My Gonzo experience.

GLJ

Never go faster than your guardian angle can fly.
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There may be a bad batch of Gonzo boxes on Amazon.
No good dead goes unpunished. A good friend of mine asked me if I would work on a friend of his 83 XS650 Special. Starter problem not engaging. I said ok just needs spring tightened up. When I talked to the guy and agreed to work on it at the end of the conversation he mentioned it had also lost spark. I said no problem if it's the TCI I know of a cheap repair.
Guy dropped the bike off and he was right it would not crank. I was going to order Mikes repair kit but he was out (now they are back in stock). So I dropped the oil and tightened up the spring. Ok can crank the bike now. No spark. Checked for correct voltages and ground at TCI all is good. Coil and pick up Ohm good. Only problem I found was he had resister plugs and plug caps on it. Put in non-resister plugs still no spark. He had just put the plugs in before he brought the bike to me. So I ordered a Gonzo box (GN250) and connectors from Amazon. Parts came in and installed. Had spark great. On the lift engine seemed to stutter between 3 and 4 thousand RPM. I retarded the timing a couple of degrees and went for a ride. Ran great until 3000rpm then ran like shit until 4000, after that ran great to red line. Rechecked everything and rode it again same thing. My timing light showed the same thing between 3-4 grand timing all over the place. Ordered another box. A few days later it came in and was installed It was a bit different 1500 to 2500 ran like shit. Timing light again showed timing going all over the place when it ran bad. Popping and banging. Backfired so bad on the right side one time it busted up the baffles in the exhaust. Had to straighten and weld it back together.
Hmm what's the chances of 2 bad boxes. Next I cleaned the carbs since I know nothing about the bike. Didn't find anything bad in the carbs to account for the bad running. Also did a compression check, 145 on each cylinder. Cam chain and valves ok, 2 valves were .0005 tight. Loosened them a tad. Rode it again same thing ran like shit between 1500 and 2500. Accelerating or deccelling.
I finally came to the conclusion it had to be a Gonzo problem because on deccell the engine was smooth until 2500 then I could feel it jerking and shaking at the same time the back firing would start. Once it went below 1500 everything was fine.I didn't think a carb problem would act like that.
I should mention I changed polarity so many time on the pickup I almost wore out the female end. I was reluctant to believe my timing light as it's a very cheap one.
I fixed it by installing my spare Boyer. Runs great.
The owner was ok with the extra expense of the Boyer. Also very happy with the way the bike ran.
I was hesitant to blame the Gonzo because so many people here have had good luck with them. I should note I bought the 2 boxes from different vendors on Amazon. I think they came from the same factory as the packaging was identical.
 
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Well crap.... there goes the neighborhood.... :doh:
Friggin Chinese bastards and their cheap shit.
 
No I would not give up on the Gonzo. If nothing else it will confirm a bad TCI if your problem is no spark.
A lot of people have had good results with it, just not me. I do seem to have have strange problems from time to time.
I will say Boyer has never let me down. On my next engine I would like to try crank triggered. The French thing looks inviting.
 
My first thought is some kinda interference on the pickup side.
It's possible but I don't have a scope. The wiring to the pickup was perfect, no worn spots.
What's strange is each box had a rpm range when the timing would go crazy and the range was 1000rpm wide. Acceling, decelling, engine load made no difference.
 
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