Kawasaki Motorcycle Forums banner

1 - 8 of 8 Posts

·
Registered
Joined
·
2 Posts
Discussion Starter #1
My 1977 KE175 has a part on which I can find no information at all, other than that it is called a fuel pump drain. When the fuel petcock is open, whether the engine is running or not, fuel runs straight out of this drain on the front of the engine, as if it were a direct line to the tank. I cannot find any information on any forum, catalog or shop manual about what this part is or why it's there.

My question is: What is this Fuel Pump Drain and why is it there? If fuel is constantly running out of it, how do I stop it?
 

·
Registered
Joined
·
653 Posts
If you're talking about the "fuel drain pump" mounted on the engine below the cylinder-- it's a small diaphragm pump that runs off crankcase suction and pressure to pump out any overflow gas in the chamber that holds the carb (instead of an overflow pipe)--- If it has a hole in it's diaphragm material, you end up with a vacuum leak into the crankcase (which could upset your fuel mixture) It's really a dumb-*** feature and used pumps are expensive! I suppose you may be lucky but it wouldn't hurt to carefully open it up and look for holes. I wondered about plugging the hole into the crankcase but ended up making my own replacement diaphragm from the rebuild kit from some mikuni carb off an atv. If you have fuel running straight thru, you likely have a float problem in your carb? I have the same bike.
 

·
Registered
Joined
·
733 Posts
If you're talking about the "fuel drain pump" mounted on the engine below the cylinder-- it's a small diaphragm pump that runs off crankcase suction and pressure to pump out any overflow gas in the chamber that holds the carb (instead of an overflow pipe)--- If it has a hole in it's diaphragm material, you end up with a vacuum leak into the crankcase (which could upset your fuel mixture) It's really a dumb-*** feature and used pumps are expensive! I suppose you may be lucky but it wouldn't hurt to carefully open it up and look for holes. I wondered about plugging the hole into the crankcase but ended up making my own replacement diaphragm from the rebuild kit from some mikuni carb off an atv. If you have fuel running straight thru, you likely have a float problem in your carb? I have the same bike.
Could not have said it better myself. Listen to the "cop"
 

·
Registered
Joined
·
733 Posts
Cool, sounds like it should be a fairly easy fix, then. Good thing there's so little to go wrong on these old 2-strokes.

If it is a carb float issue, can I replace the float & rebuild the carb or will one of these work?

Mikuni Universal Round Slide Carburetors - JCWhitney
None of those carbs will work. Rotary valve engines use uniquely designed carbs because of how they are eclosed behind a cover. If the float has a pinhole in it you can seal it up by dipping it multiple times in some fuel tank liner like RedKote or POR15. Rebuild kits for carbs generally only include some gaskets, o-rings, float needle valves and maybe new jets and needles. The rebuild kits will NOT include the slide or float.
 

·
Registered
Joined
·
653 Posts
Adding to what Junkman said--- you're carb could probably do with an overhaul anyway? The low speed jet on mine was so badly plugged, nothing would clear it ! ended up replacing it.
 

·
Registered
Joined
·
1 Posts
Question my bike doesn’t have the pump on it someone plugged it my bike runs good but wants to bog out sometimes and I have to flutter the throttle an help it past it like it’s loading up with gas now that I’m seeing this post I’m thinking that’s the problem I had no idea it even had one or was supposed to have one until today and I’ve owned the bike and ride it everyday for six months now 🤦‍♂️
41917
 

·
Moderator
Joined
·
973 Posts
If your bike is not leaking gas then your problem is probably not related to the problem discussed in this thread.
If it only occasionally bogs, you have to bear in mind it is a two-stroke without a whole lot of torque. If you get caught in the wrong gear and hit the gas, it will bog. They did this even when they were brand new and as they age it gets worse.

However, it never hurts to rebuild the carb, put a new spark plug in and check the compression. And de-carbonize the muffler too.
 
1 - 8 of 8 Posts
Top