hey have a 87 cbr600 as i was riding the bike starts missing especially when i give it gas it tries to quit entirly, and other times itll run fine, its hit and miss kinda, but always got me home, well today it started doing it again and it would rev up to 4k then the tac would jump up and down sparaticly and the engine would try to die then back to life and so forth, eventually it died and could not get it to start, i pulled one of the plug wires and using a jumper wire tried holding it near ground and see no spark, also this only started happening after i switched to a manual cct, if that might have something to do with it? it hasnt been running as smooth as usual as of late. what should i be checking? spark control unit? how can i test that? any help or suggestions would be much appreciated thanks

 

Look at the r/r, see if it looks all fried. Check the harness connector, as well.

I doubt it's the cct, unless your chain somehow jumped a tooth. (Not likely).

Here's some links to electrical systems and diagnostics...

Charging System Diagnostics - Rectifier/Regulator Upgrade - Triumph Forum: Triumph Rat Motorcycle Forums

https://cbrforum.com/forum/f2-tech-9...-solved-27739/

Technical Resources - Resources for Electrical Systems on Motorcycles and ATVs - ElectroSport

The other possibilitys are either carb issues, or maybe a bad coil.
An ICU failure is pretty rare, not saying it couldn't happen, just that it's way down
on the list of probable causes.

Check your r/r, read over the links I've posted, be sure the charging/electrical system
is in good shape (not a bad thing/waste of time on an older bike, anyway).

Then consider trying some seafoam in a couple of tanks of gas (to clean the carbs).

If none of that works, I would look to pulling and doing a through cleaning on the
carbs next, followed with a sync>idle adjust.

If you pull the coils, your local Honda dealer will probably test them for free,
to verify them. Mine did, anyway.

Al of my suggestions, even if they don't immediately address the issue, will
NOT be wasted time/money on an older bike. They are all things that should be done,
but are often neglected, as routine maintenance. Long term, you'll be happy you did.

Feel free to come back with more questions/comments/etc. These are just the most
likely ways to improve your ride, without wasting your time/cash.

Hope this helps, Ern

 

Great info.. I really don't have anything to add except if you download the service manual from the sticky it has some good troubleshooting info in it for the electrical system also.

 

i have the service manual. thank for all the info, i found out the problem, went back to where i left it last night and first thing i did was pull off the right tail cover to find that 2 wires from the spark control unit were dissconnected
the entire wire harness right there had been cut and put back togather with ****ty electrical tape n the didnt do a very good job, i rewired and wraped it a few time and fired right up without a problem,
there was some great info there though thanks

 

Glad it worked out! I tend to forget about "stupid previous owner tricks", lol

Ern

 

although wanna ask about something else, lately i get alot of chain noise or some kind of engine noise around 7k rpm its loudest, have you heard of this or know what it might be? im gonna try and record a video of it if i can cen a cam that will work wial im moving that fast and still capture sound