1986 Argo 18hp Magnum Engine, what should the compression be?

[msta999]

Hi all, I picked up the above machine and have been getting it running. I put a new carburetor on it and it runs, but it is real rich and looses power when turning in high range. Also, I was checking the compression and I have 60/65, which seems low to me, but I don't do a lot of work to small carburetor engines. I sent a email to Itractors, who I bought the carb from, asking about the correct float level.

I have downloaded the service manual and it tells specs like bore displacement, compression ratio, but there is no mention of the compression spec.

I hope someone here can help.

Thanks.

[msta999]

I don't know how accurate this is, but this is what I found to determine what the compression of an engine cylinder should be:

https://www.reference.com/science/convert-compression-ratio-psi-825aedc74e6b59d7

Acording to this, mine should be about 88 psi, still lower than what I thought it would be, but it gives me something to go by. So at 65 psi, mine is about 73 percent of what it should be......guess I may be pulling the engine out in the fall, but I don't think even that will be enough to pull a trailer with lumber or even a moose......maybe in low range....

[ARGOJIM]

If you have it running and have never had an 8x8 before, other than the richness, I would take a good part of a day and just run it around. Getting used to a 8x8 of that era takes a little seat time, bogging down at lower rpms is normal, remember to throttle more as you are turning in most situations and try not to turn from a dead stop.
After a day in it you may find there is nothing wrong and just the nature of the older Argo.

[Gordy67]

After doing a compression test recently on the Kawasaki, I’m now keen to know what compression my old Kohler has in my other Argo. It’s a very sweet running engine and the Argo was shown a lot of love from the previous owner and local Argo dealership.
I’ll report back in 24hrs....

[msta999]

If you have it running and have never had an 8x8 before, other than the richness, I would take a good part of a day and just run it around. Getting used to a 8x8 of that era takes a little seat time, bogging down at lower rpms is normal, remember to throttle more as you are turning in most situations and try not to turn from a dead stop.
After a day in it you may find there is nothing wrong and just the nature of the older Argo.

I took it out a couple times for a couple miles, in areas where I do a lot of turning I noticed I can smell hot brakes, but it goes away when I get on the straight aways.

[msta999]

After doing a compression test recently on the Kawasaki, I’m now keen to know what compression my old Kohler has in my other Argo. It’s a very sweet running engine and the Argo was shown a lot of love from the previous owner and local Argo dealership.
I’ll report back in 24hrs....

That would be great! Thanks.

[msta999]

I have been watching the youtube videos on argos and it looks like most have tracks, looking at these I'm thinking I could get rid of my bearcat snowmachine and not worry about replacing my 6X6 side by side and just get a newer argo with tracks. I seen some with a bed for hauling stuff on the rear which is what I used the side by side for....How do I tell which tracks will fit my machine? I came across some Gen 2 supertracks with ice cleats. 18 in wide.... anyone put tracks on an older 86 argo before?

Oh, I am sending the carb back, it is running too rich, I'll check it out again when the new one gets here.

[Gordy67]

As promised I did a compression test on the Kohler, it’s the KT 17hp model I have and not a lot different to the 18hp Kohler Magnum
I got 75 psi on both cylinders with a warm engine.
Unless anyone can turn up an engine spec that lists the compression parameters, I guess it’s all we’ve got to go on

[msta999]

Yeah, I was thinking mine is kind of worn. If I decide to rebuild it, I think I will have it bored out to the 20 hp, I read it is the same block.....have to research it more.

[anotheramature]

My manual says 90lbs with a 15% variance.

[msta999]

Thanks, that is good to know.

I picked up a parts Argo, with a better tub, bearing and chains, the engine has almost 95 lbs compression so I took mine apart and put the parts engine, transmission on the new tube with the rest of the parts from my old argo. I have it together and it runs good, has lots of power for a few seconds then the gov. backs the throttle off. The Gov was stuck and I worked it and it came free, Also I had the throttle cable spring too tight, so I put the sping in the end hole and moved the throttle cable closer to the spring and that made it better, but when at full throttle, it will still back off the throttle.

[msta999]

after some reading, sounds like it might need the gov adjusted, I'll try that.