I have a 1991 Phazer that I purchased for my son last winter. It starts good, idles good and accelerates good. The problem is once its warmed up after about 10 to 20 minutes of riding it loose all acceleration. It will still idle perfectly but a little bit of throttle a and it bogs right down. Enough to not even move. If we kill it and start it right back up, it will rev up for a second or two. If we shut it down longer, say long enough to check the plugs, it will have full power again for a minute or so. It did this at the end of last winter and I replaced the coil thinking it was the problem and I ran it a little. I ran fine but I'm assuming I didn't run it long enough as it's doing the same thing again. I've been doing some searching on forums and hear lots mention crank seals. Is this common on these Phazers? Any other ideas?
I'm an automotive tech with limited experience in snowmobiles.
Thanks guys.
I'm an automotive tech with limited experience in snowmobiles.
Thanks guys.
A couple of bucks
VIP Member
The coil is bad. The internal insulation is fine when cold. After it warms up, the comprised insulation opens up and starts to ground out. Buy a BRAND NEW one.
I did buy a brand new one at the end of last season. It was an aftermarket one not a dealer coil. It's doing the exact same thing as it did last year, for this reason I'm thinking it wasn't the coil.
You think I got a bad coil? If so should I get one from the dealer?
You think I got a bad coil? If so should I get one from the dealer?
A couple of bucks
VIP Member
In that case, it is something else electrical w/ compromised insulation.
Plug caps are cheap enough to rule out. Although I doubt it'd be them.
Plug caps are cheap enough to rule out. Although I doubt it'd be them.
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I ordered an original Yamaha coil from the dealer, it comes complete with wires. It should be in mid week, at least I'll be able to eliminate that if it doesn't fix it.
Yamaha Nutz
New member
probally time for crank seals
Got the Yamaha coil today and installed it. My son went for a good 30 minutes ride, so far so good. Plus it's a mild day today so I figure it should of acted up by then.
If I don't post otherwise it's because it's fixed.
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If I don't post otherwise it's because it's fixed.
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Well it looks like the problem is not completely gone. It's acting up again. Slightly different as it doesn't seem to loose all power like before. After riding a while it still gets a major bog. It's not consistent and again it doesn't affect idling. I'm thinking it's something electrical. Would a CDI act up like this or would it either work or quit? Could it be the stator that is week when it's warm?
Anyone know the resistance the stator should be?
Does Yamaha use a safety switch in the throttle? Could it cause this?
Happy New year everyone.
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Anyone know the resistance the stator should be?
Does Yamaha use a safety switch in the throttle? Could it cause this?
Happy New year everyone.
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Throttle Junkie35
New member
You may think Im kidding, but throw a new OEM belt on it and see what happens.
I've done lots of reading on here and I seen a few times mention of adding a ground wire from the chassis to the coil for various reasons. I figured I'd give it a try since I had nothing to loose. My son's been out on a couple rides since and it seems good.
My next step was installing the new belt like Throttle Junkie suggested but I wanted to try just one thing at a time to see what actually fixed it.
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My next step was installing the new belt like Throttle Junkie suggested but I wanted to try just one thing at a time to see what actually fixed it.
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