Fuel related questions: 95m900

[erkishhorde]

Ever since I started having fuel issues about 6 months ago I haven't quite had it fully licked. First it was the fuel pump, then 3 months later it was a fuel filter. The bike ran well enough after that but now I'm getting more fuel issues so I've got a few questions.

First, what's the part number of a clear non-oem fuel filter I can swap in? Also, does it make sense to need a new fuel filter after only 3-4 months?

Second, how do you go about cleaning out rust in a tank. I'm thinking I might have dirt/rust in the tank (I think it's the original) and I'd like to clean it out now to try and stop me from eating up fuel filters.

Third, can air flow cause fuel issues? I've been noticing that my bike seems to lose power when I hit heavy head wind and acts like it's out of gas.

Thanks.

edit: Problem solved on pg3 I think. 

[Stangman]

Hmm I doubt you need a new fuel filter already.

A little info would help though.  What makes you think its a fuel problem?

What mods have you done?  What exactly are the symptoms you are having?

[ducpainter]

Where are the vent lines for the diaphragms routed?

[erkishhorde]

Well, today I went for a ride with some friends. 50mi on the freeway at 80mph, no problem. Hit the twisties for about 50mi with periodic stops, no problems. Then on the way home after eating some lunch and 40mi down the freeway the bike started acting like it was out of gas and I lost power and eventually if I gave it gas it would die. Pretty much the same problem I had back when I replaced my fuel pump and my fuel filter last time. So, same as last time after I sputtered out and died on the shoulder of the highway it would start up again after I sat for a minute or so. I managed to limp another 10mi down the freeway with it dying out 2 or 3 times and luckily on the last time it died out I happened to be getting off the freeway. It didn't want to start up right away so I popped open the gas cap and then after sitting for a minute or so it started up and I did some surface riding. Seemed to be going fine but then, oddly enough, same as last time it died trying to take off from a stop light 2 blocks from home. It wouldn't start up so pushed it 2 blocks home.

Not sure if it's of note, but by the time the bike died out the last time the bike was getting extremely hot. Sitting at a light it would cook the inside of my legs and the bottom of the tank got pretty damn hot too.

I've got a strong suspicion that there is rust or something in the tank blocking fuel flow, hence the question regarding cleaning a tank.

[erkishhorde]

Where are the vent lines for the diaphragms routed?

mmm... down the right side next to the starter cable? I think. I'm not sure what the vent lines for the diaphragms are.

[ducpainter]

mmm... down the right side next to the starter cable? I think. I'm not sure what the vent lines for the diaphragms are.

You really need to remove the airbox to see them, but there are some 5/16"...ish id hoses that are connected to the tops of the carbs.

Originally they went to the pods on either side of the frame.

If the hoses aren't located in still air hoigh speed performance can be affected.

I think the hoses you're talking about are the float bowl drain hoses.

[Stangman]

Your symptoms make me think its a jetting issue.

How many miles are on your bike and when were the carbs last went through?

Before I had my carbs went through and my bike tuned, it was running pretty rich and on really hot days when I came to a stop to wait for a light it would sound like it was gonna die. (rpms dropped to next to nothing and it would stumble a bit)  After I had it tuned, my tuner showed me the old emulsion tubes and you could see they were worn and oval'd pretty bad. 

Hope you can get that problem nailed down, it sounds extremely frustrating... 

[erkishhorde]

You really need to remove the airbox to see them, but there are some 5/16"...ish id hoses that are connected to the tops of the carbs.

Originally they went to the pods on either side of the frame.

If the hoses aren't located in still air hoigh speed performance can be affected.

I think the hoses you're talking about are the float bowl drain hoses.

Ah, they're still routed into their little grey pods. I haven't gotten around to removing those pods but I eventually will.

[erkishhorde]

Your symptoms make me think its a jetting issue.

How many miles are on your bike and when were the carbs last went through?

