Hi All,

Was hoping to get some input on diagnosis of this problem from other Kodiak or Yamaha 4x4 owners. I've recently started having a gas flow problem on my 2005 Kodiak 450. I've not had one minutes trouble out of the bike until now.

It first started 2 weeks ago after a bout crossing a small creek (not deep, maybe 6 inches of water) and hitting a decent hump incline on the other side. Had to hit it pretty hard to get up over the hump, but bottomed out near the top, then the bike stalled. It's never stalled before. Got it cranked back up, towed off, then rode for another 10 minutes or so when bike started sputtering, then just died.

Let it cool for 5 minutes, checked plug, had spark and wasn't wet, but changed it anyway to a new one. Opened the carb drain tube screw, gas flowed out. Cranked it again and started right up. Strange right? Decided to call it a day and rode 5 miles back to the trailer. Got home and put a new in-line fuel filter on it thinking the old one might be getting clogged.

A couple weeks later, was using it to pull an aerator around the yard, and after about 30-40 minutes, bike dies again. Pulled side cover and could see there was no gas at all in the fuel filter. So it's obviously a gas feed problem.

Emptied fuel tank, took out and disassembled gas petcock, checked for clogs, but had good air/gas flow, no obstructions on inside tank main or reserve filters. Put in new gas. Got it all back together, gas was flowing fine again, filling gas filter, all seemed fine. Rode another 20 minutes, died again, same thing.

So, me and a buddy pulled the carb took it apart and cleaned it good. There was only a tiny bit of dirt in the bowl, nothing visually obstructing any holes. Put it back together, started right up, rode 5 minutes, seems to be fine. But, haven't rode a good lenght of time to see if it's fixed.

Anyway, has any other Kodiak owners experienced this problem of gas not flowing before? Does this sound like symptoms of float needle problems or is it a vapor lock issue? Seems to only lose the gas flow after it's warm and running a while, but maybe that's just coincidence. Any input welcome. Thanks for the read.

Arg

 

I have not had this problem, but I would check your gas cap vent tube. If it is clogged, air can not flow in as gas flows out. After a while gas can not flow out until you let the air in. Removing the gas cap fixes the problem for a while.

 

Thanks for the tip, Traildad. I had actually already checked that yesterday. Took the cap assembly apart and checked that there were no obstructions to the vent tube or the little ball. The whole cap and tube were squeaky clean and air flows well through it.

So yesterday I get the Kodiak back to my house and started riding it around the yard for about 10-15 minutes. It seemed to be doing fine. I had the left side panel off to check the fuel filter every minute or so to make sure gas was still flowing. Well, after about 15 minutes, the damn thing did it again! Gas stopped filling the fuel filter and eventually the carb just ran it dry like before and motor dies from lack of fuel.

So now I'm like, what the hell. I pulled the fuel pipe tube off at the the carburetor. Gas still not flowing from the tank through the tube. Took tank cap off, still no flow. Turned to reserve, still nothing. So this definitely appears to be some type of obstruction in the fuel **** assembly I'd assume right? But before it was flowing fine through there when I had the tank off the day before, really strange.

I guess for the cost of about $13 - $15 it would be best to just get a new fuel **** assembly, rather than try and clean this one wouldn't it? Maybe it's got some type of varnish buildup inside of it, or piece of dirt I guess? Anyway, that's the scoop so far. I have to get this thing fixed soon before our upcoming Hatfield/McCoy trip.

 

Whatever it is could be small enough to miss in the tank. Maybe something in the hose going from the tank to fuel ****. I once had a car that died from lack of fuel. It turned out to be a small piece of rubber fuel line floating around in the bowl. Every once in a while it would get in the wrong place and block fuel flow. It could be that there is something small in the tank or between the tank and the fuel ****. Good luck.

 

Ok, so I worked on it some more last night. First wanted to debunk the "theory" I was kicking around that somehow the gas was vaporizing or something when the motor was hot. Tank was more than 1/2 full of gas. Turned open the gas valve, no gas would flow with motor cold, either normal or reserve. So that stupid theory didn't fly, which I figured as much anyway.

