I don't know anything about the Pazon, except that it's claimed to improve the ignition using the original points. I won't be fitting one any time soon, as I'm too ignorant about the whole thing.

[Tornadoboy]

Much of the time fitting an electronic ignition is nice but not strictly necessary. I hated setting points through the holes in the rotors of flywheel magneto setups in my youth. I only drive big bikes these days but I think I missing out on much of the fun especially as my interest in performance dwindles.

You have a spark and have checked the timing which is most likely fixed so I suggest there's nothing wrong with your ignition unless you are using the wrong timing mark. The bike should pop and bang if kicked enough no matter what. Are you sure that you are getting fuel and air to the engine? Is the plug wet after you kick it over? Have you replaced the plug with another. I've had two stroke engines kill a brand new spark plug very quickly even tough it still sparked in the open air. Where are you based? Perhaps someone could come over and take a look for you.

Chris

[bill61]

Hi Chris

Thanks for your interest. It can get very lonely, can failure... I've been through half a dozen plugs. I'll sometimes have some smoke drifting out of the hole when I remove one, and occasionally a wisp from the exhaust - there was one almighty backfire once. Otherwise, not a pop. The plugs come out slightly wet. As for timing, the workshop manual describes one of the mopeds, with the Turismo as an afterthought, and the timing marks are a mystery - at least to me, someone who knows their stuff may well have no problem. Better still, I've put the rotor back on after replacing the woodruff key, and thought I'd best check that I haven't stripped that one as well, as I reckon the timing going out is a major suspect, especially now that I've seen that I did strip the previous woodruff. Now the Sealey tool's refusing to grip hard enough, (I've probably overtightened the nut slightly) so I can't get the rotor off without removing the engine. I can't get a decent grip as whatever angle you come at it something's in the way with the engine mounted - time to look round for something with studs to fit in the holes instead, I can't face taking the engine out AGAIN.
I had one mate who volunteered to help, but he got seriously injured in April, and no-one else will have anything to do with it, usually advising me to find a suitable skip. Can't say I blame them.
If anyone is willing to lend a hand, that would be brilliant, and worth a few beers in anyone's money. I'm in Enfield, on the edge of North London.

[R Powell]

Hi Bill,
A faulty condenser will give a spark but not enough to start the engine. Another thing to check has the stator plate been fitted in the correct position,as you look at it the points should be in the 5,oclock position. might be able to help you in the future i live in Tring[near Aylesbury] in Hertfordshire ,good luck with the Benelli

[bill61]

Thanks.

The stator's fine - I had the rare (for me) nous to take a photo before removing it when I stripped the engine, which according to the seller was running fine when laid up due to no steering head bearings. That was only in 1987... Also, the screws have indented it, which is helpful. I'll leave it alone for a while (domesticity and an even more vindictive MuZ Skorpion in the way...) and then replace the condensor - just ordered one from Burian. He asked for payment upfront! Can't blame him, but I hope it's not because someone took the goods and didn't pay.

[bill61]

Small update. I'm still awaiting the new condensor, but having acquired a decent universal clutch holder I've got the rotor off again. The woodruff key had completely sheared in half. Like all poor workmen, I blamed the tool, and, looking on the net for a better quality alternative, I've learned that they don't stop the rotor from rotating, the taper and a well-torqued nut does... yes, I know you all knew that, but I didn't. Better still, Muggins McMuppet here had greased the crankshaft to make the rotor easier to get off in future. I've also learned that if the rotor does slip woodruff keys are supposed to shear to prevent damage. Small mercies!
They say anyone who represents themselves in court has a fool for a client, this is a self-taught mechanic with a cretin for a teacher. Then again, at least I learned something...