One Mouse totals my sled!?? Excel V help needed!

ws6transam

ws6transam

New member
Joined
Sep 4, 2007
Messages
69
Age
59
Location
Haslett MI
I'm totally new to snowmobiles and finally got around to getting myself one... A vintage 1980 Yamaha Excel V (EC540) for $300. All it was supposed to need was a carb cleanup, since it no longer started. However when I attempted to roll the engine over, it would only turn about 1/2 a revolution then stop. Something else was amiss. The cylinders themselves looked great: No ridge, no rust to be seen anywhere. However there was this huge mouse nest inside the fan shroud, and it even packed seeds into the stator! It looked as if I was going to have to pull this engine out and have a look.

First, I started with removal of the CVT belt. Then I removed shroud around the stator. Then I disconnected the carbuerator, but the choke rod was absolutely stuck into the housing! I worked the carb out of the intake manifold boot and this big gob of greenish-orange fuzz fell out of the intake manifold....

Unbelieveable.

Somehow, incredibly, a mouse ate its way through the air filter, and then managed to wedge enough crap into the butterfly valve of the Kehin carbuerator to hold it open. It then proceeded down the intake and wedged a bunch more crap through the reed valves. It then made its nest in the intake and used the reed valves as it's personal outhouse. The reed valve cages are RUSTED, the carb may be totaled as I cannot unstick the choke rod: I'll have to cut the cable. Certainly the venturi surface is pitted with all of an eighth-inch coating of smooshed & smoothed mousie droppings. A lamp and mirror reveal connecting rods that are coated in light rust, and there is discoloration on the cylinder walls. One would have to guess that the rod bearings are also toast. This engine most likely needs a new carb and a total rebuild.

Is it even worth reviving this snowmobile?
 
them were nice ,reliable little sleds. that really stinks ! mice have cost man so much grief and money by turning machinery into homes.i would take in to consideration the condition of the sled and then tear it apart and figure out what it is going to cost to rebuild and even make sure you can still get the parts which i think is a good chance you can. or you can find a good running used engine, which should not be a problem,as they were plentiful but in the end the choice will be what you want to do so good luck.
 
This snowmobile has no dents, and minimal, if any, rust. Everything is there, and there is only a small tear in the seat. The left ski is a bit bent up, and the mileage is a tad under 5000 miles. The belllypan is greasy. That's about it.

ExcelVa.jpg


The engine is on the hoist tonight, and it doesn't look to awfully bad. At least it turns 270 degrees, then it locks up solid. It's probably hanging up on a pile of mouse crap at the bottom of the crankcase.
ExcelVg


The six or so pictures are in the gallery.
http://ws6transam.org/Gallery/Snowmobile-project/ExcelVb
 
Okay, then engine is disassembled. I had to beat one pison out of its bore with a wooden rod, lost my grip and shattered the skirt off the piston. Unfortunate.

Now, does anyone know where I can get replacement pistons??

It looks as if the bottom-end damage is confined to a rusty spot on the counterweight, and one bearing. It was lucky that it was the closest one to the stator. I used a fine-tip brazing torch to heat up the rusted balls in the bearing, which then transferred their heat into the race. It was enough to expand the bearing and I was able to lever it off the crank without damage. I'll have to wire-wheel the counterweight, then dip everything into a bath of solvent to get the crud off. The crank case is full of black stuff: Presumably smushed mouse poop. I can't f'in believe the mess. Luckily it was confined to one cylinder.

So it looks as if I need a bearing, a new seal at the stator end of the crank, and a top-end rebuild gasket kit, plus one piston and a full set of piston rings. The cylinder appears to need only a hone, but I still need to measure for out-of-round, taper and eccentricity.

Oh, and I need a new carb and choke cable, I think. Anyone have a suggestion on what to do there?
 
So far, it looks as if I need about $400 worth of parts to get it running again. So that brings the tally up to about $750, excluding title transfer, rego, etc. etc. , not including the re-stitch of the seat which I might attempt in order to complete the revival.

Is this snowmobile really worth that, in running condition?
 
I had one of those, a 79 Excel IV 540. They are exactly the same as an SRV 540 engine wise. I just seen a bunch of SRV parts on Fleabay today.
 
