1993 Sea-Doo ?GTX? starting issue - Where do I start?

[Kingfisher23]

Hi all!

I recently acquired a 93 Sea-Doo (not sure exactly which model, it is purple and has an air-scoop on the lid of the storage bin up front), and I'm trying to get it operational. The previous owner says it ran fine last time it was in the water, but it has probably been sitting a year or more at this point.

I installed a new battery, new spark plugs, and I filled it with fresh gas. I also pulled the wires from both plug boots and trimmed an inch or so of old wire. When I hit the starter, the engine turns over fine but it will not fire up. Visually, the engine appears to be in good shape. The PO had the lower unit rebuilt a few years ago and hasn't used it much since.

Where should I start my trouble shooting? I'm pretty mechanically proficient (just finished rebuilding my jeep engine), but I don't have experience with jet skis at all.

Thanks!

 

[hotrodssnova]

Check that you have spark on the plugs. If so, squirt some pre mix in the cylinders, put plugs back in and try to start. If it starts, I would do a compression test. If they are within spec, clean the carbs, tank, fuel lines, filters.
Pretty much a standard procedure for a ski that has been sitting for a while.

 

[clmboating]

Seems to me like you've got yourself a GTX, anyways. Check out the compression, is it good or bad? This will start our trouble shooting process.

 

[Kingfisher23]

Thanks for the responses!

Looks like I have good spark from the plugs. Didn't get a chance today to spray fuel directly in the cylinders, but I'll give it a go tomorrow.

I put a compression tester on the cylinders, and with just the starter turning them over I get close to 150 in the rear cylinder but only 100 or so on the front. What are specs for the compression, and does an accurate reading necessitate having the cylinders actually run to normal operating temps?

In looking at the engine, I can see that the line from the fuel tank to the carb looks almost black. Is that a mix line or is it likely gummed up?

 

[Coastiejoe]

150 is perfect, 130 is fine, 120 you will be doing service over the winter. At 100 you are pretty much done. Plus, more than 10% between the cylinders is an issue and you are WAY over the spread.


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[benjilafouine]

Yep. Rebuild time. I had a 130 and 90 and naturally cylinder and piston was stripped on one side. Bye Bye engine.

One suggestion: if you can insert a digital camera in the bad cylinder, you should find some damage (not sure where you will find one however).

Benji.

 

[Kingfisher23]

When I saw the compression numbers, I was afraid that would be the response. Good thing I only have about $200 in the ski so far. I'll see about running my inspection scope into the front cylinder to look for damage.

What does a new engine for one of these run? And would it be worth the money to get it operational?