Sounds like the starter clutch. The starter sometimes engages then breaks free at the starter clutch. Result is a rather noisy clatter of the chain. You can get replacement starter rollers and springs, but be careful to obtain the right diameter roller. I ordered some apparently for the 305 motor and they are slightly larger in diameter and the starter occasionally slips.
Greg
help with restoration
starterThanks Greg
I have a think and I have come up with a similar answer. I think whats happening is the starter cranks the engine, the engine fires but dosnt start, this rotates the engine faster than the starter so the starter disengages for a fraction of a second and the chain goes slack on the drive side then the starter grabs again and takes up the slack on the chain, big clatter, then the whole process starts again so it sounds like a machine gun. As the chain is not worn and the springs and rollers all look good I think its down to a very slack chain. I am going to shim the chain back and give it a try, the chain is too slack in any case and the time is not lost if it dosnt work. I read a post in the forum with an identical problem but there was no result. Also read posts about how many links should be in the chain some say 60 some say 59. Slack chains seem to be common. I have put a video on youtube showing the first start up for about 40 years. See ca77 first start up. Its bright red. Derek if its not broke don't fix it.
Aermacchi ss350 Gilera 124 James SC1 Scooter Honda CA77
HI Derek
It may be a combination of both. If the engine kicks it removes the tension on the springs and rollers that normally engage. The starter will spin the chain rapidly and it slaps about , particularly if loose. With properly working starter clutch etc it doesnt seem to be an issue if the engine partially fires, at least with two engines I have. The spring tension and roller grab and catch the engine again. The one with the larger rollers seems problematic Hopefully you get to the bottom of it and share the cure. I will probably need to rectify mine at some stage. regards Greg Well panic over.
Counted the links in the chain there are 60, measured the amount of stretch on the chain it was minimal, Placed four m8 x 40 thou thick washers one each behind of the starter mounting bolts and this adjusted the chain it was just right. Tried it again its no different!!! what the ££$$% going on. Its an engine out, cant be. Noticed that it dosnt make the noise when cranking the engine with the ignition is off and I can turn the engine over with a spanner and its free no nasty noises. All together now ITS THE IGNITION TIMEING. How embarrassing is that. What has happened is when I got the bike it was seized so I stripped it down and marked the position of the points back plate so I could put it back in the same place to get it running then I could time it with the strobe later. But as soon as I herd this noise on starting I wouldn't run it for any length of time. It must have been running with the timing WAY to advanced in the past no wonder it seized. Anyway its fine now lesson learned. The starter chain is a lot better now anyway. Another thing if you run the engine with the right hand cover off and the clutch pushrod finds its way out it throws the oil all over the place. if its not broke don't fix it.
Aermacchi ss350 Gilera 124 James SC1 Scooter Honda CA77 adjusting starter chainadjusting starter chain
if its not broke don't fix it.
Aermacchi ss350 Gilera 124 James SC1 Scooter Honda CA77
fitted the starter cover today no problem with the bolts.
I haven't studied the wiring too much yet but it struck me there is no voltage regulator on the bike. Is it like the old british bike wiring were one phase is used to charge the battery without lights and a second phase switched on when the lights are on. Is there any mod to fit a regulator. if its not broke don't fix it.
Aermacchi ss350 Gilera 124 James SC1 Scooter Honda CA77
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