Learn something new every day - compression testing.

[SIIaCanuck]

I just dropped into Centrepoint Performance near Leduc yesterday and discovered, amongst other things, a JD sled museum (54 sleds ish?) of sorts.

The owner was a JD dealer from '71 until the end and his mechanic started with the Fire series sleds and is still with him. He's got a beautiful '84 LF resto in the back shed in the final stages of completion.

Anyway, the place is a goldmine of parts and, more importantly, info on JD sleds. I learned that the very first '80 Liquifires came out with different carbs that were subsequently re-called and replaced. Not sure which carbs they were but I didn't know this tidbit.

I also found out not to trust compression tests using a tester with a 12-14" hose. Compression volume in the little 440 cylinder is too small and the volume of the hose makes a big difference. Obvious I suppose if I'd thought about it. However, they recon that my 107/114 compression with my 14" hose is probably over 120 per side with a 1.5" stubby hose.

Good news on compression then.

Anyway, I've told my wife that my birthday present needs to be a 6 hour window when I am allowed to go back to Centrepoint and spend a few hours looking at old sleds and learning all I can.

Just over a hour from home. . . I'm a happy man!

[fastl82vette]

Hopefully they allow flash photography...

[cosmo440]

I know of this place. When I started my rebuild of my 80 liqufire, I was having problems with the heads sealing and I wanted to get it tuned. Since Larry was a JD guy, who better to work on it? Long story short, I live in Cochrane, a good 3hr drive there, my sled was in and out of his shop over a 2+ month period, in the end I spent $1300 in his repair work(not including fuel), my heads still leaked and it was in no better running condition then when I first brought it to him. I rebuilt the motor, again, and got 2 years of perfect running deere. I will never take anything to him again and not recommend him to others. I almost went to court trying to sue to get some of my money back. I have all my paperwork, a letter from an attorney and his response, pictures of his repair work. If you are thinking of getting work done there, don't. I found out the hard way that if you want something done right, do it yourself.

[SIIaCanuck]

Interesting experience. I do all my own wrenching work, I am more interested in having a parts supply and a place to go look at a sled collection my wife would never let me have.

Worth knowing about the down sides though.

[That Girl Racing]

There is no right and wrong compression gauge reading. (except for 0)They are a comparative value. Very rarely will you see a manufacturer give out a specific number. On any given motors you could get from 120PSI to 180 depending on the gauge. It is the differential that is important. The only true measure of cylinder wear is a leakdown tester. This dealership is baffling you with B.S.

[snowkat79]

There is no right and wrong compression gauge reading. (except for 0)They are a comparative value. Very rarely will you see a manufacturer give out a specific number. On any given motors you could get from 120PSI to 180 depending on the gauge. It is the differential that is important. The only true measure of cylinder wear is a leakdown tester. This dealership is baffling you with B.S.

+1 on that!

[JDT]

I have a stub guage(no hose) and a longer hosed one and they always read the same.

If they did not I would buy a new gauge.

Hose length is overrated anyway.

[TASKY]

If I have this figured out right, wouldn't a longer hose would just necessitate pulling the motor over more to fill the additional volume of the longer hose.

[SIIaCanuck]

Tasky,

I reckon that it only makes a difference if your release valve is at the gauge and not at the end of the hose. If it's at the end of the hose you'd be right, all you need to do is 'pump it up'.

I think this issue may be overblown but if the hose is too large an ID, then the reading will be low on the smaller displacement engines.

[That Girl Racing]

It is good to know that the 440 liquid Kawasaki engine can actually defy the laws of physics!!!!

[JDT]

There are pills and pumps with all kinds of redickulous claims.

(spelling error intended)

[lwb140]

There are pills and pumps with all kinds of redickulous claims.

(spelling error intended)

...todd