Mechanical HELP 25hp Johnson
Hi all, just wondering if anyone can give advice on an issue we are currently having with a 25HP johnson motor. The motor starts fine and runs perfectly on plain for about 3 or 4 hundred metres and then starts to kick and the motor loses all power. U can then turn the motor off and start immediately and then your off again, same issue about 300m down the track. When I say kick the motor seems to cavitate back and forth and you are forced back down to an idle!!
We seem to think that a build up of air or petrol flow may be an issue. Nothing stands out!!
Any help will be appreciated!!
P.S Spark plugs have been replaced and the topic of water in fuel has been discussed however would have thought the motor would run like $##@ from word go!!
D_DOUSH
Posts: 497
Date Joined: 23/12/07
Sounds like a fuel flow
Sounds like a fuel flow problem to me, probly stupid question but have you undone the air flow nipple on the fuel tank?
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Adam Gallash
Posts: 15610
Date Joined: 29/11/05
fuel line
Have you taken your fuel line off lately, make sure you've got it facing the right way. Had a similar problem in the early days of my tinny and didnt even think about it. If fuel line is the wrong way, will allow a certain amount of fuel through - cuts out, builds pressure again, goes, cuts off. Probably not the solution, but worth a look.
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scano
Posts: 1246
Date Joined: 31/05/07
fuel line to motor?
I had an issue with my last Johnson outboard that according to the dealer is pretty common. There is a black plastic fitting that links the main fuel inlet line to the carburettor. It is about the size of a 50c piece and has a hose fitting attachment in the middle of it. They often develop a hairline crack in the plastic fitting and therefore suck air and make engine's run lean or stall.
The part was all of about $7 and the motor ran like a dream as soon as I replaced it. The way to double check all of your fuel lines is to prime your hand primer / pump until it is completely full and hard. Keep the pressure in the line by constantly squeezing the primer bulb.
Then using a torch inspect all of the fuel line connection points right up to and including black plastic carby / fuel line connector. They run a thin rubber gasket behind this plastic fitting that can often fail as well.
hope this helps
scano
Spooled
Posts: 486
Date Joined: 06/08/05
Cheers for help
Cheers Guys for your ideas and help. We have tried a few things. The full line to the motor is a little stuck at present on the outboard end. I have come across that prob before Ads on James outboard. Will suggest to old man when fuel line is set free. Scano I know the part you are talking about was looking at that today. Was a little worried a bout pulling off just incase it had a #$#$ load of springs like the old Johno outboards had about ten years ago from memory.
Many thanks again guys for your help!! Will let u know when prob is resolved. Will try the fuel line reversal Ads!! The fuel line does have a couple of suspect cracks appearing very tiny, though could be the issue