1996 Kawasaki STS 700 starting issue - PWC Forum: The best hang-out for Personal WaterCraft enthusiasts

djcboi1 · 07-02-2012, 05:20 PM

I have a 1996 Kawasaki STS 750 that if it sits for a day or so I have to pull a plug and put fuel (premix gas) in the cylinder and then it starts and runs great. Lately, I occasionally have to do this after only having it shut off for 20 or 30 minutes. Sounds like a carb issue to me. Any thoughts?

Thanks

SXI750 · 07-02-2012, 05:28 PM

I have the same problem with my 96 STS but instead of pulling a plug to pour in gas I just spray some starting fluid into the carb, it works just as well and is a lot easier. I believe the carbs do need to be rebuilt, but I haven't done it yet.

djcboi1 · 07-02-2012, 05:53 PM

Maybe yours is a little different than mine but there are several bolts that hold the carb cover on. IF anyone thinks that rebuilding the carbs would solve the problem I would definitely do it.

Thanks again

SXI750 · 07-02-2012, 06:14 PM

The carb cover is the same on mine. I just spray the starting fluid into the holes in the side of the carb cover and it works just fine

djcboi1 · 07-02-2012, 08:13 PM

I noticed the holes after I replied. I'll try that next time it happens. Has anyone told you that rebuilding the carbs would fix the problem?

ggauvin · 07-03-2012, 09:01 AM

Sounds like something is not quite up to par. Carb rebuild (or at least cleanout the filter screens and jets) is always a good idea if it hasn't been done in a long time. But other things to check.... does the choke fully close? Is there any leak in the fuel lines that let the lines drain empty while unused? i assume the tank and main line filters are OK or it wouldn't run OK after it did start. Some people don't like starter fluid 'cause it does not contain lubricant so the first firings are "dry". You can use WD-40 as a starter fluid... it is highly flamable and contains lubricant. Add a primer kit (available from many sources... squirts pre-mix directly into the carbs via easy to use plunger or bulb). On my personal skis, I make sure the gas switch is turned "ON" for 5 minutes before I actually try to start, to be sure the gravity feed has time to fill the carbs before cranking. They start a little slow if sitting for days or weeks, but fire right up after first start of the day. I don't use any other aid but the choke.

djcboi1 · 07-03-2012, 05:14 PM

Thanks ggauvin. I will check all the things you mentioned. I wonder if it has a primer kit already installed. There is a black knob located just in front if the exhaust manifold/riser. It only has about a quarter inch of travel but by working/pumping it I have had some success. Thanks again for the reply.

ggauvin · 07-04-2012, 01:37 PM

Whoa!! Don't pull that knob.
That is a drain. It opens a small vent in the lower crankcase. Purpose is to drain water that may have entered the engine during a capsize or other misfortune. Some people call it the Kawi self-destruct knob. When the seal gets old and brittle, it won't re-seal tight and air leaks into the crankcase when running... result is lean condition and overheat/melt piston, etc. Most owners block off that vent drain and remove the knob.
While it's only a remote possibility, a leaking drain might make it hard to start. (lean condition). The drain is hard to see / access... most owners pull the engine to work on it. that's a lot of bother. Take a compression check first (easy to do) to see if the drain or other weakness makes it hard to start.

98yota · 07-04-2012, 01:44 PM

Have you checked compression? Low compression will cause hard starting.

djcboi1 · 07-05-2012, 10:31 PM

Thanks all for the replies. I checked compression today and had just under 150lb on each cylinder, so I think I can eliminate that as a cause. Still need to check the choke and fuel lines. Thanks ggauvin on the info about the drain knob. Will definitely leave that alone.