Area 51 Project - Duncan's 2017 Yamaha VK540:

 

Long Term Review

 

I’m the owner of a 2017 model VK540. The sled was built in August 2016 and was part of the first shipment of these sleds to the North West Territories. The snowmobile was delivered in January of 2017 to a tiny community called Ulukhaktok on Victoria Island, NWT. There are no roads into the town so it was delivered via air from Yellowknife on a First Air ATR42 Passenger/Cargo plane. The temperature on the day of delivery was -37 (this is without wind chill. I’ll quote temps several times during this review and I won’t be going off of wind chill at all, just what the mercury says on my thermometer), and it stayed that cold or colder for the first four weeks of the sleds life. At the time of writing (April 2019) the machine has just over 1400km on it. I’ve condensed my overall impressions into what I consider to be Cons, Pros, Modifications that I’ve found useful, and a short summary. These are based on my uses for the sled, and I encourage anyone reading this to formulate their own opinions.
 

 

CONS:
The biggest con with this machine is the way the single carb affects fuel delivery in very cold temps. While I like a single carb machine for ease of maintenance and adjustment, the drawbacks are apparent when it gets very cold. This is exacerbated by the Yamaha VK fuel pump, which while simple and fairly robust, isn’t known for being the highest volume pump on the market.

Suspension is a basic up front with two pillar shocks and integrated springs. It is narrow and it isn’t sporty. This is also a pro for getting through heavy brush, but nowhere near as controllable at speed as a modern suspension.

 

 

The battery they sent with this model was a basic Yuasa lead-acid battery. I wouldn’t keep this battery on an ATV, let alone a snowmobile designed for cold weather. They may as well not have put a starter on the machine with this battery and it failed almost immediately. I replaced it with a similar-sized XS power brand battery several weeks after delivery and it’s been performing well ever since.

 

 

The head bolts on this sled have come loose twice, once shortly after delivery (part of the recommended break in that I forgot to check) and again after just over 1000km. I find on this machine that just a few pounds off of torque spec causes problems for fuel delivery, likely made worse by the single carb design. I make it a habit to check the head bolts every time I bring it in to grease it, but the problem hasn’t surfaced again. Since it’s only happened a couple of times I can’t say if it’s a design flaw in the engine, or if it’s just a fact of the engine going from -30 and colder up to operating temperature and back again repeatedly, could be affecting the lock nuts and how they interface with the cylinder head.
 

 

I have had an issue with ice in the fuel pump. In fly-in communities in the far north, our gasoline is delivered once a year via fuel barge. The fuel companies do a very good job of getting clean fuel in, but we still get water in our gas, and it’s made worse by the constant blowing snow. My sled got to the point where it wouldn’t start unless I pressurized the fuel tank to push fuel through, and even then it would stall out after several seconds. I was forced to tow it into a garage, thaw it out and add some fuel de-icer to burn out the water. A common issue with carbureted sleds, especially up north of 70, but still an issue and needs to be mentioned.

 

 

PROS:
The wide track and wide stock ski’s make this sled very hard to get stuck, something I haven’t managed to do in over two years of riding this machine. While this is pretty much standard for most wide tracks, I still find it worth mentioning.

Fuel tank is 44L, not huge for a utility sled, but decent sized. It has an old school float style fuel gauge/cap that is reliable in all weather. It’s also calibrated very well, and ¼ tank still leaves the rider with about 15L, which is a nice insurance policy.

 

 

The belly pan is very low. Many riders, especially in the tundra, have experienced a hard time seeing dips and bumps in the trail. This is very bad on overcast days and I often have a hard time seeing drifts and small ridges in the snow. With hard packed snow on a standard machine this can lead to some rough riding when you hit a drift at speed. The VK bottoms out fairly quickly but the included plastic full length skid plate just sucks up the bumps.

 

 

The power and acceleration on this machine is surprising. It is by no means a performance sled, and I am by no means a performance rider, but acceleration to 80k is very quick. After 1400 hard and very cold kilometres my compression is still 117/119 PSI, which for a sled that is spec’d for around 100psi out of the factory I find to be quite impressive. Acceleration and towing is better than any comparably sized Skidoo or Polaris two strokes I have used. The hood opens up like a sled from the 70’s, and there’s lots of room under there to get at the engine and belt. The belt comes off quickly and without tools. These two features alone were a huge selling point for me. Not to mention the old school under seat storage and the included large rear basket.
 

