Flat Slides

[xlink]

I have flat slide carburetors on my bike (1992 water-cooled gsxr600). I had the tank fuel valve fail on me in July and replaced it with a Pingle (on/off) valve. THe bike ran great on 8/30 at BHF until the 6th section when it started leaking fuel from the air vent (marked as 81 on the diagram). Needless to say, I was pretty upset and missed the last two sessions. I dont know if the tank valve had anything to do with it or some crap got in and is making the float stick or the floats are punctured. the strange thing is that the right air vent leaked at the track (between 3 & 4) and when I turned on the fuel at home the left one leaked (between 1 & 2). I know that a lot of you have moved to fuel injection and I don't blame you, but I thought I'd check before I take it apart...below is a diagram of the carburetor (I'm not sure if it is the exact same model but it resembles it pretty good)

The bike was jetted and dyno-tuned by Matt (MD racing) in June and it pulled strong and smooth 95 hp's @ the wheel.

http://www.sudco.com/fcrdown_diagram.html

 

[physicistkev]

I have a set of Mikuni flat slides on my old gal. You got bit by something that happens to all flat slides when you go to a non-diaphragm activated fuel petcock.

When you turn the pingle on, it's on. It is actively allowing fuel to run down the fuel line to the carbs. If the carbs have any age on them at all the fuel will leak down passed the float valve filling the bowl and eventually overflowing out of the float bowl vent.

You need to replace the float bowl valve and seat, which should be parts 36 and 42. This will give you a tight seal on the incoming fuel line. My very strong suggestion is to trash that pingle fuel valve and replace with the stock Suzuki one. Even if you replace the float valve assembly I guarantee you will have fuel starvation issues with the pingle valve eventually. They don't have enough of a neck on the in tank filter and any thing that gets into your tank will eventually clog the screen, or the screen will come off (more common) and all it takes is a pinch of anything and you can no longer get enough fuel from the tank.

The pingle's always give to much fuel or not enough. Buy the stock replacement
http://www.bikebandit.com/suzuki-motorcycle-gsxr600wn-1992/o/m6216
$115.43 at bikebandit.com

Money well spent, trust me.

Kevin

 

[Motofun352]

Pingle

While not quite the same thing, I replaced my diaphragm fuel valve on my '82 CBX with a pingle valve....Works great after 4 years, HOWEVER, always remember to shut the valve off when not running the bike. This makes a cheap like security device as well as none of the young crooks ever heard of anything as antique as shutting off the fuel valve.

 

[xlink]

Kevin, the the screen sock of the pingle valve is pretty tall - 2.5". Somebody at the WERA board said that an in-line filter is a good idea...Do you think that replacing the fuel valve with stock will solve the problem by it self? If not, I'll need four bowl valves, four seats and four bowl gaskets, right?

Motofun - most stolen bikes are loaded onto trucks - we almost lost our 900RR. My brother went to the parked bike and saw a U-haul truck with open doors backed up to the bike and two guys getting ready to load it...that was the last time we left it unattended.

 

[physicistkev]

The stock screen is about 5 inches tall, the reserve screen is about 2.5 inches. The biggest issue I have seen is the screen coming off of the pingles.

Going to the stock petcock will not solve your leaking problem. Well, it will make it so that the bike could only possibly leak when the engine is running and pulling on the diaphragm. Since the diaphragm is only pulled when air is drawn into the cylinder that the vacuum tube is hooked up to the chance of an overflow goes way down, but it will not go away completely.

Let me put it this way. I had a leak when I went to a Pingle. I went back to stock and the leak went away. After a while longer it started to leak with the stock petcock. Since the fuel flow is only on 25% of the time when the engine is running you get less fuel flow than a wide open pipe.

When in doubt, use the stock parts. They are typically better.

Kevin

 

[xlink]

Thanks Kevin. Let me just tell you that when I had the stock valve it was on "prime" at all times. Isn't that the position that bypasses the diaphragm?

 

[physicistkev]

Yes it is. Prime, would be the same as the pingle in the on position. Should only be used if the float bowls are empty. ie The bike has been sitting for a month. And, you should only set it to prime until the float bowls are full, about 45 seconds.