Won't Start

Hey Guys I need some help, I'm having trouble starting my sled. The problem has just started 4 days ago, after I was out riding in alot of fresh powdersnow. The problem is that, when I've been riding for an hour or so and stop the engine and go to start the engine after a break of 15-20 min, it takes 20 to 30 pulls before the engine fires up. I'm very confused about what the problem might be, because when the sled actually starts again, it fires up normal, like it's roaring "Yeah, let's tear that mountain up". I'm thinking it's an electrical problem, but I'm not sure. Has anyone had this problem before?

Sounds like the stator is starting to weaken. Happened to mine this year...same symptoms.

Yeap, Sounds like a Yamaha Stator...I've been through a couple of them.

Alright, thanks for the help, much appreciated! So, how can I make sure that's it's the stator that's calling it a day? If it is the stator, I see it as a lose/win situation. By that I mean that I've been wanting to upgrade the stator, so I could replace the old headlight with a dual bulb version. How long do you think I have before the stator totally quits?

I'd fix it before riding it anymore. Usually when they quit your on the end of a rope being towed by a Polaris.....

The stator has 2 curcuits. One set of coils (not the ignition coils) is for the charge/lighting system. The other set of coils is for the ignition. It's possible for "one half" to bad, ie no spark but has voltage to the light's when you pull it over. You can test them with an ohmn meter, but if your's only act's up when hot. You need the warm the motor up to reproduce the failure, to actually get a bad reading on the ohmn meter.

Buddy had one go out on a mountain ride, no warning just shut it off and wouldn't restart. Since it was a warm spring day, we were running without hoods. We went to tow him out, and the engine bay would fill up solid with about a 100 punds of wet heavy spring snow! What a pain in the arse, we ended up pushing him over the edge of a drop off, because we couldn't drag the thing up some big hills to go out the normal way! He rode it out and we went around and caught up to him to drag him out the rest of the way. Took about a week for a that snow to melt around the motor.

Anyway sounds like your's is giving you some warning. I'd replace that sucker, before it leave's you stranded somewhere.

Thanks for the quick responses guys, i'll order a new stator before going out again. I actually now recall that I have been pushing my luck with the sled, because twice the sled wouldn't start yesterday in the backcountry, and we we're like some 40 clicks out in the mountains, like it was really bad, had to get help from a buddy to help pull and start it up. Now just a quick question here at the finishline, do I need to change anything else besides the stator to fix the problem? 'Cause I don't have the servicemanual for the sled and it would save some time, to know what to order before taking the engine apart. Thanks again.

Also check your spark plug caps. They should ohm out at 5000 ohms, mine were in the Meg range when I was having my hard starting issue. I replaced the caps and my stator at the same time.

You should be abel to take ohm readings from your stator also, that is how I trouble shot mine. I dont remember the readings though.

Tod

Bad sparkplug caps can actually go hand in hand with a bad stator because the increased resistance in the caps puts extra load on the stator

In the March 2005 issue of snowtech there's a tech tip for yamaha triples. Same symptom and they recommend to start with the plug caps.

I would change the plugs caps first and try that before I went and changed the stator. A stator should be lasting awhile.

Now I get a little mixed recommendations, I can add to the symptons that when the engine ran, I could take the caps off each spark plug and hear the engine go down in rpm. Wouldn't that eliminate the cap problem?

Here's what I would do, unscrew the caps off the wire's. Check the cap resistance between the contact for the plug and the stud that screw's into the wire. Spec is 5000 ohmn's (5K ohmn's) at 20*C (68*F). If it's higher then 5000 ohmn's, replace it. If it's lower then 5000 ohmn's (unlikely) it may cause some RF noise for radio's and other electronic componet's, but probably not the starting problems you have.
The purpose of the resistor cap, is to reduce RF radio noise. Serve's the same function as resistor spark plug wire's in your car.
When the resistance is high in the cap, it requires more voltage from the ignition coil to fire the spark plug. This higher required voltage from the secondary side (plug wire) of ignition coil, in turn requires more amperage from the primary side (the small leads into the ignition coil). The ignition coil get's it volt's/amp's right from the stator. It's the higher amperage requirement from the stator that stress'es it.
So you can see how bad plug wire's/caps could cause a stator to go out.
Check your caps, if their bad replace them. However I would recommend you replace the stator also, because it could go out at anytime, anywhere.

Changing a stator is not to bad a job to do. reqiure's pulling the recoil and flywheel. So you will need a steering wheel/flywheel puller. HTH