Thanks for the tip!

...Yeah I'm into it now. It's looking really good in terms of getting this thing going. I've cleaned that chassis and it's pristine with no rust. The crank case is back together, and only one bearing was totalled: The end one, just behind the stator. Woo hoo, no crank split necessary!

Now I just need to get some tygon tubing for the fuel system, rebuild the carb, reassemble the top-end, and tidy it all up. The future's looking bright for this machine. I hope to have it going before winter.
 
ws6transam said:
Thanks for the tip!

...Yeah I'm into it now. It's looking really good in terms of getting this thing going. I've cleaned that chassis and it's pristine with no rust. The crank case is back together, and only one bearing was totalled: The end one, just behind the stator. Woo hoo, no crank split necessary!

Now I just need to get some tygon tubing for the fuel system, rebuild the carb, reassemble the top-end, and tidy it all up. The future's looking bright for this machine. I hope to have it going before winter.
Click to expand...


SRV parts are similiar but not all are the same. Your 79 was the first year of production for the 540 and the Exell engines were detuned in comparison with the SRV. There were alot of differences and also alot of changes made in the first few years of production so make sure whatever parts you are buying for it are compatable.

Do yourself a big favor and buy OEM Yamaha line to replumb any fuel or oil lines. It is not that much more money considering all the work you have gone through already and I have found most aftermarket line to be junk in comparison. The ID and OD of most aftermarket line is wrong, it is not as flexable so routing can be an issue, it doesn't fit the nipples correctly so leaking can be a problem and the OEM clamps won't work.

Phil (opsled)
 
Glad to hear its coming along. Been thinking about finding something for cheap $$ just to bomb around with a little myself. Out here in Mass though, alot of winters we dont really get enough snow anymore.
 
Happens all the time.... the cure?? some 1/4" galvanized mesh wire from the hardware store. Cut a swatch to cover the airbox intake... RTV to hold it in place... black spraypaint makes it look factory. I use it in EVERYTHING!!! sleds, cars, bikes....
 
Hi everyone,
Just a note to tell you that this afternoon, the snowmobile started right up. I did a complete rebuild, and had to tear everything apart except the track. It's all together now, and starts instantly with a turn of the key. Sweet! I can't wait for snow! It seems like a lively little engine, too! Very throttle responsive.

I even got a trailer via craigslist: A nice lightweight aluminum trailer, 8 x 10, with torsion axle and a front salt shield. Unfortunately, after the necessary repairs to the axle, it cost me more than the two snowmobiles combined.

Ah well, So far the investment for both snowmobiles (including trailer) is standing at $1900.

Also, I tossed a few mothballs into the outer chambers of the airbox. It was an easy fix, and Naptha vapors, though toxic & repellant to mice, is harmless to engines.
 
We just got our first snow last night. There's just enough to cover the grass, and I probably did about a dozen tight circles with the Enticer 340 in the back yard until the snow began to mix with mud. Fun stuff! My wife was looking out of the kitchen window, just laughing at me! I have a small enough back yard that I had to keep getting off and pulling the front-end around to clear things like the swing set, garden shed, garage wall, and deck. Now all we need to do is replace that trailer tire and buy some helmets and we'll be all set for our first exposure to snowmobiles!
 
ws6transam said:
Hi everyone,
Just a note to tell you that this afternoon, the snowmobile started right up. I did a complete rebuild, and had to tear everything apart except the track. It's all together now, and starts instantly with a turn of the key. Sweet! I can't wait for snow! It seems like a lively little engine, too! Very throttle responsive.

I even got a trailer via craigslist: A nice lightweight aluminum trailer, 8 x 10, with torsion axle and a front salt shield. Unfortunately, after the necessary repairs to the axle, it cost me more than the two snowmobiles combined.

Ah well, So far the investment for both snowmobiles (including trailer) is standing at $1900.

Also, I tossed a few mothballs into the outer chambers of the airbox. It was an easy fix, and Naptha vapors, though toxic & repellant to mice, is harmless to engines.
Click to expand...

Nice work.

:letitsnow
 
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