97 GTS has spark but wont start/run

[jrfleming]

Just cleaned and rebuilt carb, fresh fuel, new spark plugs, and new battery but it wont start. It was starting with a little help (2 tblsp gas in carb) and actually ran long enough for me to switch on the water hose just before it cut out.

Fuel is now flowing, sparks and cranks over just fine but not starting---even with adding gas to cylinders.

Any suggestions?

 

[Coastiejoe]

If you have fuel spark and compression it will run, assuming the timing is correct.

Do a compression test with throttle wide open and post the results.

 

[LouDoo]

I agree with Joe, I would also suspect the rotary valve timing, but check the compression so we can get a general idea of the condition of the engine.

Lou

 

[Coastiejoe]

Sorry, double post.

Not sure how it happens several hours later.

Maybe I was sleep walking....

 

[jrfleming]

Okay just got home from work and tested compression as follows:
front cylinder: 120 psi
back cylinder: 180 psi

I am going to retest as this seems like an odd pairing of pressures.

Retested at 120 and 120--must have had fuel in the gauge on the first test.

Please tell me more about the rotary valve timing and any other suggestions.

 

[Coastiejoe]

That is a large spread.

Just to confirm, no plugs, wires grounded, throttle wide open,,,

 

[AdamXP800]

Yes, I would retest. One cylinder way hight and one too low. Either the calibration is off, bad tester, or there is problems here.

 

[smc0922]

Sounds like a stuck RV with those numbers. Pull the carb or the whole RV assembly and verify it spins with the motor. CAUTION- the RV may stick to the cover and come off with it, so beware. If it falls off the splines of the shaft it will need to be re-timed.

 

[jrfleming]

Pulled the carb off and about to remove the RV cover. Does the oil injector need to be removed or will it come off as a unit with the intake manifold? Diagrams on this level seem to be a little lacking.

 

[smc0922]

It can come off as one, but stop here. Look down the hole and off to the front and off to the back, you should see the intake ports. Spin the engine by hand, can you see the RV rotating and opening one port and then the other?

 

[jrfleming]

Finally got the intake and oil pump off. RV looked good so of course I had to pull it off. Rotating the engine with everything exposed got to the root of the problem--it was totally flooded--mainly fuel but also some water from the hose connection (it stalled out just after i had turned the water on when this all started). Anyway I reset the RV timing and put her all back together again. She started up on the first crank--what a relief. My battery is now too low to start her again so will charge and leave her be for a day or two. I figure I will need to play with the low speed (lean mix) and high speed (rich mix) since I rebuilt the carb. I gather these are pretty sensitive.

Thanks for your suggestions. I'll post again once I have had a real shot at running her.

 

[smc0922]

I'd say you need to inspect the needle and seat very closely, if it flooded then I would say check the pop-off pressure as well. Changing the mixture won't really help a flooding issue if the carb is leaking fuel into the engine. If it is just running rich then yes, set the mixtures to spec and see what happens then.

 

[Strizzo]

Wow, I had to google el lago to see where it was, we aren't too far away in west houston. I would bet that your center seal leaked oil into the case over the winter, I'd be surprised if it was full of fuel. Surprised though that you weren't hydro locking while trying to start. Do you ride on Taylor lake or clear lake? I haven't ridden down there yet, we usually go to lake houston or camp at lake Travis in Austin.

 

[jrfleming]

I mostly ride in Taylor Lake (it is walking distance from the house) but get into Clear Lake and even the Bay occasionally when conditions are just right. It can get pretty choppy on Clear Lake but the north end of Taylor can still be like glass. Good network of water to play on down here, the public ramps are accessible with park areas nearby but not beach (unfortunately).

When I returned to check the ski again it started right up and then stalled and would not restart. It is indeed flooding, fuel leaking into the cylinders. Not sure how to remedy the carb at this point, might just get a replacement carb. I'll check the forum for fixes and replacement carb.

7/2/2013-Replaced the carb with a used one ($69) on Ebay this past weekend. That did the trick. It is now running better than ever. Hope to play on the water on July 4th! Thanks for all the thoughtful posts--I'll test the old carb and see if I can restore it for later use as a spare.