Hi everyone and thanks in advance for the help. Just purchased this 1986 4x4 fourtrax and it had a bad starter. I put on a new starter and it started right up and ran great. After about 10 min of riding I shut it down and now it will not start. It is getting gas just fine so I pulled the plug to test the spark. Every once I awhile it would act like it wanted to start but wouldn't do anymore than one hit then just keep cranking. When I took the spark plug out is was a bit wet and the spark seems week and very irregular. It might spark 2 or three In a row then nothing for several revolutions. Where should I start. I don't have a manual for this either. Any recommendations on that. Thanks again everyone. Great site and I look forward to learning allot.
Can't start my 86 350 fourtrax
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UPDATE: a little more to go on. After sitting all night outside in30 degree air it fired right up this morning. It ran flawlessly for 8 to 10 min at which time I stopped the machine to see if it would idle ok, it didn't. It idled down what seemed to be normal but just kept dropping rpm and died. Once again it would not restart. Not even try to. Ideas?
Another update: after it cooled off again in the 35degree air this morning it started right up again and ran great until it warmed up in about 10 min. This time I just let it sit and idle most of that time. It was sitting in neutral idling when it sounded like you simply turned the key off. It died perfectly with no hesitation. Again won't restart.
If it were a fuel pump issue it would start with starting fluid or gas in the intake right? No it's defiantly an ignition problem. When it dies I check the spark and it is at best irregular. Sometimes no spark at all. When it cools it starts and runs great for 9 or 10 min. Today I removed the coil and csi and stuck them in the freezer for about 30 min to see if those were the problem. That's not it so now what? Pulse generator? Thanks much for the ideas guys. Everything helps and nice to know about the fuel pump issue too as that may be next.
Ya I'm thinking to check the pulse gen next. As I said after it failed I removed bothe the coil and cdi and put them in the freezer to cool them but still nothing. Doesn't the pulse gen sit in oil which would make it cool much slower? What does a pulse generator even do? I read somewhere that someone said the oil temp sensor has the authority to kill the engine. Is that true? If so it could be that to I guess. Thanks again for letting me bounce ideas. Everything helps.
UPDATE: Ok I did the ohm check on the pulse gen and it was getting NO continuity. So, I went ahead and took it out, not real fun. I put it in the freezer for about 10 min and what do you know, 260ohms which is still not in spec but does suggest a failure due to rise in temp. I have ordered one locally and will be putting it in next week sometime when it comes in so stay tuned for more developments. Thanks again everyone.
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Yeah, the pulse generator is in oil. The pulse generator triggers the CDI to "fire" at the correct time in relation to the position of the crankshaft/piston.
No, it will just cut power to the fan motor if the fan motor gets stopped for some reason, so it doesn't burn up the fan motor.
Yeah, I would say you've found the problem. Great!!
FIXED!!!!! It was the pulse generator. After removing it I put it in the freezer and it would ohm out at 260, normal is 300-350 but at room temp it was a completely open circuit. Replaced it and it starts and runs perfectly. Thanks again everyone for the insight and help.
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That's great, glad you got it fixed!!
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