Author Topic: Not an R but can someone help? (Read 3796 times)

aberegg05 · « **on:** October 12, 2014, 05:45:45 PM »

Its a honda foreman 500. New bore and piston. Idles great but every time I give it any gas is want to die. Here's a video.
http://m.youtube.com/results?q=honda%20foreman%20misfire&search_type=&uploaded=d

Usmoneylover · « **Reply #1 on:** October 12, 2014, 06:14:12 PM »

how does the tank screen filter look?

aberegg05 · « **Reply #2 on:** October 12, 2014, 07:25:43 PM »

Gas seems to be flowing well

Usmoneylover · « **Reply #3 on:** October 12, 2014, 07:44:40 PM »

My 4wd has acted like that in the past and it was trash in the fuel system. Once a carb cleaning fixed it, the other time the screen in the tank had stuff blocking it.
Was there any other changes made besides the bore and piston?

aberegg05 · « **Reply #4 on:** October 12, 2014, 07:48:41 PM »

Just bore and piston. Ill check gas tank screen and see if that'll fix it.

sheaff400ex · « **Reply #5 on:** October 12, 2014, 10:16:06 PM »

Take to air boot off the carb and pump the throttle with the engine off, looking into the carb to make sure the accelerator pump is squirting fuel. I had a foreman I worked on a while ago and the diaphragm for the pump was bad. When you gave it throttle, it died. Replaced the diaphragm and it ran great. I think this ethanol is slowing killing small engines.

Jerry Hall · « **Reply #6 on:** October 12, 2014, 11:40:16 PM »

A new piston will not cause the problem like witnessed in the video.

It sounds like it runs fine while it is on the pilot jet. Fuel is not being supplied from the main fuel circuit as the throttle is opened. I would look and see if the needle clip broke and the needle is not being raised as the throttle is opened or the main jet is partially plugged.

C-Leigh Racing · « **Reply #7 on:** October 13, 2014, 12:26:23 PM »

Back years ago when I had a mower repair business, 95% of the mower engine repairs I made, was fuel related problems. The 5% left in repairs, was a parts failure or customer abuse. Good ol pump gas & this was before they started lacing the gas with ethanol.

Heres a crazy hard to believe story, guy brought in a 230 Suzuki, had the same problem your having with yours, idle fine & you could ride it at just a little throttle above idle, but any more than that & it would die out completely.
Thinking, yeah, good old stale pump gas got the carb stopped up, but wait, why not the pilot jet first because it is the smallest.
Pulled the carb off & took apart, everything clean as could be inside, so what is the problem. Checked the main jet & I B dog, there was a grass seed stuck in the main jet & no fuel could pass.
You know the tall grass like in a field about waist high with a bunch of seeds on the top, one of those seeds is what I found.

Conclusion, how did that seed get in there, well no way it came from the gas tank, to big to flow through, so only other way would be someone put it there or just by a crazy thing that happened, be sucked up through one of those little short vent tube hoses on the side of the carb.
Thats my story & I'm sticking to it on the conclusion, so from that point on, every carb I worked on after that, got a new set of extra long vent tube hoses.
Neil

aberegg05 · « **Reply #8 on:** October 13, 2014, 07:42:34 PM »

Well I went and took the bowl off and the main jet and clean it with carb cleaner and no difference. But when I pull the choke it runs better and it will rev a little. Why is that?

wilkin250r · « **Reply #9 on:** October 14, 2014, 09:47:44 PM »

I don't know the particulars of the Honda 500 carb, so I can't tell you exactly likely causes. But the big picture is unmistakeable. You're not getting enough fuel. With the choke on, you're adding more fuel, so it will allow it to run better, but it's not enough to fix your whole issue.

I doubt it's the accelerator pump, because that would only have an effect if you stabbed the throttle quickly. You would still be able to give it gas slowly, and it doesn't sound like you can.

There is also the possibility that it's NOT actually a fuel-delivery problem, but rather a vacuum leak. Check your boots and hoses.

I had a similar problem with a Grizzly 600 last year, it idled fine while on the choke, but died as soon as you gave it gas. My problem turned out to be a plugged idle jet, AND a missing air screw, so I had both a fuel delivery problem and a vacuum leak as well. But I doubt that's your problem.

Does it idle when the choke is off?

aberegg05 · « **Reply #10 on:** October 15, 2014, 08:31:50 AM »

Yes it does but not as good when the choke is on

Hurley250R · « **Reply #11 on:** October 15, 2014, 09:02:06 AM »

Quote from: C-Leigh Racing;44473

Back years ago when I had a mower repair business, 95% of the mower engine repairs I made, was fuel related problems. The 5% left in repairs, was a parts failure or customer abuse. Good ol pump gas & this was before they started lacing the gas with ethanol.

Heres a crazy hard to believe story, guy brought in a 230 Suzuki, had the same problem your having with yours, idle fine & you could ride it at just a little throttle above idle, but any more than that & it would die out completely.
Thinking, yeah, good old stale pump gas got the carb stopped up, but wait, why not the pilot jet first because it is the smallest.
Pulled the carb off & took apart, everything clean as could be inside, so what is the problem. Checked the main jet & I B dog, there was a grass seed stuck in the main jet & no fuel could pass.
You know the tall grass like in a field about waist high with a bunch of seeds on the top, one of those seeds is what I found.

Conclusion, how did that seed get in there, well no way it came from the gas tank, to big to flow through, so only other way would be someone put it there or just by a crazy thing that happened, be sucked up through one of those little short vent tube hoses on the side of the carb.
Thats my story & I'm sticking to it on the conclusion, so from that point on, every carb I worked on after that, got a new set of extra long vent tube hoses.
Neil

I had the very same thing happen years ago on a my Warrior. Opened the carb and there was a blade of grass stuck rite in the jet!