Before I had my carbs went through and my bike tuned, it was running pretty rich and on really hot days when I came to a stop to wait for a light it would sound like it was gonna die. (rpms dropped to next to nothing and it would stumble a bit)  After I had it tuned, my tuner showed me the old emulsion tubes and you could see they were worn and oval'd pretty bad. 

Hope you can get that problem nailed down, it sounds extremely frustrating... 

Mmm... Haven't looked at the carbs since I bought the bike 5 years ago. Hmmm...

[Duck-Stew]

What leads you to believe the tank is rusting on the inside?  Are the fuel filters brown in color? 

Some of your symptoms indicate you may be on the right track there...  For as long as I've known you and that '95 M900, they've both been in CA....near the ocean.  It's entirely possible.  Get a small mirror and a flash-light and look into your tank trying to see against the walls (will likely be difficult and won't be albe to see shit).  But, check it out anyways and post up what you find or if your fuel filter is brown again...

[ducpainter]

You may as well do the POR-15 process if you think it's related to a rusty tank.

If you have large rust flakes blocking the tank outlet, which is very possible, it could explain your symptoms,

You can get a look inside a carbie tank with a mirror and a flashlight through the sender hole...

not a great look, but you can get an idea of the condition of the tank.

edit...Stu beat me to it.

[erkishhorde]

What leads you to believe the tank is rusting on the inside?  Are the fuel filters brown in color? 

Some of your symptoms indicate you may be on the right track there...  For as long as I've known you and that '95 M900, they've both been in CA....near the ocean.  It's entirely possible.  Get a small mirror and a flash-light and look into your tank trying to see against the walls (will likely be difficult and won't be albe to see shit).  But, check it out anyways and post up what you find or if your fuel filter is brown again...

That's the odd thing. When I took the first fuel filter off it didn't look that bad to me. Looked only slightly dark in overall color than the new filter I got. ( I went with another oem filter.) I don't like how I can't actually see the filter in the OEM stuff so I can't see if it's actually clogged.  I'll see about getting a mirror and seeing what I can see.

Another thing that leads me to believe that it might be something in the tank is that I always happen to have these problems up when I've about 90mi on the clock. That's only about a 1/4 tank or less left so there's likely to be a higher concentration of whatever is floating in there.

[Howie]

Check the fuel line that goes from the fuel pump to the carbs also.  Over time it can get soft and collapse when hot.

[erkishhorde]

Got a chance to try and look inside the tank. Can't see much of anything at all. There is either a bit of rust or the remnants of a sticker a little bit "back" from the from the opening on the bottom of the tank if you're sitting on the bike. There's small amounts of rust around the top opening as well. Can't tell much other than that.

I raised the tank to check my fuel line again. It was ever so slightly resting on the valve cover and I could see a bit of shiny on the hose from where it touched. I adjusted it so that it doesn't touch again. Hopefully it'll stay this time. I'm wondering if the small amount of contact that it made could have caused vapor lock when the engine got really hot. I'll take it out for an hour or two tomorrow when it's hot and see if I get any fuel issues again.

[erkishhorde]

Got a chance for a test ride today and it was a no go.  Surface street riding to do errands was fine with no problems and after I dropped everything off I went for a 55mi scoot up the freeway. That went well enough and I was hoping that I wouldn't run into any problems but after I stopped for about 20 minutes and started heading home on the freeway I noticed that I was loosing power again so I decided to call it quits and go back to my parent's place.

I seem to recall someone saying that the fuel pump can overheat and stop working. Well, when I looked at it the fuel pump is very hot to the touch. The frame is also pretty hot but not as much (larger mass, I know). How do you keep the fuel pump from getting so hot?

I also found that my vent hose for the tank got disconnected some how but I don't think that matters. The hose was surprisingly hot though considering that it was just sitting there not attached to anything. Must have been heat transfer from the frame.

Stangman mentioned carbs and jetting. How would the carbs be causing this issue?

It seems to be only occurring when the bike is hot. I think it just seemed to be related to fuel level at first due to the distances that I ride and the spacing of my breaks.