96 SPX Issues

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I am a long time boater with above average mechanical skills. I don't know a whole lot about PWC's. I have the opportunity to get a 97 SPX at a steal of a price ($850). The ski itself is in good shape, pump is good, no issues on the ouside. The motor is corroded on the outside(paint missing, white chalky spots, etc). It is said to have sat for 5 years (ran fine prior) and the current owner has tried to get it to run right, but is giving up. He has replaced the fuel and oil, oil pump, and rebuilt the carbs. It does run, however not right. It needs a shot of fuel down the carbs to cold start, which it then does immediately. It idles really fast and does not run slow very well. On the water, once it gets on plane and WOT, it runs great. Compression is 143 and 138 cold throttle closed. It also is leaking exhaust around the plugs on the exhaust pipe. The owner seemed pretty up to speed on PWC's. He was able to try a diffeerent ECM on it, and that did not help. He says he performed a pop test on the carbs and that he is sure the carbs are right and clean. He also checked the rotary valve and said it is in time. He thinks the timing advance is 'stuck' on high due to the stator. Here are my questions...<br /><br />1. I don't think the stator is an issue, since it is getting spark. What do you all think?<br /><br />2. Is the compression (138/143) in line for a 717?<br /><br />3. I still think the carbs are not right and it is running way too lean at low RPM, thus the high idle, no cold start, and acceleration problems. When you listen to it, it sounds lean to me.<br /><br />4. Anything internal or ignition related that would cause these symptoms?<br /><br />5. The corrosion bothers me. I have not sean any that have the paint flaking off the head and pipe the way this one is. He says it came from Arizona and does not think it was in salt water.<br /><br />I am fine with getting a pipe and waterbox off of ebay to fix the exhaust leak. Just wondering how big a gamble I would be making thinking carburation is the issue. For the price, I am even ok with getting a new shortblock down the road a little.<br /><br />What are your thoughts?

 

[Jeff Walkowiak]

Re: 96 SPX Issues

first the exhaust bothers me as the welded plugs are notorious for leaking but water should be coming out not exhaust the pipe is closed and a water jacket is around the inner pipe, so if exhaust is coming out of the leaking plugs something is amiss. as for the carbs I would definitely pull them apart and go through them again and closely check the front carb fuel pump assembly to be sure it is correct and in good condition, also the pulse tube could be loose and this will hinder the pump plus cause a high idle from a vacume leak, further I would go directly to the reserve pick up off the fuel tank and bypass the fuel selector switch, those are a constant problem with fuel delivery, sea doo fuel lines are another big problem and I eliminate them , I replace them with clear vinyl tubing and use good clamps NO cable ties, any leak in the suction side will pull in air and cause a lot of problems, the internal filters in the carbs are another concern as they do clogg up pretty bad and starve the carbs for fuel, the diaphrams are another problem , if they are not new and factory type you can experience trouble with those, look for the red dot on the center of those if it is silver it isn't a mikuni diaphraghm, you can buy yamaha part numbers seperately for about half of what the sea doo part is and they are the same diaphrams from mikuni. also be sure the carbs are synchronised that is important! the top jet screws should be all the way in the bottom screws should start at 1.5 turns out.