vector engine issues

[Metallicat]

Hey Roger, did your dealer or Yamaha ever say what caused your valves to go bad? Did you actually burn your valves up?

I used to have to change the exhaust donuts on my 2 stroke sleds every 3000 miles but then again it was only like a $15 / 5 minute repair job. The grafoil exhaust seals deteriorate rapidly with any type of vibration or movement.

 

[RSVECTORFREAK]

I haven't touched mine in 4600 miles......Engine runs like the day I bought it..

 

[Tfin]

I haven't touched mine in 4600 miles......Engine runs like the day I bought it..

Ditto that!

 

[Stu]

...From everything that I have heard here, and by Yamaha, engine problems are rare in the 120h.p. Yamaha's. Frankly, I think Yamaha is lying, and the number of engine problems is much greater than they are admitting to...

This is just your opinion, and by the troubles you have been having with your sled I understand why you would feel this way...HOWEVER, the lack numbers of engine problems that have been reported seem to support just the opposite.

...The amount of oil that an e-tech uses per winter, will be a lot cheaper than 1 oil change. And with my experience in snowmobiling, 4-strokes are not quite there yet...

It appears that you have made your choice. May you have better luck with your new brand...

 

[Groomerdriver]

I haven't touched mine in 4600 miles......Engine runs like the day I bought it..

Ditto that!

Have you had your donuts checked or checked them yourself? My sled runs great too, but towards the end of last season, I could smell burning oil coming from the tunnel when we stopped. Thought I had a leak after they changed the jack and main bearings.

Turns out the problem was that the donuts were bad and exhaust was mixing with the snow resulting in the oily smell.

I clean my clutches too but had to replace weights and rollers at 3600 miles. How are yours?

What I'm pointing out here is the Yami 4S engines don't seem to have a real solid pattern as to when stuff wears out. You need to be listening to your sled and looking it over from head to toe.

 

[RSVECTORFREAK]

I haven't touched mine in 4600 miles......Engine runs like the day I bought it..

Ditto that!

Have you had your donuts checked or checked them yourself? My sled runs great too, but towards the end of last season, I could smell burning oil coming from the tunnel when we stopped. Thought I had a leak after they changed the jack and main bearings.

Turns out the problem was that the donuts were bad and exhaust was mixing with the snow resulting in the oily smell.

I clean my clutches too but had to replace weights and rollers at 3600 miles. How are yours?

What I'm pointing out here is the Yami 4S engines don't seem to have a real solid pattern as to when stuff wears out. You need to be listening to your sled and looking it over from head to toe.

My donuts are fine had dealer check them end of last year and I added a clutch kit to mine no problems there either in the last 3 years but I'm running polaris weights and springs also.

 

[Groomerdriver]

I haven't touched mine in 4600 miles......Engine runs like the day I bought it..

Ditto that!

Have you had your donuts checked or checked them yourself? My sled runs great too, but towards the end of last season, I could smell burning oil coming from the tunnel when we stopped. Thought I had a leak after they changed the jack and main bearings.

Turns out the problem was that the donuts were bad and exhaust was mixing with the snow resulting in the oily smell.

I clean my clutches too but had to replace weights and rollers at 3600 miles. How are yours?

What I'm pointing out here is the Yami 4S engines don't seem to have a real solid pattern as to when stuff wears out. You need to be listening to your sled and looking it over from head to toe.

My donuts are fine had dealer check them end of last year and I added a clutch kit to mine no problems there either in the last 3 years but I'm running polaris weights and springs also.

Polaris clutch parts have a history of being VERY durable.

Care to share what Poo parts you put in and what were the results?

 

[Tfin]

I haven't touched mine in 4600 miles......Engine runs like the day I bought it..

Ditto that!

Have you had your donuts checked or checked them yourself? My sled runs great too, but towards the end of last season, I could smell burning oil coming from the tunnel when we stopped. Thought I had a leak after they changed the jack and main bearings.

Turns out the problem was that the donuts were bad and exhaust was mixing with the snow resulting in the oily smell.

I clean my clutches too but had to replace weights and rollers at 3600 miles. How are yours?

