98 SPX rough starting, once warm runs Great!

[Madskidog]

My ski has run great all summer...until the last couple of weeks. Recently, it has been very difficult to start to the point of draining the battery trying (this is only the second year on this battery). As its trying to start, it fires a few times but doesn't really catch. With the right combo of choke, then half choke, then no choke and full throttle, usually it does start (if you hit the right combo before you kill the battery).

Once started, it runs a bit rough for 5 to 10 min until suddenly it runs great for the next few hours until it sits and cools down for a few hours. Then, same chain of events. Do you have any ideas? Plugs don't make sense, battery doesn't fit the puzzle, bad gas doesn't sound logical, so I turn to the forum for help.

Thanks for your insights!

 

[Dr Honda]

check the compression. it may be getting low.


If it's ok... then it's time for a carb rebuild.

 

[Madskidog]

Tony

Thanks for the suggestions. I had not thought of compression as a possibility, but carb definitely did. For compression test, since my issue is with cold engine, where do I get the normal compression range for this engine cold?

 

[Dr Honda]

You always do a compression check cold. A warm engine will seal better, and hide problems that are just starting to come out. A cold seadoo engine will show 150 psi if it's in perfect condition. Anything over 135 psi will run well. If it's below that... it's time to freshen up the top end.

 

[Madskidog]

Perfect! Thanks Tony!