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cdi tar melted

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Richard

cdi tar melted

for my 1979 cb750k I bought a maintenance free battery off Ebay. It worked good until I went on vacation and while I was gone I hooked up a battery tender. When I came back I tried to start the bike and only the solenoid clicked rapidly. on further inspection I the cdi's had melted the tar. now the battery won't hold a charge. I hooked up a car battery and it started. could the battery tender have caused the problem? How do I check to see if the cdi's are still good?

Richard

Can't wait to get this bike finished so I can start another one Just to drive my wife nuts.

'79 cb750K

shinyribs

Re: cdi tar melted

Administrator

Something definitely got hot. I suppose it's possible the batery tender malfunctioned and over heated things, but with the key off there should not have been voltage going to the spark units at all. Is it possible that the key as left on?

Only way to test will be to crank the bike and check for spark at the plugs.

TOOLS1

Re: cdi tar melted

Administrator

In reply to this post by Richard

The melted CDIs are common, and since the bike started, they must be working, and yes the battery tender most likely overcharged your battery. Also maintenance free AGM battery's should not need a battery tender.
TOOLS

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1976 CB 750-A X 2
1977 CB 750-A X 4
1977 CB 750-K
1976 CB 750 F
1981 CB 750
1966 Kawasaki SG 250
1981 KZ 750 LTD
1973 CB 350
1979 CM 185 Twinstar
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shinyribs

Re: cdi tar melted

Administrator

Maintenance free just means you don't have to add water. They still will lose charge if not ridden regularly.

Richard

Re: cdi tar melted

What can I use to replace the tar?

Richard

Can't wait to get this bike finished so I can start another one Just to drive my wife nuts.

'79 cb750K

shinyribs

Re: cdi tar melted

Administrator

High temp silicone would probably be the easiest. Not even sure it really needs to be hi temp.

TOOLS1

Re: cdi tar melted

Administrator

In reply to this post by shinyribs

shinyribs wrote

Maintenance free just means you don't have to add water. They still will lose charge if not ridden regularly.

I have had them sit for several months, and never had a problem with them.
TOOLS

Richard

Re: cdi tar meltedGot it

Got it running, thanks for all the help.

Richard

Can't wait to get this bike finished so I can start another one Just to drive my wife nuts.

'79 cb750K