05-11-2014, 10:50 PM #1
94 xp 657x just doesn't sound right...
I picked up a 94 xp for free a couple months back and it had the nossle taken apart when I got it. So this weekend I was able to almost put it all back together but I wanted to test it first and flush all of the crude that was built up in it. I think it may have some "issues". Too good to be true right? ... a free xp?! I have uploaded a video of it running. Listen carefully...
What I got out of this:
1. It sounds terrible... it sounds like something is loose in the engine. I inspected the pistons and they both have 120 psi compression. They move freely with no issues. Very little cylinder wall damage. I have a brand new extra top end too.. if it is needed. Could it be a rod bearing? or anything in the crank case? I took the PTO cuppler cover off to see if the drive shaft was warped. But I can't tell anything.
2. It smokes profusely when it runs; more than it should. It is pre mixed with the oil injection block off kit and mixed 50:1. Could it be leaking from the other two oil lines that lube the rotary gears in the crank case? I have a GTX 657x and it smokes 1/10 of what this xp does!
3. Throttling it, kills it. It can only idle. Giving it anything kills it. I'm sure this carb needs nursed back to health.
4. It vibrates terribly.
Let me know what you guys think. I would like to have some lead to where I need to investigate.
Last edited by nsschwenk; 05-14-2014 at 08:48 AM.
05-12-2014, 10:55 AM #2
Well for starters the idle is too low. Which could also be why it's shaking so bad. Check for broken motor mounts or a loose bedplate. And if giving it throttle kills it then you have a thorough fuel system cleaning ahead of you.
05-13-2014, 03:31 PM #3
05-13-2014, 04:33 PM #4
The fuse missing and wires cut are on the trim control module. It's probably internally shorted and thus why it's disconnected. The other large module is the MPEM and the smaller box I believe is a rev limiter.
Pull carbs and check out the needle and seat. If the needle tip is broken off the carbs will flood profusely.
05-13-2014, 09:17 PM #5
To me it sounds like the timing is off. Try revving the ski up and send us another video.
05-14-2014, 08:45 AM #6
Myself: Thank you for your feedback. I will upload some pics of my carb inspection and clean.
Blairwill4: I tryed reving up the engine but it doesn't do anything at all. It only really slowly kills it..
05-14-2014, 08:59 AM #7
I did a more complete clean of the carbs last night. My needle and seat are okay and everything is spotless, clean, and clear. I did notice that my High Speed screws were completely closed or barley open.
I did notice in this picture that the right carb was completely dry and dusty on the inside like no fuel has passed through it in a while.
More pics of the carbs.
What are the correct initial high/low speed screw settings? The service manual is really unclear on the initial settings.
LS = 1.5 turns from seated
HS = 0.25 turns from seated
05-14-2014, 09:15 AM #8
I took some pictures of the cylinders and pistons. They do have some large scratches on the walls near the ring gaps. It explains the low compression. They still are combusting fuel correctly as they are not dark and wet. My objective is to simply just get the engine running correctly and replace the top end in a few months at the moment.
I notice the pistons have a large ring gap.
The manual says it should be (0.25-0.4mm) to a max 1mm clearance.
I am going to remove the cylinders tonight to inspect the crank case. I am looking for piston rod slop and where my oil leak is at.
Myself: I can't get the ski to stop smoking really bad. Could it be from a leaking rotary valve seal?
05-14-2014, 10:32 AM #9
check pop off on the carbs, I have taken carbs off befor that was missing diaphrams and gaskets, be sure your not missing anything on carbs. is will sound better when the idel is turned up.
05-14-2014, 11:02 AM #10
Derek45: Thanks for your input!
- I double checked and I'm not missing anything on the carbs. I don't have a tool to check the pop off pressure. Is there a way to check it with out the tool? Can I make a home made leak down tester that will work for the application? I adjusted the needle and seat to where they need to be with very little slop.
- I can't get the idle to increase on no matter what adjustments I make on the carbs.
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