SRX 700 low compression

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destey

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Jan 28, 2010
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Vermont
Got a '99 SRX 700 with somewhere around 12000 miles (speedo stopped at 9something), no motor work done (original pistons, rings etc). Feels like it runs ok. I picked up a compression tester and got around 100psi for all 3 cylinders. I remember checking it years ago and it was around 125 Any chance I don't need new pistons? I was going to take the cylinders off tomorrow to get a better look and upload some pics of the pistons, anything important I should know? I've never gone into this motor. What will I need to put it back together, base gasket and new head gaskets (or do they use orings)? TIA
 

A leak down test is probably the easiest way to find out the condition of your engine without taking it all apart. I baught a leak down tester on Amazon for 100$ cause I was wondering the same thing about my 700 redhead with 9300 miles.
 

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You will need a base gasket, the 2 O-rings for the heads on each cylinder, and the gaskets from the water rail to the heads for the top end. You will not know if you need pistons until you get them out and measure them. If it were me and it is still running fine, and this late in the season, I would wait and go through the whole engine so you can change the crank seals and water pump housing gasket at the same time. But I am also obsessive compulsive when it comes to that kind of stuff.
 
drew24 said:
You will need a base gasket, the 2 O-rings for the heads on each cylinder, and the gaskets from the water rail to the heads for the top end. You will not know if you need pistons until you get them out and measure them. If it were me and it is still running fine, and this late in the season, I would wait and go through the whole engine so you can change the crank seals and water pump housing gasket at the same time. But I am also obsessive compulsive when it comes to that kind of stuff.
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I think you talked me into a complete rebuild. I'm unemployed at the moment with plenty of time, so this would be the time to do it. I've got a phazer to ride for the rest of the year, so I'm ok with it going down for the season.

How should I attempt this, pull the motor then start tearing it down?
 
destey said:
I think you talked me into a complete rebuild. I'm unemployed at the moment with plenty of time, so this would be the time to do it. I've got a phazer to ride for the rest of the year, so I'm ok with it going down for the season.

How should I attempt this, pull the motor then start tearing it down?
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X2 - with that kind of miles, I'd forgo a leakage test and go right to opening it up and start measuring/inspecting.
 
snomofo said:
X2 - with that kind of miles, I'd forgo a leakage test and go right to opening it up and start measuring/inspecting.
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What kind of measuring equipment do I need? I used to measure parts at my old QC job but now I only have a digital caliper.
 
Also I have another bottom end that I bought from a member here. Say the runout on the crank is ok, should I use the current crank until it dies or just put in the newer one? The bottom end I bought I filled with 2 stroke oil for storage. Not sure if that was a good idea or not?
 
I would guess the crank is probably fine. You could always send it to a good crank shop and have it welded and trued if you are concerned about it. The 99 cranks weren't welded. I sent mine off and had it done and it made me feel better about it knowing it was done. It all depends on how much you want to spend and if you plan on keeping the sled for a while. Also check the gear on the oil/water pump shaft for wear while you are in there.
 
I’ve read that there is a lot of variance between compression testers depending on the quality of tester itself. Also, whether testing a hot or cold engine. Both my 98s tests 112 across all 3 cylinders when hot. If I test then cold them they are at 121. What is they best/right way to test?
 
Clutch doesn't seem to want to come off. I've got the tool as tight as I dare go, its just started to mushroom. I did a search and tried the grease trick, though it seems difficult to get all the air out. Not really possible to put it on its side where I have the sled to do that water trick. I was thinking of heating the outside with a propane torch. I have oxy-acetylene but that clutch looks aluminum and seems like it would melt easy. Any other ideas?
 
destey said:
Clutch doesn't seem to want to come off. I've got the tool as tight as I dare go, its just started to mushroom. I did a search and tried the grease trick, though it seems difficult to get all the air out. Not really possible to put it on its side where I have the sled to do that water trick. I was thinking of heating the outside with a propane torch. I have oxy-acetylene but that clutch looks aluminum and seems like it would melt easy. Any other ideas?
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I'm is the same boat as you, tearing down my sled. I have it down to bottom end and need to pull clutch. I don't have puller so need to order one or borrow one. Once it's off let us know what you did as I would appreciate that. Most I've read on removal, as I have yet to do it says to use the grease on it or heat as well.
 
just lightly tap it, the vibes will do the trick. The bearings may be 150 but they are also steel, dont beat on it and they will be fine.
 
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