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O.S. FS Series 91 Surpass Weird problem.

Old 07-06-2014, 02:44 AM
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gkpain
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Default O.S. FS Series 91 Surpass Weird problem.

Hey Bax,

The motor does seem to pull fuel from the tank unless I block the muffler.
The plumbing and the fuel tank are ok and have no leaks.
The motor will start and run until it runs out of prime then quits.
If I block and regulate the exhaust port it will stay running.
Sticking exhaust valve>? maybe>?
Any ideas>?

Thanks,
(GK) PAIN!
Old 07-07-2014, 06:33 AM
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Bax
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It sounds like you're just not getting fuel to the carburetor. Low fuel pressure can be caused by a too-large tank, obstructed fuel lines. trash in the carburetor, low intake suction, a bad needle setting, and so on. Also check the muffler to make sure the tap isn't obstructed with some kind of trash. Your best bet would be to put the engine on a test fixture and run it with an absolutely-new fuel system. You'll be able to see if the problem's in the engine or elsewhere.
Old 07-07-2014, 03:30 PM
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gkpain
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Thanks Bax,
I found that the low end needle was very closed, so I referred to the manual and set the needles both hi and low to the suggested starting points.
And Wa La the engine runs fine! After adjusting the hi end at max rpm, the low end needed alittle tweaking for a smooth transition but not much.
Thanks again
(GK) PAIN!
P.S. did the same thing to my ys 140 and Wa La and it runs fine too
Old 07-09-2014, 06:20 AM
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Bax
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We're glad you found the difficulty and that it was something simple. Unfortunately, the simple things are also easy to overlook. Don't know how many times we've missed simple things on the first go 'round.

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