Suzuki 2 Strokes

Seeking other perspective as I've had trouble diagnosing this on my own.

Bike can run fine for up to 1000 miles then the right cylinder will get intermittent combustion that can last anywhere from 50 miles to just a second or so. Right cylinder combustion can be something like: 5 seconds off, 1 second on, 10 seconds off, and so on, often followed by a pop from the right exhaust pipe and then back to normal.

It seems random in that it can happen at any rpm, throttle opening, speed, petcock position; and I haven't been able to do anything to cause the problem to show up or go away.

After this problem first came about during last year's trip I installed an electronic ignition and thoroughly cleaned the carbs/petcock. The bike has since run fine in all my local riding but then during this year's trip the problem occurred several times again. With its limited occurrence, usually while far from home, troubleshooting has been difficult.

It sounds rather like a coil breaking down when it gets hot on a long run.

It could also be some sort of fuel issue, but i'd fit new coils and see if that fixes it. They are cheap enough. And fit new plug caps at the same time.

Thanks Richard, Coils have been on my mind too. Where do you purchase yours?

I got mine from Ignitech in Europe. I was going to get a set from Rex's speed shop http://www.rexs-speedshop.com/epages/es ... ucts/HTC32" onclick="window.open(this.href);return false;

I do like this set, but you could do them cheaper yourself
https://www.ebay.com/itm/Suzuki-GT-750- ... 9J&vxp=mtr" onclick="window.open(this.href);return false;

https://www.ebay.com/itm/SUZUKI-IGNITIO ... RD&vxp=mtr" onclick="window.open(this.href);return false;

These might work
https://www.ebay.com/itm/2-IGNITION-COI ... 0005.m1851" onclick="window.open(this.href);return false;

Contact the vendor and ask them for primary and secondary resistances and if the primary is 4 ohm +/-1 they should work. They look just like the coils i used which I never bothered to check resistance of..

Thanks again for your help. These are the coils I ended up purchasing. In addition to being listed as for the GT750 they have the correct 80mm mounting length and plug caps are included: https://www.ebay.com/itm/Ignition-Coil- ... %7Ciid%3A1" onclick="window.open(this.href);return false;

I haven't needed to crimp pin connectors yet so am looking forward to learning the technique.

Josh

I had hoped to post sooner but it took some time for the parts and crimping tool to trickle in through the mail. Credit to Vintage Connections for having the reproduction bits available.

My 7 year old wanted to help and ended up crimping most of the terminals himself! We had a great time working together in the garage. I think he knew there'd be a test ride involved if we got everything back together. We did, and the bike seems unusually smooth now, which leads me to believe that right coil may have been weak for some time. I won't know for sure if the intermittent issue is solved until the next trip but am hopeful this cured it.

I should mention for anyone considering the replacement coils I linked to above, they are a little longer where the coil wire comes out so I had to drill new mounting holes in the frame about 1/2" left of the originals to allow the center coil to miss the frame.