Linked to How To thread.

 

Very nice post I'll have to inform my Dad about this.

 

VES Assembly

Insert the guillotine valve into the housing, and align the washer, bellows, and cap. Lightly coat the bellows with fresh oil Use blue loctite on the threads, and torque the bellows cap to about 6-8 ft. lbs. DO NOT OVERTORQUE.

Install the correct spring onto the bellows cap, install cover using two bolts. Use blue loctite, torque 4-6 ft. lbs.

These guillotines are the newer stainless steel parts, you can see the hollowed areas that help reduce the weight of the valve. If your valve has these intents, they are not aluminum.

Insert the valve back into the engine. The guillotine is eccentric, it will only go in one way. Do not force it! Using blue loctite, torque the longer VES housing bolts 9-12 ft.lbs.

A few more notes...

There are different ways to clean the guillotines. If you scrape the carbon off, be very careful not to scratch the guillotine. A green scotchbrite pad works well after removing the majority of carbon build-up. The steel valves are a lot more robust and do not damage as easily as the aluminum ones. Some guys have had success using oven cleaner to get rid of the carbon, I have not tried that, but it may prevent damage to aluminum guillotines.

If you do not need to replace bellows or springs, you can remove the bellows assembly and clean the guillotine without completely disassembly. The guillotines do not need to be spotless; removing the majority of the carbon and making sure they are smooth will ensure proper operation. I still like to disassemble mine to ensure there are no holes or damage to the bellows, and that the spring is intact.

 

VES Assembly Question

Do you need to apply any adhesive or sealant to the bottom perimeter of the bellows to ensure an air tight seal? When I took apart the valve assembly the bellows seemed to stick to the valve base (not the plastic cap).

 

Pretty motor!

 

No sealant is required. It was probably sticking because of cooked oil.

That motor had just had the cases machined, new crank with wide PTO bearing, new VES valves, bellows, and springs, new pistons (just because) and then it got kind of toasted in the fire. Sigh. I got 400 miles on it, though The engine made it into another sled and is still on the snow somewhere, too!

 

So what happened with this fire your talking about i have always seen it in your signature but never knew the story.

 

Ves

Alright, thanks. Looks like I need new bellows; I have air coming from the openings on the caps when the engine is idling. Probably just worn bellows causing this? Looks like they've moved to a rubber bellow instead of the previous type.

 

air should come out, as long as there is no smoke or oil, it is just the valve moving up and down, normal opperation

 

The valves move up and down with every cycle? It was my understanding that they didn't open until 6k rpm.

 

Hey Dan these are the exhaust valves right? I cleaned mine last year and I'm sure they are due. When I go to bolt the covers back on should I torque it to 9-12 ft pounds? I did not pay much attention to torque when I put them back on. I have that black sludge crap leaking out of the cover from where it should seal so will be picking up a couple gaskets as well. What ultimitley happens if you do not clean them?

 

Take a look at the bellows. A few years ago I had a hole in one of them and it robbed me of anything over 70 mph. I had oil blowing out of the hole on top of the cap so I took it apart and noticed the hole (and then paid $40 to a local to take used parts off of his sled so I could keep riding )

 

Because a 2-stroke cylinder doesn't have a valve train, the intake and exhaust is done by ports in the cylinder. A manufacturer can design a port that is good at low RPM for good low end torque or good for high HP at the top end, but not both. The VES valves make the engine act like the cylinder is ported for low end torque but when the RPM gets high enough, the pressure coming to the bottom of the bellows pushes the VES guillotine valve out of the way so the cylinder can have the high speed performance too. Gunked up valves will rob you of top end and there will be a really big decrease in speed and HP above the point where the valves open (usually 6000-7000 RPM, depending on what spring you have in the bellows).

You want to keep the valves clean to ensure they will move as necessary to give you both low end torque and high end HP.

Like bigvander said, if you have oil coming out of the hole in the VES cap, the bellows has a hole. It's also a good idea to keep a couple of gaskets around, they're not expensive and don't take up much room in the tool box

 

Bellow Note

I forgot to put oil on the bellows before I reinstalled them (the old design will not seal unless you put oil on them). They seal now! No air is coming from the cap holes and the suction test works.

 

don't forget to clean the little port holes in the motor

 

okay guys, one thing I'm confused on is whether or not there should be air coming out of the VES valve assemblies when the engine is idling...
I cleaned mine on my 700 and the bellows looked to be in good shape, I applied a little oil to seal them, but when the sled idles, I can feel "pops" of air coming from the hole in each plastic cover...i don't see any oil or smoke coming from them so I just assumed it's normal...I'll pull the covers off again when I get a chance and have another look at the bellows

 

Shouldn't be any combustion gas coming out of the VES assembly. The bellows should trap any gas/oil below the bellows. When you take the VES cap off, the top of the bellows should be clean, the bottom will be filled with black oil.

How are the springs? I'm wondering if the spring is shot and what you are feeling is the bellows moving up rapidly with no spring resistance, forcing a bit of air up as it comes. Just a thought and a SWAG

 

what did you use to get the old oil off or did it rub off

 

I have the same issue after everytime that I clean them but it only lasts for a few minutes. Once the engine warms up they seem to seal. Maybe add a little more oil to the bellows and ride it for a few minutes.

 

Yea the old oil just rubbed off, I didn't use anything that would damage the bellows.
The sled has under 3000 miles; the springs felt like they had plenty of resistance when I had the VES assemblies apart, and the bellows looked to be in good shape.
I don't usually take the valves completely apart because I was told that the bellows nut breaks easily but I guess it would be okay.
For what it's worth, I might just replace the springs and bellows and see if it makes a difference.

 

If your bellows are dark green colored, it would be a good idea to replace them. The new ones are orange and are a bit stronger.

 

have got to ride the sled before and after cleaning and will cleaning make a big difference or was it just something to do in ur spare time

 

If the guillotines get carboned up, they will open sluggishly or not at all, which will affect the power at wide open. If you can't get past 7000 rpm, it's likely the valves are not opening fully.

 

ves guillotines

i was wondering if the curved side on the guillotin should be on the top or be on the bottom because i didnt pay attention when taking out which way it was but the guillotine can go in either way could someone please help

 

i was wondering if the curved side on the guillotin should be on the top or be on the bottom because i didnt pay attention when taking out which way it was but the guillotine can go in either way could someone please help

They only go in one way. The guillotine is offcenter on the stem.

 

I was loaded up in a 27' enclosed trailer with 4 sleds full of fuel, for a ride the next day. I had a catalytic heater running in the trailer, which was parked in front of the house. The trailer was full of ice and snow and I wanted most of it gone so some people new to snowmobiling could use the sleds the next day on a group ride. I checked it on the hour for 3 hours, some time between hour 3 and 4, fumes from a gas can on the 04 800 escaped and ignited, burning up the 4 sleds and the trailer.

I was on vacation that day and "my" guys had to come help me put out the fire. I don't know which was worse

 

man, that would be terrible. You get any help from insurance?