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DIS SOB Deserves it's own Thread

etemplet

Moderator
Moderator
Fuel lines and hoses.... important stuff.

Just finishing up doing an engine install on 1996 GSX. Testing the fuel system I couldn't get a vacuum with my hand pump so I did some checks, replaced the fuel selector, tested the water separator, ended up installing a rebuilt baffle due to crushed fittings and lots of damage at the bottom. I put all the hoses on and fired up the carbs I just rebuilt. I noticed these carbs did pretty much the same thing as the new set that wasn't working but... I was able to tune them. Ski was hard to start initially but... it had to pull the fuel from the tank... it still took too long.

I'm sitting here thinking about why I'm having all this trouble getting fuel to the carbs... I checked everything. Then I remembered the first time I grabbed the fuel hoses, I noticed the were noticeably softer than the fuel hoses I use. BING !!! When I restore a ski, I replace everything in the fuel system and I use the thick black fuel line. These lines on the ski were new so I didn't replace them. BING!! The ski had one of those outboard hand pumps on the fuel line to the carb, I laughed the threw it in the trash. Third BING !! When testing the fuel system I tried to pull a vacuum (with my Mitey Vac hand pump) on the fuel system testing for leaks and couldn't get anything on the gauge. BING !! again. Hand pump, pulse. REVELATION : The lines are too soft and when the pump pulses, the lines collapse ever so slightly and diminish the pump's capacity. I couldn't get vacuum for the same reason the fuel pump is having problems getting fuel to the carbs on initial start up. The lines need to be ridged enough so they don't collapse under vacuum.

Give this some thought when your ski has issues. When you have a pulse type pump you cannot have any flex in the feed lines because it will diminish the pulse and thus the pumping capacity. I was sitting here wondering about this problem. After starting the ski the pump worked fine only because its capacity at RPM was enough to overcome the flexing. I'm wondering if this isn't an issue with us getting away from the gray fuel lines Seadoo uses. Hmmmmm.....

On a side note, this is why I don't generally work on skis for individuals... too much BS to deal with. This ski surely was an adventure. I'll be replacing the fuel feed lines tomorrow. No need to replace the return line as it is the pressure side. Touchdown's everyone.
 
I replaced all the feed hoses today. Ski started pretty quick with no fuel in any of the lines. Owner came to pick it up and I put the key in and I hardly touched the start button an it was running. No choke at all. Yesterday it would have taken 4 tries with choke and quick hands to transition to throttle. YAY !!!
 
Gene you are the man, BING!

Could you have seen all the responses I would have gotten if I had asked for help troubleshooting the carb problem? They would not have been wrong but I checked all that already. :D Though I never personally caused a problem with the hoses being too soft, I'm gonna make sure all mine a rigid. I wonder how many of us fight through the first start up of the day or weekend and the hoses are the cause to some degree. Oh well.... On to the Speedster, then the GTX, Then the GTI.... (oh this one is gonna be fun)
 
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