 

 

The VIN sticker says “made in Japan” and it may be one of the last “actual Yamaha” snowmobile on the market. Fit and overall construction is very good. Most of the fasteners are small powder coated bolts with lock nuts, something I don’t see on many new sleds. The machine comes standard with factory heated grips and thumb warmers, LED rear tail light, back rest and rear handles, a generous windshield and the aforementioned large rear basket. I added a set of Gear Grips to hold a rifle out back and I haven’t wanted for anything else. When compared to a similarly spec’d Skandic, I found the price tag to be quite a bargain
 

 

Mods:
In the environment this machine is used, severe cold is the enemy. Like anyone with a 40 year old back, I much prefer to start this thing with a key rather than pull it over. In order to do that year round, I added a few things. I already mentioned swapping out the battery, and I also added a battery maintainer and a battery blanket. The battery compartment is tight, especially with the aftermarket battery which is ever so slightly larger than stock, but there is still room to wrap a battery blanket in there. There is also an aluminum panel under the hood with the electrical accessories mounted. There is room to put a battery tender there, so I mounted a small “battery tender” brand maintainer using self tapping screws. It’s as solid as the day I put it on. I ran the wiring for it just outside of the hood along the cage and then back in by the battery compartment. Both plugs for the maintainer and the battery come out of the left side vent and are easy to plug in. I usually plug it in during the winter, and at -25 and colder I make sure to do so. The XS power battery has failed only twice. Both times it was not plugged in and it was -33 or colder.
 

 

Fuel Delivery/Starting particulars:
Like any two stroke carbureted machine, this sled can be a finicky beast when cold. When it’s really cold, the issues with the single carb and Yamaha fuel pump seem to need a bit more care than something with twin carbs. I’ve got a bit of a “system” that I go by for this machine, and so far it’s been pretty consistent.


At -15 to about +5:
3-5 gentle pulls on the cord to loosen up the cylinders, start it with key on full choke. Fires up immediately and can switch to half choke in 3-5 seconds. Then to no choke in about another 30 seconds to a minute or so.


-25 to -15:
3-5 gentle pulls on the cord loosens up the cylinders, then start it with the key. May take up to 5-6 “tries” with the key, keeping the starter hits short to go easy on the starter. May fire up on magneto side first depending how cold it is. Hold it on full choke until both sides fire up. Usually takes 3-5 seconds.
 

 

 

-25 and colder:
3-5 gentle pulls to free up the cylinders, followed by 5-15 good hard starting pulls. At -30 and colder you’ll need all of those 15 pulls and then some. This is where a priming pump would come in handy. Essentially I am pre-priming the carb so that the starter doesn’t have to. The sled may even start during this “priming” sequence. I then switch to the starter, assuming my battery is good. Once it fires up, it usually hits the magneto side first again before both cylinders fire. Again, the key here is holding it on full choke until both sides fire. Very rarely, if it's extremely cold and the machine hasn’t been started in a while, the pto side will be especially stubborn. I have on two occasions in the current life cycle of the snowmobile had it stall out on the mag side because the pto side didn’t kick in. When I restarted it again on full choke, both sides fired up.


 

Note: this starting sequence is only for the first start of the day. Once it’s been started once, I use the key and both cylinders fire up as normal. Seals shrink in the cold and the fuel delivery process gets less efficient as the mercury drops. Something that isn’t a problem at -15 is a problem at -33. I personally believe that this sled could desperately use a fuel primer bulb or pump from the factory and this would really improve starting in extreme temps. I haven’t installed one yet, but it’s on my to-do list. It’s worth noting that I keep the idle on this machine higher than recommended. There is no tach on this sled, but I believe instead of the 1200rpm, I am more like 1500+, possibly 1800rpm. It shortens the life of the machine no doubt, but it also starts and idles better.


 

Summary:
Overall I am very happy with the VK and I would buy one again. The flip up hood, two stroke 535 power plant combined with the LED lights and modern accessories are the perfect blend of old and new technology. When this one wears out I’ll be sure to take a hard look at the newest Skidoo ACE models on the market, but as long as I use a machine in northern climates I’ll be very happy to rip along on my oil burner.

 

Cheers, Duncan Marsh

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