MXZ 600 Help

[Kerick]

Ok the other day I went out on the trails with two of my buddies. I pulled the sled out let it warm up some then went riding felt good sounded good. Then we get maybe a mile from my house and it just dies out. So I go to pull it over and its stuck. Wait a minute and try again and it fires up. So I drive it another mile or so and does the same thing. We take the belt off and tow it to my buddies house which was nearby. Noticed the oil premix was low so we added some ( My light was never on). So we try to get it back to my house thinking that was the problem and again dies out. Tow it back to his house and wait for his dad to get there and he looked it over coolant was flowing had good comp plugs looked great airbox was clean. So we ride it around and its fine then we ended up even going on a trail ride with it. Soo strange at first I thought I seized it then the other theorie his dad thought of was a wire was shorting out preventing spark and gas was still being poured into the cylinder causing vapor-lock. PS: Sorry for the long story but I hate when people post "my sled died what's wrong" lol. Thanks in advance guys!

[Maico]

Even with a dead cylinder...it will still push the unburned fuel out the pipe. Check the carb(s) and make sure there's no water or crud in the bowls and that the mains are clean and clear.

[MTS]

So I go to pull it over and its stuck.

Care to explain that a bit more?? This a fresh motor?...Miles up ect...?
I'm not Familiar with the MXZ but my 01 Summit is Close I'm sure. Yours have a DPM set up...? What did the plugs look like...??...Could be a few things...

[NINJA]

Sounds like you may have a crank bearing crapping out on you. I don't think it's a seize because you said plugs looked good. If you had even a temporary seize, you'd see a silver coating on the groundstrap of your plug, that's transferred aluminum.

[Kerick]

Care to explain that a bit more?? This a fresh motor?...Miles up ect...?
I'm not Familiar with the MXZ but my 01 Summit is Close I'm sure. Yours have a DPM set up...? What did the plugs look like...??...Could be a few things...

Yes it was stuck. Then itd get looser and looser. Almost 7,000 mi on her. Plugs looked good no shiny metal on them.

Sounds like you may have a crank bearing crapping out on you. I don't think it's a seize because you said plugs looked good. If you had even a temporary seize, you'd see a silver coating on the groundstrap of your plug, that's transferred aluminum.

Would I be able to hear the bearing knocking around? What do you mean by "groundstrap"?

[RIDE-RED 250r]

Any time an engine shuts down and gets "stuck" something is wrong. If the topend seems good, my guess would also be a crank bearing going south. The ground strap of the sparkplug is the little strap that is attached to the outer plug body and extends up and over the center electrode. These engines have O-ringed heads and its quite easy to pull the head and have a good look at the tops of the pistons and the cylinder walls. Just drain the coolant first. Can you get the engine to stick by turning it over by hand?

Another possible cause is a sticking primary clutch. This could be caused by the clutch being very dirty inside, a broken primary clutch spring or a combination of the 2. The next time it quits on you, dont immediately try to re-fire it. Lift the hood, open the clutch guard and see if the primary clutch is stuck closed on the belt. If not, remove the belt and turn the engine by hand and see if it the problem feels like it coincides with piston stroke or random.....That will get you pointed in the right direction..

[Kerick]

Any time an engine shuts down and gets "stuck" something is wrong. If the topend seems good, my guess would also be a crank bearing going south. The ground strap of the sparkplug is the little strap that is attached to the outer plug body and extends up and over the center electrode. These engines have O-ringed heads and its quite easy to pull the head and have a good look at the tops of the pistons and the cylinder walls. Just drain the coolant first. Can you get the engine to stick by turning it over by hand?

Another possible cause is a sticking primary clutch. This could be caused by the clutch being very dirty inside, a broken primary clutch spring or a combination of the 2. The next time it quits on you, dont immediately try to re-fire it. Lift the hood, open the clutch guard and see if the primary clutch is stuck closed on the belt. If not, remove the belt and turn the engine by hand and see if it the problem feels like it coincides with piston stroke or random.....That will get you pointed in the right direction..

No it'll only stick when I ride it. And the primary clutch actually does seem like it might be what it is. I mean it was running fine for the full trail ride after that. Seems like if it was engine related it'd shut off. Ill have to take a look at the clutch.

[RIDE-RED 250r]

OK, when it sticks, does it have tight spots at certain points of the crankshaft revolution? Or does it feel equally sticky or tight all the way through a complete engine revolution? If its the latter, its probably time to get that primary clutch cleaned and serviced!

PS: dont try to dissasemble the clutch unless you have the proper puller to remove it from the crankshaft, and the proper tools needed to disassemble it once its off the engine....parts will go flying across the shop if you doo!

[RIDE-RED 250r]

Oh, and if you need tools, i know of a sponser on Dootalk.com that makes an outstanding tool kit that has every tool you need to remove and completely disassmble both of your clutches. He also provides a free instructional DVD opon request when placing an order if you dont know how to service clutches. I hope im not breaking any site rules by recommending this. Its just that i bought the tool set myself about a year ago and am VERY happy with the whole kit! Works perfectly..

[Kerick]

OK, when it sticks, does it have tight spots at certain points of the crankshaft revolution? Or does it feel equally sticky or tight all the way through a complete engine revolution? If its the latter, its probably time to get that primary clutch cleaned and serviced!

PS: dont try to dissasemble the clutch unless you have the proper puller to remove it from the crankshaft, and the proper tools needed to disassemble it once its off the engine....parts will go flying across the shop if you doo!

Well when it did stick I didn't even bother trying to pull it I didn't want to make it worse. As for the tool kit I'll check that out.

[RIDE-RED 250r]

Let me know and i can pm you a link for the clutch tools....