MM700 dies after running perfectly

[BlindChicken]

I recently picked up an 01 mountain max 700 for cheap and took it out to the snow for the first time yesterday. It always ran great on the trailer and for the first ten minutes ran flawlessly.

After that initial ten minutes it would act like it is loading up, lose power, sputter and die. It was like I ran out of gas. If I wait a few minutes it would start right up and run great for a minute or two then do the same thing.

My thought is either fuel delivery or electrical but thought I would get some feedback before I tore it down.

Mechanically I am pretty sure the engine is fine. Compression checks and fluid inspections are good.

I have not pulled the carbs on this yet so I am leaning toward that but it sure runs great at first.

Any thoughts?

 

[roudyroy1]

if you flip the choke when it dies does it clear up? sounds like fuel delivery. i would start by cleaning the carbs, especially the screens under the seats.

 

[Vincent]

Just to add to roundyroy1 list,
Fresh fuel and filter. Filter in the tank btw.

 

[A couple of bucks]

Electrical components.... such as plug caps and coils lose their ability to insulate the electrical impulses over time. Heat exaserbates this problem. This means that a cold or warm engine might run absolutely great. But once the insulation in that compromised component gets hot, the internal insulation swells and the electrical impulses don't go to where they are intended to go.
Plug caps are cheap enough and yours are more than likely way over due for replacement. I would change these out along w/ a tank fuel filter and re-evaluate from them.

https://totallyamaha.net/showthread.php/75436-Change-your-sparkplug-caps?highlight=Tb05ema

 

[BlindChicken]

Another thing that makes me think it is carbs is when the sled sits for a couple days I have to prime it to get it to start. Once warm it fires right up.

 

[A couple of bucks]

Sounds like fuel is siphoning back into the tank.

 

[super1c]

sounds as if it could be a bad stator also? Do the lights dim at all when this is happening? The stator overheats and shorts out. You let it sit, the stator cools and works again till it heats up the shorts and shuts it down.