640 Fuel Pump

[gunnerbuck]

Anybody know if you can get a new diaphram for the Mikuni fuel pump on the Adventure? The dealer quoted me over $100 for the pump itself but didn't have any kind of rebuild kit listed for it.

[bmwktmbill]

Gunner,
Is there a Mikuni number on the fuel pump? I saw several fuel pumps listed on the Mikuni America web site with parts available. Did you try Sommer for parts?
KTM has to make these parts available to us.
Bill in Tomahawk, WI.

[creeper]

Originally Posted by gunnerbuck

Anybody know if you can get a new diaphragm for the Mikuni fuel pump on the Adventure? The dealer quoted me over $100 for the pump itself but didn't have any kind of rebuild kit listed for it.

I believe the Mikuni pump is the base model DF52. There are variations of this pump with one, two and three outlets. If you look closely at the pump, you'll see there are two unused (undrilled) outlets on the back of the pump and 180 degrees opposite, there is the functioning outlet.
I believe the pump KTM uses is a single outlet variation of the DF52-136. The funny thing is, when you go to the Sudco site and look it up, it's the only pump they ask you to call on rather than provide a part number for a rebuild kit.
So... I suggest you call Sudco, or a Mikuni distributor in BC.

That's all I got,
C

[DSM8]

Hey Creeper,

How does this pump work, since I dont see a return line to the tank I assume it is at a very low PSI.

Are there any provisions that would allow the use of an aftermarket pump on the bike in liu of the factory one ?

[creeper]

Originally Posted by sdmdm8

Hey Creeper,

How does this pump work, since I dont see a return line to the tank I assume it is at a very low PSI.

Are there any provisions that would allow the use of an aftermarket pump on the bike in liu of the factory one ?

31 liters per hour is the rating for the DF52. They are not like a positive pressure electric pump where a regulator might be required.
Even a small Facet electric pump will flow 32 gallons per hour.

I found a aircraft parts house that has both Mikuni vacuum and Facet electric pumps for 1/3 to 1/4 the price KTM and other motorcycle related outlets want.
The Mikuni pumps listed (single and dual) do not appear to be direct replacements for the KTM/Mikuni pump, and might require a bit of fiddling, but for $20-$30... maybe you can afford to fiddle.

In the event my pump takes a dump... I may experiment with a small Facet and an adjustable regulator. The float needle and seat on a BST40 for an Adventure is not a standard gravity flow item, but rather made for a low pressure line, (maybe why its $40) so if you could adjust pressure down to 1-2 psi, it should work. All an edjumacated guess on my part... but I tend to like Facet electric pumps and have used them extensively in the past, on bizzarro applications better not discussed here, with good success.

That really is all I have this time... really.
C

[DSM8]

Originally Posted by creeper

31 liters per hour is the rating for the DF52. They are not like a positive pressure electric pump where a regulator might be required.
Even a small Facet electric pump will flow 32 gallons per hour.

I found a aircraft parts house that has both Mikuni vacuum and Facet electric pumps for 1/3 to 1/4 the price KTM and other motorcycle related outlets want.
The Mikuni pumps listed (single and dual) do not appear to be direct replacements for the KTM/Mikuni pump, and might require a bit of fiddling, but for $20-$30... maybe you can afford to fiddle.

In the event my pump takes a dump... I may experiment with a small Facet and an adjustable regulator. The float needle and seat on a BST40 for an Adventure is not a standard gravity flow item, but rather made for a low pressure line, (maybe why its $40) so if you could adjust pressure down to 1-2 psi, it should work. All an edjumacated guess on my part... but I tend to like Facet electric pumps and have used them extensively in the past, on bizzarro applications better not discussed here, with good success.

That really is all I have this time... really.
C

Thanks as ususal for the Creep(y) advice.

[meat popsicle]

Originally Posted by creeper

... and have used them extensively in the past, on bizzarro applications better not discussed here, with good success.

That really is all I have this time... really.
C

Look a Chicken!!!

[gunnerbuck]

Thanks Creeper, I was looking at the Mikuni pumps and one of the double outlet pumps looks identical, could be as easy as swapping the guts or putting a 2-1 T line hookup. Now if the pump is rated at 31L/PH an output test of the pump should be about 1/4 -1/2 a litre per minute or do they use another formula? If the pumps output is below standard will the effect show all the time or only when the tank reaches a point below a gravity feed?

[Odysseus]

Originally Posted by creeper

I believe the Mikuni pump is the base model DF52. There are variations of this pump with one, two and three outlets. If you look closely at the pump, you'll see there are two unused (undrilled) outlets on the back of the pump and 180 degrees opposite, there is the functioning outlet.
I believe the pump KTM uses is a single outlet variation of the DF52-136. The funny thing is, when you go to the Sudco site and look it up, it's the only pump they ask you to call on rather than provide a part number for a rebuild kit.
So... I suggest you call Sudco, or a Mikuni distributor in BC.

That's all I got,
C

Has anyone else ever noticed that when creeper uses the phrase "I believe", he actually means, "I absolutely know for a fact"

[meat popsicle]

Originally Posted by Odysseus

Has anyone else ever noticed that when creeper uses the phrase "I believe", he actually means, "I absolutely know for a fact"

Some of us never get tired of the taste of sneakers... either he has or he doesn't clean up after the dog much.

[creeper]

Originally Posted by Odysseus

Has anyone else ever noticed that when creeper uses the phrase "I believe", he actually means, "I absolutely know for a fact"

I'm only slightly smarter than a rock...

[Odysseus]

Originally Posted by creeper

I'm only slightly smarter than a rock...

If that is true, I hate to speculate what catagory I am in. Dumber than a cucumber?

[Carlos M]

Nice "creepinformation" (as ususal)!

I didn't want to be without a replacement and the original diaphragm looked worn. I ended up shelling out for a complete new pump as I couldn't find a rebuilding kit.

Somehow related... I have a recurrent problem with the fuel pump that looks unrelated to the state of the diaphragm: most of the times, when the bike goes into reserve (2001 640) the pump refuses to prime after I switch the fuel manifold into reserve. I found out that I can make it prime by blowing into the tank's breathing pipe.

[bmwktmbill]

Every day I learn a new trick.
Thanks Carlos.

[meat popsicle]

Originally Posted by Carlos M

Nice "creepinformation" (as ususal)!

I didn't want to be without a replacement and the original diaphragm looked worn. I ended up shelling out for a complete new pump as I couldn't find a rebuilding kit.

Somehow related... I have a recurrent problem with the fuel pump that looks unrelated to the state of the diaphragm: most of the times, when the bike goes into reserve (2001 640) the pump refuses to prime after I switch the fuel manifold into reserve. I found out that I can make it prime by blowing into the tank's breathing pipe.

That's alot easier than putting a priming bulb in the fuel line; thanks for the tip Carlos.