Husky Fuel Issue

[MountainMoto]

I pulled the husky (SM610) out this morning to ride it to work since I hadn't been on it in over a week. Started up and ran fine for about a block (the bottom of the hill) then it sounded like it was running out of fuel.
I pulled over and checked, half a tank, but even though it was idling fine it would stall if I tried to rev it. Had to push it back up the hill.

Since it's an older ('06) carbureted version I expect that I'm not getting enough gas from the tank to the carb. Anyway, I was wondering if there is a fuel filter or screen in the tank that could be clogged or anything else I should check before I dig into it. I expect it's clogged in the tank or in the carb. Any idea's from experience that could save me some time would be a great help.

Thanks in advance.

[Goosedog]

I think it would be unlikely the petcock filters could be clogged enough to starve to carb, could it be your hotstart was accidentally pulled out when you grabbed for the choke?
Hotstart out, it runs super lean like running out of gas.

[MountainMoto]

I think it would be unlikely the petcock filters could be clogged enough to starve to carb, could it be your hotstart was accidentally pulled out when you grabbed for the choke?
Hotstart out, it runs super lean like running out of gas.

I didn't think of that, but no. Not the problem.

Any other smart people out there?
I might get a chance to look at it tonight.

[Jmoore12]

As stated, hot start, petcock position are the first two I would check. We have all done it.. left the petcock on prime or off and scratched our heads for hours.

Did you recently fill it up? Could be bad gas, hope you didn't put diesel in it. Take the tank off and shake the gas around, pour it into a seperate container and try fresh gas. also drain your carb bowl via the screw on the bottom.

[restukey]

There is a drain tube at the bottom of the bowl with an allen head screw that will allow gas to drain out of your carb. If you loosen the screw the gas should flow pretty freely out of the tube. You can also hold the tube up to check the float height on your carb while very very slowly unscrewing the allen head to get a slight trickle. There might still be the magic marker mark on the bowl where kehin set the float. If that mark isn't there or has worn off, the height of the gas when the tube is held up vertical should be around the height of the bottom of the four black allen head screws that hold the bowl on, maybe a smidge higher. The flow of gas should only very slowly fill the tube or your not going to get a good reading.

The pilot jet should have a nice well defined bright round hole when viewed through a loupe or magnifying glass up against light. You shouldn't see any other fringes of color like red or blue, that is gas laquer building up in the pilot.

I had some issues that I thought were gas earlier this summer. It turned out that my CDI was going again. I am on the third one. You can check the spark. The color should be whitish blue and not yellow. If it's yellow, you can look for something grounding, which normally happens behind the headlight. I had problems with the headlight and then the CDI went bad on me. Good luck.

[MountainMoto]

Thanks restukey. Those are some good ideas to look into. I hope it's nothing so complicated. I think I'll have time to look at the bike tonight.
Last night I had to get the tail light on the Duc working again. Why does everything break at the same time?!!

[MountainMoto]

Part two.
I finally had some time to pull it apart. Gas was flowing freely to the carb so the problem must have been inside.
I pulled the carb and pulled the float bowl off. Very small amount of grit in the bottom of the bowl. Everything else looked OK. Accelerator pump would happily shoot gas in my eyes.

I pulled the float and the valve pin. Sprayed carb cleaner throughout. Then put it back together.
Since I didn't see anything obvious I figured more testing was needed.

Before I put the tank back on I pulled off the stopcock since it wasn't shutting the gas all the way off. I removed the lever part and saw that the rubber seal on the inside is kinda messed up and a couple little chunks are missing.

Since the rest of the bike was already back together I put the tank on and tried it again. This is what I found...

I can rev it up and hold it at a high RPM with no issue, but... if I snap the throttle open the engine dies. I could ride up and down the street but if I snapped the throttle it would sometimes hesitate. So... something is still wrong.

Open for comments....

[Goosedog]

If there was dirt in the bowl then I'd remove and blow out your jets. It sounds like a bottom end problem but since you said your AP is functioning then I'd suspect the pilot jet as being plugged up.

[MountainMoto]

Yes, I think it's going to have to come apart again.
I just don't want to take it completely apart, but I don't know where all the holes go. I wish I had a diagram for it.

[xNORCAL2500HDx]

Gotta use a compressor to clean these things out. I learned the hardway.....What carb is on that bike.....Keihin 41 mx???

[MountainMoto]

Gotta use a compressor to clean these things out. I learned the hardway.....What carb is on that bike.....Keihin 41 mx???

Yes, the owners manual says ... "Keihin FCR-MX 41".
I'm having problems with my foot so I haven't been able to pull the carb again. Maybe today.
So I'm still open to ideas.

[MountainMoto]

Well, I think I know the source of my problems. I didn't open up the pump last time because I knew it was pumping.
Now, I guess I need to get me some parts? Anyone know if this carb is used on any Jap. bikes? The husky dealer is over an hour away.

[Goosedog]

Wow, I've never seen an AP diaphragm (spl?) get eaten up like that...bad gas?

[MountainMoto]

Wow, I've never seen an AP diaphragm (spl?) get eaten up like that...bad gas?

I have no idea.

[restukey]

Try a Honda dealer, crf450 uses the carb. I think there is another small o-ring not pictured, don't lose it, but I could be wrong about that?

Race gas?

[MountainMoto]

Try a Honda dealer, crf450 uses the carb. I think there is another small o-ring not pictured, don't lose it, but I could be wrong about that?

Race gas?

Yes, the other o-ring is in the cover.
No, just pump gas.

[Fyrflyer]

Here is some info.. full on breakdown of the carb in a PDF file:
http://www.keihin-us.com/am/products/fcrmx.php
and here is another site with break down and I believe part numbers
http://www.motorcyclecarbs.com/Keihi...Parts_W315.cfm

[madcowgt]

I'm pretty sure that a lot of bikes use that carb. I'm pretty sure that the accelerator pump cover on the honda FCR carbs is different, dont know what that says about the pump mechanism itself

[MountainMoto]

OK, got a new diaphragm.

First I went to the KTM dealer since I knew some KTMs use this carb. The parts guy says all he can do is order the full rebuild kit for just over $90. He can't find any other listing.

So I go over to the Kawasaki dealer and have a couple guys rifling through the books. There was a Kaw dirt bike that used the 40mm a few years back. We guessed the 40 & the 41 (most likely all sizes) used the same one so I ordered it (for $14)

I came in today and I picked it up. Exact match. Package reads Kawasaki Genuine Parts Part Number 43028-0006.

Tomorrow we'll get it back together and give it another try.

[MountainMoto]

It came in today and I picked it up. Exact match.

I spoke to soon. Almost an exact match.
Fail! This diaphragm will not work. Now, back to finding one that will.

[xNORCAL2500HDx]

I know the newer Honda 450R's use the same exact carb....I can call my boys at Fremont Honda kawi and see if they have it in stock. If so I can use my discount Cost +10% and send it via usps priority....could have it in a day......lemme know.

[MountainMoto]

I know the newer Honda 450R's use the same exact carb....I can call my boys at Fremont Honda kawi and see if they have it in stock. If so I can use my discount Cost +10% and send it via usps priority....could have it in a day......lemme know.

Thanks for the offer.
I just talked to the parts guy at GP Motorcycles in San Diego. They have the diaphragm I need and are going to mail it to me.

[xNORCAL2500HDx]

awesome......