01-15-2012, 09:54 PM #1
- Join Date
- Jan 2012
1994 750 SS hard start after sitting
I'm trying to get my sister's ski back to where it starts like it should after it's been sitting. The problem is, after sitting for a while (not sure if it's just a day, but definitely about a week or longer), it's extremely hard to start. The problem is fuel isn't getting to the carbs, either it's evaporating or getting pulled back into the tank. With the choke on there's not enough vacuum to quickly pull fuel from the tank, so I've found the easiest/quickest way to get it running is to pull off the intake hose at the flame box and cover the opening with my hand, then turn it over. All that vacuum is able to pull fuel to the carbs pretty quick and then once it's running it has no problem starting and running all day.
There are two issues I've found and possibly something else that's contributing to the problem.
- The fuel tank check valve is faulty, it's unable to hold pressure in the tank
- The fuel level sending unit's rubber cap is pretty cracked up, but I haven't been able to see if the cracks go all the way through. There are no gas fumes in the hull like there's a leak, but it is something that should be fixed
Would the faulty check valve cause this hard start? I wouldn't think so, but it certainly doesn't help. At least with a properly sealed tank and fuel system there's a chance it will have enough pressure to prevent the fuel lines from draining back into the tank...
...which brings me to something that may be contributing to this problem, which is the trailer it's on tends to be stored more nose down than level or nose up. This means that with no pressure in the tank the fuel has the ability to slowly drain downhill back into the fuel tank. Check valve and sending unit issues aside, I think I'm going to do an experiment over the next week. Start it up and then prop the trailer so that it's more nose up, then next weekend I'll see how hard it is to start.
All these things could all be working against me here whereas one problem by itself wouldn't really cause a problem. Yes, no, maybe? New to skis but not exactly new to motorized vehicles, so just trying to look at how the fuel system is set up and why this could be happening.
Thanks for any suggestions!
01-16-2012, 10:34 AM #2
yes, you NEED to replace the fuel check valve.
it sounds like it is an older ski, that has probably never had anything done to it ( tune up wise).
go through the fuel system completely. rebuild the carb ( use ONLY genuine kehin brand parts.) replace fuel lines, fuel select valve, the dried out tank sender cap, or assy, replace the fuel filter, etc.
put in new spark plugs, take the plug boots off of the wires, and cut the wires back a 1/4 inch or so, then re-install the boots.
properly tuned, the 750 motor starts VERY easy. a lot of times, even without the choke.
i have most any part you would need, here in stock if you want. feel free to email, or call during hours listed if i can help.
01-16-2012, 11:03 AM #3
- Join Date
- Jan 2012
Thanks, I took a look at your used parts and definitely like the price of the fuel sending unit compared to an OEM part ordered from my local dealer. I'll let my sister know and see what she wants to do. It's got new plugs, but that's about it. She really hasn't done much regular maint on it so I'm sure it could use a carb rebuild and such.
01-16-2012, 11:30 AM #4
I own a '92 SS and have had this issue also. The problem on mine was the return and fuel pick-up were constricted at the tank. If you pull the pick-up off the tank it is made of plastic and has that chrome type coating. This degrades severely over the years and will plug up the lines. I emptied my fuel tank (syphoned) and made sure it was clean. I cleaned up the pick-up tubing holder, screens, etc. and put it all back together.
Mine is still occasionally difficult to start cold and I plan to install a primer. I have adjusted the choke to where it is closing all the way. It is a good idea to make sure the fuel lines are clean and new fuel filter. Old gas will get you too.
I cleaned my carb and did not use kit. It has worked fine since this issue. A fun little ski for sure.
The above gentleman is John Zigler. He is a great resourse for any of your needs with parts, advice, etc. If you send him $$, he sends you what you asked for, quickly. He runs his business like he cares about customer service, something unusual these days. So do not hesitate to use his services.
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