Fuel related questions: 95m900

needtorque · April 21, 2009, 03:39:29 PM

Just a suggestion but try replacing the vacuum petcock with a mechanical one. I just went to a moto bone yard and got one off an old bike and used that. Maybe the one you have is intermittently sticking. Replace all fuel line if you have never done that. These are some cheapo suggestions to eliminate possibles.

greenmonster · April 21, 2009, 04:13:43 PM

Had a fuelpump on mine hat worked about 45 mins, then I could only apply 2-3 mm throttle or it died.
Problem gone w new pump. Guess worn diaphragms in it.

Duck-Stew · April 21, 2009, 04:25:28 PM

When the bike is running well, does it seem to pull just fine at any RPM or do you have issues at particular throttle openings? If it's fine at all RPMs, then your problem is fuel delivery and not jetting.

There's a Polaris re-build kit for the old pump that's under $20 IIRC so that's a cheap fix but it would just be a matter of finding a rebuild kit.

+1 to replacing the fuel lines if you've never done so and it's not a bad idea on the vacuum pet-cock either although my own luck w/vacuum petcocks has been stellar...

erkishhorde · April 21, 2009, 05:00:26 PM

So where can I get hose for the fuel lines? I doubt just any old hose from home depot will work, will it? After looking at it I was considering getting some longer line so that I can move the fuel pump a little bit so that it doesn't touch anything except it's 2 mounting points even though I don't think that will solve the problem it will look a lot better.

What's a vacuum petcock? I've got an old fashioned fuel petcock between the tank and the fuel pump.

I just replaced the fuel pump half a year ago with this guy from CA-cycleworks.

I'm hoping it's still ok. Even though it was only $27 I still would rather not replace it right now.

In response to Stu, lower gears seem fine over all RPMs but even when it's not having problems, the bike doesn't like 70mph in 6th gear. Started noticing this when I switch to 15/43 sprockets from 15/41 a while ago but didn't think much of it. I'm not sure what RPM this is since my tac is broken. I found that a bit odd since I didn't notice any problems when I was running 15/41. I could cruise at 70mph in 6th and still accelerate just fine with little throttle input but when I switched sprockets there's a big flat spot of power on the lower end of 6th gear. It's not quite lugging, it's just got no power and I really have to gun it to accelerate in 6th gear at 70mph.

I wonder if I can dig around in the carbs on my own or if it's over my head.

Duck-Stew · April 21, 2009, 08:43:48 PM

Ok, if you've got the manual petcock, then never mind that going bad.

As far as your carbs go with the gearing and lack of power @ 70mph... maybe your needle-jets are oval-ing out some. Can cause odd problems like what you're describing but that wouldn't have the effect of the bike dying out when hot...that's a different issue.

As far as replacing hoses goes, try an auto parts store before a Home-Depot and a motorcycle shop (not a dealership) before an auto parts store.

Can you post up a pic of how your fuel pump is routed/positioned?!? That may yield clues...

needtorque · April 22, 2009, 04:35:56 AM

Quote from: Duck-Stew on April 21, 2009, 08:43:48 PM
Ok, if you've got the manual petcock, then never mind that going bad.

As far as your carbs go with the gearing and lack of power @ 70mph... maybe your needle-jets are oval-ing out some. Can cause odd problems like what you're describing but that wouldn't have the effect of the bike dying out when hot...that's a different issue.

As far as replacing hoses goes, try an auto parts store before a Home-Depot and a motorcycle shop (not a dealership) before an auto parts store.

Can you post up a pic of how your fuel pump is routed/positioned?!? That may yield clues...

Definitely auto parts store for fuel lines. The petcock suggestion was simply b/c I have heard other say theirs have failed but if you have a mechanical then nvm. (I have never had a problem with the vacuum ones either)

Howie · April 22, 2009, 05:10:06 AM

Here is an easy way to prove to yourself the problem is fuel delivery. Carry the appropriate size wrench with you and see what comes out of the float bowls after you run out of power.

http://ducatimonsterforum.org/index.php?topic=22384.msg399317#msg399317

As far as the heat goes, low fuel delivery, low float height. Low float height, lean mixture. Lean mixture, more heat. If the problem is heat related, enter Catch 22.

For test purposes you can bypass the fuel pump. The bike will run on gravity as long as the level in the fuel tank is higher than the carbs.

Norm · April 22, 2009, 07:25:35 AM

Bypass the filter and fuel pump with new lines and go for a ride.

erkishhorde · April 22, 2009, 11:31:28 AM

Gonna go get fuel lines today. We'll see if I get around to swapping them out. The bike's my only mode of transport right now so I gotta give it time to cool down after I go get the parts.

This is how my fuel lines are routed. They rest on the belt covers a bit and in the front where they connect to the carbs? they touch the engine as the squeeze between the air box and the engine.

The fuel pump touches the frame at the top mounting point and where the fuel line out connects. Other than that it's just hanging there so I don't know why it gets so hot.

Howie · April 22, 2009, 02:26:41 PM

The routing really isn't any worse than factory. As someone who has been known to do things back asswords, could you have in and out mixed up on the pump?

erkishhorde · April 22, 2009, 11:03:23 PM

Quote from: howie on April 22, 2009, 02:26:41 PM
The routing really isn't any worse than factory. As someone who has been known to do things back asswords, could you have in and out mixed up on the pump?

Pretty sure I got it right. I installed it in Chris's parking lot in kind of a rush but wouldn't the bike not work at all if it were backwards...?

Howie · April 23, 2009, 02:49:08 AM

Quote from: erkishhorde on April 22, 2009, 11:03:23 PM
Pretty sure I got it right. I installed it in Chris's parking lot in kind of a rush but wouldn't the bike not work at all if it were backwards...?

It shouldn't work since it has check valves. If the check valves are leaking it could work somewhat. Just another (slim) possibility to check. Anyway, I have one in the garage. I should be able to compare it to your photograph later.

Howie · April 23, 2009, 04:49:18 AM

It looks like you are hooked up correctly. The arrows can be seen on the back side anyway. I doubt it will make a difference, but you might try to secure the pump.

erkishhorde · April 25, 2009, 07:14:35 PM

make the beast with two backs me!

When asked whether the diaphragm vent hoses were all still routed properly I said they were because I forgot about the one on the left side of the bike! While I was putting the air box back on after bypassing the fuel pump I noticed an extra hose with a split end right next to front mounting screw for the air box!

The dang hose split and fell off the pod.

So now my question is, what does this do? So I put it back on, think that will fix everything? Can I put my fuel pump back on? Could this hose having been disconnected cause my fuel pump to crap out on me?

needtorque · April 25, 2009, 07:17:22 PM

Doubt it but maybe someone smarter than I can chip in lol.

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Fuel related questions: 95m900