So I'm at a loss... I bought this machine not running and have struggled so far to get it running right. It's a 94 xp 657x I replaced the mpem and all the fuel lines and deleted the shut off/reserve and replaced the filter with a inline type and rebuild the carbs but did not change the jets or springs from the carb sticky I've set it at 1/4 high and 11/4 low. It starts up pretty good and idles well just won't get past a 8th or 1/4 throttle with out bogging and dieing. Plugs read really rich I've tried fine adjustments and large every way possible with no success. What am I missing could the bog be from anything else? Any input appreciated as I'm at my witts end. I'd really like to injoy this ski at least one time this season... thats pretty much over as I'm in Ontario canada
657x wont rev up
- Thread starter Daphatdub
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Fresh plugs haven't checked compression tho...spark seems ok. It fires right up when I have it set at recommended high and low carb adjustment settings and starts to rev decent I'd say just off idle to like a 8th throttle than boggs hard and dies or almost dies. Plugs show in my opinion very rich but I cant get it leaned out
That's the thing ... I wouldn't know what a lean bog sounds like ... I assumed rich because of the black maybe wet plugs. I just checked compression 160/165 is that even right ? It's seemingly a stock motor. I used the same gage yesterday on my 1200 slx and got 135 across all 3 cylinders. How would I check if my spark is good enough or timing is enough? That's just guessing ... it idles nice, starts decent. Revs or starts to rev up seemingly well just off idle but anything more than a little throttle it just bogs and dies or almost dies. The big jet says 2 with the stamp shape so I'm assuming original mikuni I can't read the small one and the springs were yellow. I've been thru the stickys and I think everything is correct but not sure about the spring pop off or jet. I didn't change them I just did the gaskets and diaphragm. Should I make or get a pip off gage ? Could this be carb issues or more likely timing or spark.
Hmm would my plugs still read really dark ? I'm going to pull the carbs right now and try to identify the pilot size. I removed the selector and the factory fuel filter. I have a inexpensive inline filter in right now, could it not be flowing enough? How would I test that? I'll remove it as well and see if it makes a difference for now... BTW thankyou so much ! The information and input of others on this forum has allways been invaluable
Ok awesome I'll pull it out and try again. I'm allready chasing my tail in circles! I pulled the carbs again to look for number on the jets the pilot says 7.5 I can't see anything on the main and the needle seat says 2. They have the square mikuni stamp. The spring is silver or yellow could be stains and the arm is dead flush with the surface on the carb body. Compression was 160 if i can trust my gauge. Could my flywheel be on wrong? Could it start well and idle well if it was wrong or installed way off. ? Out of the water it revs up with the load on the pump it just bogs
I've shot carb cleaner in the carb and made sure it comes out the tiny holes just like described in your stickys . I'm satisfied the carbs are clean. Thankyou for chiming in on this your carb rebuild thread should be the Bible on this stuff. It's proven priceless so far for me.
I'm with mikidymac....compression on two strokes are key. You can get good readings if you crank long enough, but it needs to be quick to get there. Easy enough to pull the heads off and look at cylinder scoring too. This engine being 25 years old and if it's never been touched probably needs attention.....I'm going g through a similar one right now with a 95 SPX
Needle and seat were a 2. main jet was a 132.5 and the pilot was 67.5. I checked some other carbs I had around and the seats were 1.2 and 1.5 the pilots were 67.5 and mains 130. Also the other needle had tiny holes on the body's but my originals did not. I don't know if it's added for the smaller size or maybe they were after market. I've switched mine ( needle seat main and pilots) for ones from the other carbs and will hopefully try it out today.
I'll have to pick up some different mains and pilots tomorrow. From the 3 sets of carbs I had kicking around they were all different yet none what factory spec from seadoosource chart says they should be. I went with 1.5 130 67.5 and checked pop off today it was around 35-38 every time and they both held pressure. What should compression be ? Mine is 160-165ish if someone has cut the head or done other work to this motor what spare jets should I pick up to have on hand to get this thing snappy.
Madpaddler
Member
I can tell you from bitter experience that a 2.0 needle and seat is way too much. I tried that route with mine. I know the N/S needs to be a 1.5 you likely had low popoff and were flooding due to that and the bigger N/S.
AKnarrowback
Well-Known Member
The 2 on the needle/seat stood out as a red flag. This makes me think someone has goneb in and mixed things up at some point in the past.
You need to stop chasing your tail. Take a step back and start confirming the carb is calibrated to factory specs on the low speed jets, you screw settings are correct, high speed jets, needle and seat are the correct size with the correct pop off.
Also, find a better compression gauge. A stock 657 should be showing 150 psi at best. Anything over indicates a moded motor or malfunctioning gauge.
You need to stop chasing your tail. Take a step back and start confirming the carb is calibrated to factory specs on the low speed jets, you screw settings are correct, high speed jets, needle and seat are the correct size with the correct pop off.
Also, find a better compression gauge. A stock 657 should be showing 150 psi at best. Anything over indicates a moded motor or malfunctioning gauge.
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