Johnny

Good luck with the rebuild. I'm rebuilding an M80 and I've had a lot of excellent advice from the guys that know a lot more about Bultos than I do. Best advice I can give is don't be afraid to ask.

Been in the garage too long looking at that dial gauge! Cheers

Yep, you're right. Disconnect the green wire and it works. No idea why though. Cheers.

I use Shell V Power in my twinshock race bikes because its 99-100 octane, but they have alloy tanks. I knew that Tesco high octane was also about the same octane rating but I didn't know that it was ethanol free. Interesting- I might give it a go. On a slightly different note what 2 stroke oil do people use and in what ratio?

Points and condensor are both new and points are gapped correctly. I agree, the fag paper method is easier but I had the bits in the garage to make the light and buzzer set up so I thought I'd use that method. Just need to use it properly! I will try disconnecting the green earth wire when I get time later. Thanks for the suggestions.

Ok, what am I doing wrong? I think I've been away too long from Bultos racing 4 strokes with electronic ignition. I've rigged up a lamp and buzzer to test the ignition timing on the M80 I am rebuilding. There are 3 wires from the magneto. Black, green and yellow. I assume yellow is from the lighting coil and so I've blanked it off. I've connected black to the coil and green to a good earth. To test the timing I've attached one lead from the tester to the black wire which I've disonnected from the coil, and the other lead to earth. I've set the piston at TDC and rotated backwards towards 2.9mm BTDC. Problem is the light doesn't go out when the points open, which I thought it should. Have I got it wrong?

Apologies if this has been raised before, but what's the best thing to do with an old glassfibre petrol tank that has not been used for many years? I've swilled the tank out with petrol to get rid of any loose debris on the M80 I am rebuilding and removed the tap ready for a new one. But the inside of the tank is very sticky with a yellowy brown film that sticks to your finger when you wipe inside the tank. Is this likey to be old 2 stroke oil or something worse like the effect of ethanol? I don't know how long ethanol has been added to petrol and I don't know how long the bike has been stood. Should I fit a new tap and fill it up and hope for the best or is there something you can use to seal glassfibre tanks?

Thanks for that Woody. I didn't buy the tensioner, it came in the box of bits with the bike. After looking at the picture I've fitted the pad on the other side of the arm and bent the spring the other way to locate on the swingingarm and it works a treat. Cheers

A different spring arrangement would make sense. Just got to find one now....

I'm having problems fitting a chain tensioner to my M80 that I am rebuilding. Its one of Bultaco UK's. It appears that the only way to fit one on an M80 is to the rear brake torque arm bracket on the swinging arm, and the tensioner has to face forwards. I've never had a bike with this arrangement before. All the bikes I've had have had the tensioner 'trailing'. This might not be a problem, but the chain is rubbing on the tensioner spring, despite bending it as far as I can into the tensioner. Has anyboby else had this problem or can suggest any solutions? Cheers

I look forward to trying one of your trials on my 1971 Bulto.

Cheers. Just ordered a pair.

Just been in touch with Pyramid Parts for new steering head bearings and all they have listed is Bultaco Classic mx bearings. Bearing size is 25mm x 45mm x 12mm. Are these the ones?

Cheers guys. Combination of angle grinder and chisel worked a treat. Will contact Pyramid Parts for new bearings tomorrow.

Hello everyone. I've just bought myself an M80 which I am hoping to get sorted so that I can do a few trials this winter. I had a couple of Bultos when I was a keen young lad in the seventies, and have a soft spot for them! I have been looking at some of the posts to get advice on what to look for and how to sort things. Its been really useful. Clearly some of you guys know your Bultos. One thing I have not been able to find is how to remove the lower steering head bearing cup. I've tried heating it up and tapping it up the stem but the dust cover is starting to distort and there's no sign of it moving. Any advice? Also any other advice specific to rebuilding this model would be great. Cheers