jim9755 Posted February 4, 2009 Author Report Share Posted February 4, 2009 just been out with the bike, cleaned the breather out but it made no difference the bike still dies after a while but was worth a try any way. the bike is cleaned up and put away now for the next couple of months but in the mean time if any one has any other ideas then let me know, hopefully the ht coil and some other bits should come whilst im at work so can hit the ground running in april and get it sorted. at the moment im thinking of a complete rebuild new bearings/seals/gaskets rings the lot when i get home, hopefully throwing a bit of cash and time and effort at it might pay off. in the mean time thanks for all the help and keep posting the ideas and will let you know how i get on cheers guys Quote Link to comment Share on other sites More sharing options...
classicglory Posted March 30, 2009 Report Share Posted March 30, 2009 www.roosterignitions.com do an electronic ignition module for D1-D7 for Quote Link to comment Share on other sites More sharing options...
jim9755 Posted April 1, 2009 Author Report Share Posted April 1, 2009 finished work for a few months now and back in the country. I have a rooster ignitions bantam booster kit for the bike, tried fitting it yesterday and the bike wouldn't start at all with it fitted, the spark looked weaker than when i was running it with the points so tomorow will fit the new ht coil then fit the rooster booster kit, hopefully with a new ht coil the ignition kit will be able to work properly. cheers for the help Quote Link to comment Share on other sites More sharing options...
ciderheadz1 Posted June 14, 2009 Report Share Posted June 14, 2009 I have a D7 that was showing exactly the same symptoms you describe and I went the same way you did changing all the electrical components to no avail.Mine too was freshly ringed but mine was rebored with new piston also and like yours would start straight away and run nice for half an hour then stop and not start for many hours untill cooled right down.Bad news is that mine seized and the non starting after 30 mins was the bike partially seizing.I pulled the barrel off to find all the rings mashed up in the piston and the bore badly scored.It was odd at the time as it was sparking well and felt like it had good compression but this was down to it starting to pick up in the bore and making it feel like it had good compression.I had mine rebored again with a new piston and all is well again and have just returned from a 60 mile ride.I believe pistons and rings aint what they used to be and was told by the chap who supplied the piston to give it a 3 thou clearance in the bore or you will get grief which was born out by the old guy who machined the barrel and said I done it to 2 thou as it should be and it didn't feel right so he took it to 3 and was then happy with it.I know you have only done rings and apart from the obvious like making sure they are between the pegs in the piston be aware that not all rings/pistons or machining can be relied on.My bet is rings are your problem.Good luck. Quote Link to comment Share on other sites More sharing options...
trials339 Posted July 22, 2009 Report Share Posted July 22, 2009 hi, new to this site. hello to all.the magnets in the flywheel lose magnetism when hot.try a new one. Quote Link to comment Share on other sites More sharing options...
cvgmmartin Posted July 23, 2009 Report Share Posted July 23, 2009 I had a similar syptoms on my Bultaco, in my case the cure was replacing the crankshaft seal. Are you using a plain plug cap? Quote Link to comment Share on other sites More sharing options...
alan_nc Posted August 1, 2009 Report Share Posted August 1, 2009 I ride a '59 D7 in Trials. Had very similar problems. 1st I put a spacer between the carb and the cylinder. A Norton 650 carb mounting flange is perfect (about 1 and 1/2" long). Use gaskets on both ends to avoid leaks. 2nd Condenser: A condenser is a condenser. You don't want the standard BSA unit. Check the mf (micro farad range), of the unit. I found that old Chrysler units had a much higher rating (check hot rod web sites for ratings). Couple of things to check: When it doesn't start can you drain petrol from the crankcase? What color is the spark plug?, Probably need to go to a hotter (deeper tipped) plug. What kind of petrol are you using? They were designed to run on leaded gas (which runs cooler). I am able to buy leaded gas at a specialty store, most Air Ports have it. What oil/petrol mix are you using? I use a good synthetic oil and mix at 20/1. It is possible that the seals begin to leak after 1/2 hour of riding or the piston expands enough to stop the motor. Try this: After about 20 minutes of riding get into an open area, put the bike in third gear and ride at about 20 mph for 5 minutes. If you can then ride for another 20 minutes you definitely have a heating problem. They sure do seem to run hot - so do whatever you can to keep it cool. Alan - good luck, they sure are a fun Trials bike. Quote Link to comment Share on other sites More sharing options...
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