So now I'm getting frustrated. I took off the tank again, drained it completely, and disassembled the fuel ****, again. The fuel **** is clean as a whistle. No dirt or obstruction of any kind, I can blow through both regular and reserve tubes with ease. The pipe filters were also clean. Ran a thin wire up through the tubes for good measure, then reassembled it carefully.

Stuck a flashlight in the tank and there is no dirt whatsever in it. Not even a flake that I could see and I looked it over good. Now I'm getting the "wtf" feeling, because I can't find anything wrong.

Put it all back together, fill the tank full of gas, screw tank cap on, set up the tank on some buckets so I can let fuel run through it and watch it. Attached fuel tube with in-line fuel filter, open the petcock, fuel starts running freely, perfect.

But, after about 3 minutes, the flow starts tapering off, then just stops, and tank still has plenty of gas. Here we go again! I even uncapped the tank to see if it was a vacuum problem, still no flow. So I remove the in-line filter, turn on flow, and it starts flowing again. So apparently the filter is somehow restricting the flow, very strange. Especially since I'd been running with an in-line filter for over a year with absolutely no problems.

I'm about sick of fooling with this. I guess I'll just get a replacement fuel tube and leave off the in-line filter and see if that gets it working again.

Anyway, sorry for the long post, but just thought it helpful for anyone else that might encounter a weird fuel flow problem like this. Has anyone else ever installed an in-line filter and had this type of thing happen?

 

Check your fuel line. I had a fuel line braking apart inside and it bloked flow and small piece
went in the carb.

 

Hello everyone. I joined this forum due to the description of the fuel problem described in this thread which almost exactly matches the problem I am experiancing with my 2000 Yamaha Kodiak YFM400A.

I have tried everything I can think of to resolve the "no flow" problem with no success. I have removed the carb and had it gone through by my local shop (they told me it appeared to be clean and free of any obstruction). I have replaced the fuel cap and fuel **** assembly with factory Yamaha parts. I have checked all related vent hoses to verify no obstruction...

I did add a clear plastic in-line filter in order to moniter fuel flow (which is nearly non-existant), and I almost wonder if this may be creating more of a problem than benifit? I realize this is a gravity feed type fuel system, and I wonder if the FF is creating too much resistance and not allowing the fuel to flow freely? I intend to remove the filter tomorrow and replace the OEM feul line which is the only thing I have not tried already.
Argyll, I am curious if you have been able to diagnose the source of the problem you described?
Anyone else who can give advise to this topic would be greatly appreciated!

Thanks!

 

"Argyll, I am curious if you have been able to diagnose the source of the problem you described?"

Hi Dave, sorry for the late reply, I don't get much forum time anymore.

Bottom line, no, I did not figure out the source of this problem. From everything I tried and tested, it pointed to the flow not being able to go through the filter, being a gravity fed system. The weird thing is that I had an in-line filter installed and running for over a year, then all of sudden this started happening.

I wound up just buying a new fuel tube (the one from petcock to carb), and left out the fuel filter altogether. I bought a new petcock too for good measure. Kodiak ran perfectly fine after that, no more fuel flow problems at all.

But, now I have a carb problem (just this past week). Kodiak had been sitting too much without running it. Now, it will start and run, but idles kinda rough and won't idle well. I think the carb just needs a good cleaning Oh well, that's how it goes I guess.

Argyll

 

the fuel filter is sacrificial to the fuel, it dirties its self to clean the fuel. so when you have had it on there for over a year chances are that it is clogged up that it cannot flow enough fuel, so in turn when you had the machine running and it would die after about 20 minutes, it was just the fuel line after the filter and the bowl emptying out. also i wouldn't suggest running without a fuel filter.

 

Read my post as I had the same problems, it took some time but finally found the problem on my Kodiak.

Keep on 4 wheeling