Yamaha 2~ 6hp 1986 2 cylinder longshaft OB Help!

OGITD

OGITD

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Hi All,

Any good experienced Yamaha specialists re: 2~, long shaft, 6hp (detuned 8) 1986 model?
Sat on the transom for over 12 months, run several times to running temperature and all OK. Sat on support bracket in the shed over winter. Striped the leg as it was only producing a (to be kind) dribble out of the tell-tale. This resulted in the discovery in a fragment of the old impeller at the top of the water channel at the point of entry to the jacket. Removed fragment and reassembled, now pumps like new, with only the pull cord (doesn’t need to run / fire to give full bore out of the tell-tale).

Now refuses to start unless you literally pour fuel into the air intake.
All jets blown through and clean.
All diaphragms checked, no holes or tears and in the correct orientation.
Float moves freely.

Any good sensible ideas would be very much appreciated, and once the issue is resolved it will allow me to assist others in the future with same problem.

Thanks for any help with regards to this.

OGITD’s
 
Obviously little wrong with the ignition as it starts on fuel direct into the intake.

Must therefoe be fuel problem. Tried new fuel?

Fuel filling float chamber when primed with the bulb?.

Faulty fuel pump would result in it petering out a minute or so after starting.

If it were mine I'd be stripping and cleaning the carb again. It may be necessary to poke sometng through the jets. I use a soft copper wire but others will throw their hands in the air in horror.
 
Thanks Vic,
I’ve removed all jets and blown through everything with a can of compressed air.
An old pal mentioned tonight that the smallest of pin holes in any diaphragm can cause serious problems.
So next is to (again) go through the carb strip, blow through & rebuild while I’m going to order a new set of diaphragms for the fuel pump & take it from there.
I thought I had sorted things out today when I had it running (started and stopped several times) then applied a Quicksilver Power Tune, started & stopped a couple more times to ensure this was not a fluke.
Transported to test tank at the club for a run as per Quicksilver instructions only for it to become a none starter.
So back to the home shed & test bucket.
 
I have an old Volvo Penta outboard. (not now used!) but when that got some water in the carb and dried out the only way I got the slow running jet clear was to poke a bit of fuse wire through it. Hence my suggestion. I think I took it out three or four times before I sorted it.

If the fuel pump is faulty it should still start provided you fill the carb with the bulb and then you'd probably be able to keep it running by gently pumping the bulb.
 
Fuel filter ... good point.
I would assume though that a 6 hp has a remote tank therefore no tap but there will be a filter somewhere either integral with the fuel pump or carb or an in line one in the "plumbing". The owners manual should indicate. There may also be a coarse filter on the pick up from the tank.
 
Thanks Guys,

Inline filter clean and allowing full flow in correct direction.
Fuel from tank used during Boatlift (duty Tug & Taxi) on a Johnson with different / specific fuel connector (first time start every time).
 
It now works first time every time.

“Wynn’s Carb Cleaner” did the trick + yet another strip & thorough spray of every component and removed jets.

Do wear goggles when blowing through with said cleaner as the blow back stings the face, also remove rings as when it gets under the metal it starts to burn the skin.

But to be on the safe side I have today ordered a service kit at £28 + vat. Apparently it comes with all jets and seals inc float valve.

Thanks to all for advice and I hope this thread / post will be of use to others.

OGITD’s.
 
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