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Discussion Starter · #1 ·
Hi guys i need some help if possible I have a 2008TRX420fm lately the engine has been cutting out
it only seems too hapen if i leave it idling for a while or if i am driving around realy slowly for along time or on long hard drives

It always starts first go (matter of seconds after stopping )
again and goes for a short time (seems too get worse (as in more frequent )as the bike gets hotter ) and then cuts out again

The longer i leave it too cool down the longer it will stay going for before staling again

Seems like maybe there are some relay contacts or some thing along those lines that might be heating up and seperating and breaking a circuit until they cool again

Have disconected most of the electrical conection blocks and reconected and took for drive but happened again

Was wondering if anyone has had same problem or any ideas whats wrong would appreciate any help


Thanks in advance Mudda
 

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2008 420 Rancher Stalling

Dear Mudda,
We have been having the exact same problem!! Same scenario, same symptoms, everything! We have contacted the honda dealer and they are telling use we need a new fuel pump. Yet when it's running at full speed it's running great only seems to be when your idleing around or at slow speeds so we are doubting it's fuel pump related. Were thinking vapor lock issues, but also agree with the electrical connection theory...or electric valve???
We ordered a new fuel pump and will give that a try and keep you posted. Let us know if you find anything out!
Aggrivating damn thing isn't it :icon_cussing:
 

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I don't have much experience with the fuel injected models, but the fuel pump would have been my guess as well. But it's just a guess.

It could be vapor locking, though. Now that I've reread your post, those sound a lot like vapor locking symptoms.
 

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Discussion Starter · #4 ·
stalling 2008 420fm

Dear Mudda,
We have been having the exact same problem!! Same scenario, same symptoms, everything! We have contacted the honda dealer and they are telling use we need a new fuel pump. Yet when it's running at full speed it's running great only seems to be when your idleing around or at slow speeds so we are doubting it's fuel pump related. Were thinking vapor lock issues, but also agree with the electrical connection theory...or electric valve???
We ordered a new fuel pump and will give that a try and keep you posted. Let us know if you find anything out!
Aggrivating damn thing isn't it :icon_cussing:
hi dam-man mudda here meant too get back too ya sooner but havent had a chance just wondering have you had any luck sorting out your stalling quad i havent had time to do anything with mine since was wondering what you meant by vapour locks I would be inclined too agree with you that its not likely to be the fuel pump And your right it dam sure is agrivating
 

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Discussion Starter · #5 ·
I don't have much experience with the fuel injected models, but the fuel pump would have been my guess as well. But it's just a guess.

It could be vapor locking, though. Now that I've reread your post, those sound a lot like vapor locking symptoms.
hi helmut meant to reply sooner but no chance thanks for the reply just wondering what you meant by vapour locks and how would i go about sorting it out thanks in advance mudda
 

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Vapor locking is caused by the heat from the engine, heating the fuel inside the fuel lines, causing the fuel to turn from liquid to vapor. When the fuel turns to a vapor in the lines, the fuel pump can't pump the fuel.

Next time it cuts out, try taking the gas cap off and see if it makes a difference.
 

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Discussion Starter · #7 ·
Vapor locking is caused by the heat from the engine, heating the fuel inside the fuel lines, causing the fuel to turn from liquid to vapor. When the fuel turns to a vapor in the lines, the fuel pump can't pump the fuel.

Next time it cuts out, try taking the gas cap off and see if it makes a difference.
cheers helmut will try that at the weekend if i get a chance Iwill let you know how iget on
 

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Try replacing the pick-up filter inside the fuel pump.When it's plugged up,it will cause the fuel pump to overheat.If you run it too long that way,it will burn the fuel pump out.Honda has a fuel filter kit for these pumps.
 

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Mudda, what was the outcome? Was the problem solved? I have the same issue. I have replaced fuel filter, checked vent cap, and spark plugs are clean. It still stalls out every 10-15 seconds. It doesn't matter incline, speed, throttle changes, gear, etc. It doesn't stall at idle.
 

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Hi Mudda, Dam-Man and Postal,
I am having the exact same issue with this 2007 Rancher 420 that I just bought a few weeks ago. It runs and throttles fine...perfect up until the fan motor comes on (about 10-15 minutes of riding) and then it starts cutting out and bogging down.

What was your resolution on your issue you posted above from 2010 ?

Thanks much, any insight would be appreciated. Mofolks
 

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Discussion Starter · #12 ·
Hi there I replaced my fuel pump and it was fine for about a year or so but it has started doing it again so I guess I will have to get another pump seems to be the fuel is vaporizing as Helmut said and just to add salt to the wound the bloddy starter has packed it in so was wondering is there a kit that can be got to repair them
 

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Hi there I replaced my fuel pump and it was fine for about a year or so but it has started doing it again so I guess I will have to get another pump seems to be the fuel is vaporizing as Helmut said and just to add salt to the wound the bloddy starter has packed it in so was wondering is there a kit that can be got to repair them
yes..you can buy starter brushes off ebay.
 

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Stalling when hot only.

Hey Folks. I have a 2011 TRX420FM and yesterday experienced the exact same problems(stalling when hot,but idles fine when stopped and cooled down for a short period). I only have 600kms on this machine and always use premium gas ands keep it full. I was thinking vapour lock right off the start but it was cool on the long drive yesterday. Please keep posted on the solution. I will explore the filter kit option first I think. Kevin
 
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