87 Enticer 340 compression

sagerider

sagerider

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Does anybody know what the compression for an 1987 Enticer 340 should be? I've had this sled for a few years, have no idea of prior history other than it looks real clean.

I'm getting 90 PTO and 100 MAG. I tested my guage recently against another it was reading about 8-9% lower. So this could be like 98/109

Thanks
 

First off they should be even. One being 10 lbs lower than the other shows it has an issue. Probably not major but something is up. They were not a high comp engine but a good one like yours should run around 120lbs on a cold comp test. They will start and run just fine at anything over 110lbs. When they are worn to the point that comp starts getting down below 110 they get progressively harder to start and this can be worse when the engine is warm. They are a VERY tough, reliable engine that has very little in the way of problems. Usually a light hone and a new set of rings brings them right back to life.

Good Luck,
Phil (opsled)
 
Thanks,

Yeah.. I knew the 10% difference is a bad sign. I havn't done anything to this sled but clean carbs and check jetting. It is the littlest critters, and gets lots and lots of pasture time.

Your right... it does get harder to start the warmer it is, and when its been running a lot is when it developes a bad low end bog, and somewhat often oil-fouls the PTO cylinder (the lowest compression cyl).

I'll order rings and gaskets for it. This is what I thought too, just was looking for more opinions.

Any other suggestions while I have it tore down? (another project... yipee)
 
usually 116". you can retro a 121" into it by moving the skid back. sry i do not have the specs for this.

when you are freshening up the motor, do yourself a favor and replace the crank seals. we have one at home that this happened to.
 
Thanks Maim. Yeah, starting to take stuff apart and found an oily looking broken "O" ring under the clutch... Hmmmmm Cyls look really good, just trying to find rings for it.

I found one set of rings, can't find another yet.
 
Well a re-ring did not fix the bog. I must have gotten too western pulling the carb out to do the overhaul. Had the squirt out on his maiden voyage today and the enticer nose dived hard. The low end bog was more like a low end growl with no clutch engagement. If you hammered it WOT from dead idle, it would either launch, or slowly rev up and take off. If you let off at all (like a seven year old always will) and then throttle up, it would bog completely out and stall. Put 20 miles on today, and fought it the whole way.

On the tear down I tried the trick of leaving all the crap attached to the carb, air box in, and just kinda wriggle it out of the way. I MUST have done something there, it was never this bad before.

Cyls did look awesome. Pistons looked okay, quite a bit of blow by. No major scoring at all anywhere. Cleaned everything up, honed the cyls lightly, re-ring and capoot. It was revving fine in the shop at 3,400 ft and track off the ground. But from trailer at about 5,000 and up... it was a fat, lazy, sick, old dog.

I'm going to pull the carb out and check it out. I got some manual on CD and hopefully its got good carb info.
 
Just checked: After the first 20 miles, compression is about 110 each side (I say just about because checking my guage against others it seems to be 10-15% low and it read 99 on each cyl).

Plugs: PTO pretty good, a little oily. Mag: Good

Fuel consumption TERRIBLE. showing 1/4 tank left (20 mile trip) and I'm guessing a quart of oil used. I think this tank only holds like six or seven gallons. It probably used 4 to 5. Its always been a gas hog, but nothing like this.
 
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Sounds like a stuck float, with that kind of fuel consumption. Be sure all the carb lines and cables are in sound position. Often times older hoses and whatnot can misplace or crack while being pushed aside. Does the exhaust seem to flow well. I ask because of the down time sitting aside you mention. I heard of exhaust acting as mouse houses.lol . Best wishes though. Let us know how it works out.
 
I just thought of a situation I had on my Enticer. The choke(fuel enrichment piston) could be stuck. My unit (85) has a fuel enrichment circuit that had lots of corrosion involved. Seized the small piston causing it to run real bad. One tell tell sign is that the choke flipper seamed real free moving. Not much detend. I then followed the cable to the carb and found that the cable wouldn't lift out as it should for disconnection. A couple pulls after soaking in penetrating spray loosened it enough for the removal and rebuild. Just a thought, yours may not have this feature.
 
One thing to think about is worn pistons also. Enticers are pistpn port motors, so the piston acts as a valve and closes the intake port when it comes down. When the skirts wear at the bottom of the piston, they don't seal as good and can cause a low end bog. I've seen pistons that were just "shiny" at the bottom cause a motor not to run right.
 
Thanks all. Well I thought I had it whooped. Work has picked up and I didn't get to it before the little guy was ready to ride again. I did some adjusting with the air screw/ slow adjuster that is outside and on top of the carb. After tuning it per spec, the bog seemed gone. I couldn't get it to bog... in the shop, only using the brake as load.

Got on the trail, about three miles up and the bog returned. Messed with that adjustment some more, would run okay for a little bit, then bog out again. All on the low end when the little man is frigging alot with the throttle.

Hopefully I get to it this week. I did change out all the fuel lines already. I'm going to pull the carb and check float, jets, and all the cables and such while I'm at it.

As for the piston skirt thing... only way to check that is to check the dimensions of the piston? That would probably be a summer thing at this point.

Thanks again for the input, I'll reply when I get all this done and back on the mountain for testing.
 
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