What I'm pointing out here is the Yami 4S engines don't seem to have a real solid pattern as to when stuff wears out. You need to be listening to your sled and looking it over from head to toe.

Had the dealer check mine as well and everything speced out fine.

I'm also running an Ulmer stage III clutch kit, so I have new weights, rollers, springs and helix.

Just a hunch, but I'd be willing to bet there are more 120 4S engines out there without donut failures than with them. That of course doesn't negate the pain in the azz if you're one of the few with a failure.

 

[Zoomsplat]

I've been a technician for the past 20 years, the last 6 or 7 of which, have been with Yamaha. I've seen 2 of the 120, 4-stoke engine failures. Both from the same guy. Maybe 1 or 2 donut replacements. With 6 months of winter, I see quite a few sleds in a season. They're pretty good odds in my books. My '06 Nytro also has a MCXpress turbo on it. No problems, so far. Only time will tell, I guess.
I'd like to know what other manufacturer can boast those kinds of numbers. No matter what you ride, there will always be exceptions and there will always be problems. It's just the nature of the beast. Look at what they go through. Keeping those numbers low, is the key.

 

[BETHEVIPER]

i would be surpised if the obove clutch parts replaced were really needed, i redid two rx1 clutches last year with over 10,000 miles on both and the rollers were good, all they needed were new bushings in the weights and side washers, did the Oring update at the same time.

 

[Groomerdriver]

i would be surpised if the obove clutch parts replaced were really needed, i redid two rx1 clutches last year with over 10,000 miles on both and the rollers were good, all they needed were new bushings in the weights and side washers, did the Oring update at the same time.

you refering to my post? if so...yea..my sled over revved to 9200 for no reason...gas mpg went to 12 because clutch was over revving....weights had moderate (I would call hondo's wear "severe") grooves worn in them.

uh huh....I put $400 in my clutches because I had nothing else to do with the $$$

 

[nb-attak]

my freind bought a used 06 nytro. He has owned ski-doos all his life. Our first trip this winter was saturday. all was great, nice trails. at 40 miles we stopped at a camp, he noticed a small but unsual ticking sound, barerly noticeable. The motor was smooth and quiet before. One mile later at a junction on the trail while idling his headlight blinked, then the motor stopped. We removed his belt to tow the sled. Then i tried turning clutch by hand to see if the motor was seized. I could only turn the clutch one way, when i tried to turn the other direction i couldnt for the life of me turn a single millimeter. He s bringing his sled today to dealer. Just curious what anyone thinks. Im hoping (wishing) its a faulty starter thats locked , since the motor turns only one way. Not likely though since motor was running. Its hard to imagine a four stroke yammy motor going down like that, the sled is mint with only 1200 miles or so.
But i guess its just an engine, anything can happen

 

[Groomerdriver]

my freind bought a used 06 nytro. He has owned ski-doos all his life. Our first trip this winter was saturday. all was great, nice trails. at 40 miles we stopped at a camp, he noticed a small but unsual ticking sound, barerly noticeable. The motor was smooth and quiet before. One mile later at a junction on the trail while idling his headlight blinked, then the motor stopped. We removed his belt to tow the sled. Then i tried turning clutch by hand to see if the motor was seized. I could only turn the clutch one way, when i tried to turn the other direction i couldnt for the life of me turn a single millimeter. He s bringing his sled today to dealer. Just curious what anyone thinks. Im hoping (wishing) its a faulty starter thats locked , since the motor turns only one way. Not likely though since motor was running. Its hard to imagine a four stroke yammy motor going down like that, the sled is mint with only 1200 miles or so.
But i guess its just an engine, anything can happen

If the track would turn that eliminates a blown chain. My guess is that something let go on the lower end of the motor.

But I hope I'm wrong!!! Keep up posted!!!

 

[nb-attak]

Dealer just confirmed that the starter was the problem. Everything is being replaced at their cost.
I should have waited before asking questions on this site. Rumors spread way too quickly on internet. Im glad its not major though. We just might have another blue member,

 

[BETHEVIPER]

all you guys motors suck and are going to blow up, you should buy my low milage motor so you will have a spare. not going to use it anymore. you guys scared me and im going with a apex now.