High end bogging problem.....

[Billy Ricks]

Don't bother with Dynas, check Ebay for some coils of of a GSXR, Bandit, or Katana. From about 2000 on GSXRs got individual coils in each plug cap. You can usually pick them up for about $30 on Ebay. These are a little steep, but if you watch you can get them cheaper. http://cgi.ebay.com/ebaymotors/05-Suzuki-Katana-600-GSX-coils-plugs-0352_W0QQcmdZViewItemQQcategoryZ10066QQitemZ4621745496QQrdZ1QQsspagenameZWDVW

 

[DSchuess]

Another similar problem

Another similar problem

I got my bike (1980 GS550L) last September but didn't start riding it extensively until this spring. When I got it, the plastic connector from the single air cleaner opening to the four carbs was missing. I rode it this way briefly, around the neighberhood less than 3 miles per ride, and it ran fine. I finally installed the part over the winter and it seemed fine at first but on a recent outing with a local bike club (about 45 to 50 riders on 150 mile trip with one Yamaha, one new Suzuki and my 26year old bike being the only 3 non-Harleys, and my bike made it the whole way and was by far the oldest there) I found out that I couldn't go over about 3000 RPM which limited me to about 55-60 MPH. When I first noticed this problem I tried removing the air filter briefly and this did not help. Since then I have completely disassembled and cleaned the carbs and everything seemed to be in order with them, after this I was able to hit about 65 MPH and around 4000 RPM. I checked the manifolds and can find no leaks. I have sync'ed the carbs twice and it doesn't help. Plug 2 is the worst looking of the plugs and #1 isn't much better but #3 and 4 look pretty good generally. From reading previous posts it sounds like one coil controls 1 and 4 and the other is on 2 and 3, if this is correct is it possible that they were attached out of order on my bike? I am going to check the coils in general next but any further advice would be greatly appreciated. Aside from side covers, this bike is bone stock and, as far as I know, was all original when I bought it. Also, it only has 15,000 miles on it but I am not sure how long it sat idle at various points in it's life but I don't think it has been ridden frequently in a long time. Thanks again everyone.

 

[DSchuess]

Follow up on above.

Follow up on above.

Well, after writing that post I went out and checked my coils. I guess I should learn to trust my instincts as sure enough the 1/4 coil is bad. I reads about 4 Ohms and drops about 9 Volts. I first checked spark between each plug wire and noticed that #4 seemed weak, then putting the Fluke meter on the coil confirmed it. Also, my wires are all numbered so as long as they are correct, I answered my own question about the possibility of the boots being switched. Hopefully I am well on my way to getting my bike in proper running condition.