F40 Yamaha No Power

R

RMunger

Recruit
Joined
May 27, 2007
Messages
3
My F40 won't stay on plane for more than 15 seconds or so. RPM drops to 2900 and runs rough. Suspected float needle wasn't seating and bowl was flooding. I went on the cheap and bought a single float valve and replaced it. Now it runs great at all RPM's when connected to a garden hose. When I put it in the water, 2900 RPM tops!! I plan to rebuild all 3 carbs. Does this sound reasonable given the symtoms? Any tips on how to do this without breaking the bank? Who sells kits the most reasonably? Also, I was shocked at the cost of parts. Particularly the o-rings. Yamaha wanted $12.00 EACH!!! Has anyone found an alternative?

I have purchased a manual and now have issues on special tools. Yamaha lists part numbers but won't sell me the tools! Example, I want vacuum gauge to sync carbs. No will sell! Can I get any vacuum gauge? Are ports 5 or 6 mm...or something different.

Using a digital multimeter presents issues also when wanting to check electrical components. They say I need a high voltage adapter. Can I make one...does anyone else sell one? Lastly, on the fuel pump. Looks like suction pressure measurement is recommended. Why not discharge pressure.

Sure hope someone can help!

Bob
 
R

Ray Neudecker

Lieutenant Commander
Joined
May 25, 2004
Messages
1,656
Re: F40 Yamaha No Power

First step would be to rebuild the carbs and set at factory specs.
 
R

RMunger

Recruit
Joined
May 27, 2007
Messages
3
Re: F40 Yamaha No Power

Thanks Gentlemen.

My old radio shack multimeter is due an upgrade so I will get a DVA like the Stevens CD-77 to do my electrical diagnosing. I'll check the local auto supply houses for the vacuum gauge set-up. I will order the rebuild kits today.

Suggestions of the best mail order place? Just a little internet looking suggests there isn't $10.00 difference in most places.

Lastly, are people really spending $12.00 each for o-rings? Boy am I old and out of touch!

Bob
 
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