Ariel Arrow starting

[TonyBaxter]

Not sure what you mean by the points being old affecting timing. If you cleaned the faces to avoid arcing, checked gap, and lastly the actual timing they should work pretty well. Is it actually back firing or spitting back ? If it's spitting back, may be air leak in inlet or wrong mixture.

[White.John.A]

Hi Tony, It is back firing very loudly in the exhaust pipes. It sounds as if the engine is going to explode. The points are old. I have not tried to clean them yet as I have been trying to get the electronic ignition to work. I agree that I would not expect them to cause this problem. I am not sure what the problem could be. I assumed it was bad timing and spent the rest of the afternoon making adjustments. But I didn’t, manage to improve the situation.

[grahamhibbs]

Well I hate to be the bearer of doom but I had the very same problem and it was down to the crankshaft seals being completely worn out.
Changed for Niton seals....... cured.

[White.John.A]

Hi Graham, that would be bad news. I have just replaced the seals, brgs etc and had it rebored. For such a simple engine it sure is giving me something to think about. Experience is what I’m getting. I’m on a steep learning curve.
JOHN

[TonyBaxter]

Hi Graham, that would be bad news. I have just replaced the seals, brgs etc and had it rebored. For such a simple engine it sure is giving me something to think about. Experience is what I’m getting. I’m on a steep learning curve.
JOHN

John, that's what makes these old bikes such, er, fun ............
I've just put an MZ engine back together for the second time, fixed an issue that stopped it shifting into first gear. Bolted cases back together, put the engine in the frame, tried the gear shift again, and......it doesn't go into first - Aaaaagghhh !!

[grahamhibbs]

John. you may have seen it but someone on the forum was working on a way to measure the pressure in each side of the crank case, that would be the only way to tell without dismantling the engine again.
question is were the seals damaged Reassembling the engine.
Regards
Graham

[White.John.A]

Yes Graham I have read the ideas on the forum. I may well try some of them to see if I can check the seals as it is possible to have damaged them when I assembled them. As the engine is now running I will look for other problems before I consider another strip down. As members have said, the points could be cleaned and new condensers fitted. With an old bike I am finding everything becomes suspect.
John

[iansoady]

Too true......

And worse still, many of the "new" parts turn out to be worse than the old ones you replaced them with.

[dave.owen]

I've been told by a local bearing supplier that seals have a limited life in storage. They replace stock after a relatively short period of time, so using nos seals isn't a good idea. Best to use newly made seals.
Dave

[ken-drink]

well i tried to fit my kit from draganfly over the weekend, total failure not even a spark, followed instructions very carefully and did it by the book, not a spark, took the kit off and tested the unit that replaces the points, does not work so got to ring draganfly and see if i can get a replacement.

Ken