Dead again

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Debby,

Condensers are cheap!

Faulty condensers will cause the engine to run erratic with symptoms of a carburetor being out of adjustment. I think I remember asking if you had changed them?

As norbsa pointed out, faulty condensers will cause excessive spark at the points. This is easy to check: with the ignition on, flick the points open and closed by hand and if you see a big-fat-spark at the points, you have a bad condenser. Moreover, you will see stalagmites/stalagtites on the faces of the points if your condensers are shot.

Check it out and let us know what you find.

Regards,

Jason
 
Condensers

Recently I was working on a Yamaha 650 that had been sitting several years. It wouldn't really run at all and the spark didn't look too good. I replaced the condensers and voila! it ran. Otherwise I just cleaned the carbs and adjusted the timing chain and points and it runs quite well. Like somebody else said, condensers are cheap.
 
I spent a few hours working on it last night and found the problem! It turned out it was only running on the left cylinder. The right side wasn't even firing. The points were dirty and corroded and a little work with the volt meter showed the ones for the right cylinder were so bad they weren't conducting at all. The voltage drop across the points was exactly the same regardless of whether they were open or closed! So it was like the points were open all the time. I was able to clean them up a bit and get the bike to run on both cylinders but today I went down to Denver and bought new points and condensers. Also one of the wires had broken and was soldered back on in a very non-workmanlike manner. It was still working but its failure was just a matter of time. So I bought new points leads also.

Now I just have to put the new parts in and retime the engine. I feel confident in predicting it will run much better!

I know, I should have checked the points more carefully a long time ago. I feel a little embarassed about that actually. But with all the carb problems I've had I thought it was The Curse of the Amals again. This bike has just had a lot of little mechanical issues that all have to be sorted out and made right. Hopefully I'm getting closer now...

Debby
 
Debby, Not being able to find real Lucas points is the problem that has sent many to hook up Boyers. The copies can require many re-gaps before holding still. The plastic wear shoes don't seem to last as long as the lucas brand. I have a man here in Michigan with an old stock Lucus but the last time we talked he needed 30.00 per set now you see why a Boyer and 110.00 gets to sounding better. norbsa
 
uh oh. well, we'll see how it goes. I purchased genuine Lucas condensers (all he had) but jap points (also all he had). I'm a bit reluctant to go with a Boyer due to all the problems I hear about - breaking wires, black boxes that go out, and sometimes they seem to have a vicious kickback. One guy on INOA recently got his ankle broken from his Boyer-equipped bike kicking back! I need my ankles for other things so I'd really prefer to stick with the points unless they prove to be *really* troublesome.

Debby
 
Hi Debbie,

It sounds like your making progress!

I think someone once said that 90% of all carburetor problems are electrical!

What is HTH?

Jason
 
Interesting quote. I definitely fixed some real carb problems but this latest one did indeed turn out to be electrical. The more I learn the more I realize I don't know!

Jason, HTH is geek speak for Hope That Helps

Debby
geekette
 
Debbie,

Thanks for the translation on HTH. Perhaps posting a list of these abreviations would be helpful?

Interestingly, the 90% rule sometimes works the other way around. For example: "...90% of all electrical problems can be traced to faulty carburetion."

Jason
 
Well done Debby !!

You had to win in the end.

Remember, Compression, Spark(at the right time), Fuel & it should run.

I bet you are kicking yourself for not making sure the points were right when you first brought the bike. You should have replaced/checked them on the first days maintenance when you cleaned your carbys etc.

Boyer ignition is bad you say ?????????????????????

mmmmph, set it & forget it.

Well alls well that ends well they say. Congratulations once more.
 
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