Hey all,
I'm running into frustrations trying to get my '64 CB72 ready for the fall Motogiro here is New England. I had it running pretty good but discovered that the rectifier was shorted, sending up to 40 volts to the battery. I've corrected that by replacing the rectifier with a Tympanium I had lying around. I have a good 12-13 volts going to the battery but it will only take 7-8 volts so I assume it's toast.
But I can't seem to get the bike to run reliably on both cylinders. Either one side or the other cuts out under load. I've tried swapping plugs and replacing them (they're new), I've replaced the points with (very expensive) genuine Honda parts, I've tried running the bike with a battery charger attached to see if maybe a steady 12 volt power source would help. Nothing changes the point at which one cylinder starts cutting out. I put my timing light on it and I can see when the spark goes away, so I'm 99% certain it's not fuel-related. At times it would appear that the spark shows up on or near the opposite-side timing mark (!?).
A new battery and condensor is on the way. If anyone has a more definitive answer than my trial and error method I'd appreciate advice. Or if you'd like to show up at my garage in southeastern MA and I'll provide the beer!
Thanx,
Neil
Intermittent spark
Intermittent spark
Re: Intermittent sparkUntil ya get a good 12 VOLT source that engine won't ever tune in and run well.
You have had the best there is as far as knowledge and support with your problem. Now get that battery and SLOW CHARGE it over night (1, 2 AMPS at most) (10 AMPS will kill it) and go from there. ...............LM
Thanx, but I just don't understand why the bike won't run using the battery charger as a 12 volt source?
I'm definitely getting the new battery, but if I recall, my little CD175 would run just fine on a near-dead (6 volt) battery. Being another Honda product of the same era ('68) wouldn't it behave the same? I guess it has to make sense to me in my limited understanding before I can rest in it. Bikes:
'79 BMW R100RS '03 HD Sportster 883R '66 Benelli Sprite '64 Honda CL72/CL77 motor
Ok, so I got the new condensor, and the new battery. Thinking for sure that 40 volts from a shorted rectifier could've wrecked the condensor, I put that in first. Still popping and missing at revs. Drop the new battery in and bingo! The motor revs like a champ, proving all the best advice I had received both here and on the Yahoo Group, that a 305 won't run right with a bad battery.
So I'm going to go crawl into a hole somewhere along with my backwards rotating 160 theories. Maybe I'll try my hand at relacing a wheel. That should keep me busy for awhile! :) Bikes:
'79 BMW R100RS '03 HD Sportster 883R '66 Benelli Sprite '64 Honda CL72/CL77 motor
Some things and some folks take a while to get it in their head that things/machines work in ways that they don't and may never understand. Now ya need to get your hands on all the data that is for your bike that is offered on eBay and read and read and learn as most of us have. ..............lm
Ya need to get any parts book and a CLYMER M331 manual that are on eBay often then ya should read and read and look at the pics and get a really good idea of the actual makeup of your bike.
Even today I find/see things that I hadn't before. ................lm
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