Sad SRX 700 with low compression!

T

trublue

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Nov 25, 2013
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7
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Wainfleet, ON
Looking for some help here with the SRX that has been out a few times this year with no issues. Last time out my son was riding it and he came back with it barely running but seemed to idle ok. Initially thought it was a coil or spark issue but ruled out both of those and decided to check compression to rule that out and found it to be 70 psi across the board. Then did a wet test thinking that it may be a ring issue but numbers stayed the same. Any ideas as to what else should be checked or what else could cause low comp across the board?
 

I would try another compression tester. I would also clean the carbs. Especially under the float valve seat. There is a screen under it that could get clogged. Check the in tank fuel filter. They can come off and suck a bunch of junk in the carbs. Also check the pulse line that goes from the fuel pump to the block and make sure it doesn't have fuel in it.
 
Cleaned power valves year before last but last 2 winters sucked here so I didn't get to ride much.
 
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I think my tester is good because we use it in my auto repair shop and seem to work fine. I did clean the carbs but will check the screen (which I skipped over) and check pulse line also.
 
You could also try propping the back of the sled up and see how it runs. Its hard to try to diagnose something without having it in front of you but I have seen clutch problems do some weird things too. I had a vmax that the clutch messed up on and I thought I blew it up. I ended up figuring out it was the primary needed rebuilt. Just another thing to check.
 
If tors is bypassed I would start in the carbs and check the fuel filter just to try to get stuff ruled out and go from there. Was it running good and then instantly started running bad or was it more gradual?
 
It was running great for several rides and then suddenly started this at the end of the last ride. I'm going to check compression with another tester from one of my other techs in my shop to ensure that my reading are on.
 
it could be the throttle switch, even tho you bypassed the carb switch for the tors, the throttle switch can not be bypassed, its the one in the pivot of the throttle, you can check to see if its working by pinching the pivot and move the lever, it should stutter.
 
if that tester is a automotive one it may not read correct as it is designed for larger displacement engines. a 700 is only 0.7 L, each cyl only 0.233 L. the small cylinder simply do not displace enough air to make the larger gauge register correctly. seeing that they are all the same, i would think they are okay and not your problem.
 
mrviper700 said:
it could be the throttle switch, even tho you bypassed the carb switch for the tors, the throttle switch can not be bypassed, its the one in the pivot of the throttle, you can check to see if its working by pinching the pivot and move the lever, it should stutter.
Click to expand...

I was wondering about that but I wasn't sure exactly how that worked. I bet that is what it is.
 
Ok so I tried my other tech's tester and bam 125 across the board so I told him I liked his tester much better, LOL! So glad I have compression but still not closer to figuring this out. Just went to the shop and fired it up again to check the throttle switch as mrviper700 suggested. Idle is fine and holding the pivot while applying throttle made no difference. What does that mean?
 
I just tried testing my switch with an ohmmeter and when I used the black wire with white stripe and the black wire with yellow stripe it would show continuity when I depressed the switch. Most likely this is the problem. Also you might already know this but don't hold the prongs with your fingers or it will show continuity. They are long on my tester and I was holding them with my fingers in the plug for the switch. Lol. I never knew that. By the way I would like his tester better too. Lol
 
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