Yamaha Workshop Manual

Hi Guys,

Anyone out there got a workshop Manual I could borrow for Yamaha engines? I am trying to diagnose a bogging down issue for my brother in law and am struggling a little.
Engine is a Yamaha 30AE 1983. I believe the Mercury and Mariner Engines of this vintage use the same Yamaha Japanese powerhead and carbs, so these manuals might be of help as well if anyone has one lying around.

For those that might have an idea of the problem, the engine runs fine in idle or fast rev in Neutral. When I try to apply power when in gear it is bogging down. This seems to only happen after a few minutes as the first run seems ok.. This was an intermittent problem that seems to have gotten worse over the previous 2 outings......
It's driving me nuts!


Thanks Guys,

Kev

It sounds like a fuel problem, check the air breather screw on the tank, the fuel filter/fuel pump and the pump bulb to see if it's soft or been sucked flat. There may be enough fuel getting through to run in neutral but not when the load is put on, also run a bit of carb cleaner through and see if that helps.
Check that the prop turns ok in neutral and that there is no line wrapped around the shaft.

Here is a basic manual http://storage.vuzit.com/public/4en/source.pdf

Good luck.

hi kev, im wondering could the middle needle in the carb be blocked. could be caused
by previous owner leaving fuel in it over winter. I had this problem once, it would rev
fine out of gear as the small needle was not blocked, would not work when the load came on

sounds like it might blocked main jets.

Thanks for all the suggesting lads. I put that post together in work and should have mentioned some of the things I have tried. I have fitted a new carb kit, which included a new float and needle valve. I also cleaned the carb with carb cleaner, including the jet... TBH, it didn't need doing. The carb looked in excellent condition. I even put some tune up spray through the carb..... I then tried the fuel pump. I did get a little gunk out of it while cleaning it down by spraying some carb cleaner into it. I didn't want to take it apart as I don't have a replacement set of diaphragms and gaskets...., but the problem persists, even when I manually pump the fuel primer bulb, which suggests to me it's not the pump..... Deffo a fuel problem for sure, so I'm back looking at the carb again. A little stumped on this one.... and am starting to think maybe the carb is not balanced correctly, so hence the request for a manual....

Thanks again for all the input lads.

Kev

Try here Kev , you can get PDF versions really cheap. i have used it before and it works really well. You pay with a CC or paypal and you are emailed a link to download the PDF.

Works great

http://www.readmanuals.com/outboard.motors/yamaha/

Not sure if they will have back to 1983 but might be worth a look

I have the manual for 40 - 115 hp mercury 1965-89 if thats any good to you.
You could also get a lone of another tank and fuel line and bypass your system up to the carb just incase.

Excellent link Adam. Nothing for my engine through.

Cheers for the suggestions fergal. That was next in line. I managed to find some info online for the correct air mix setting on the Carb. This was fully seated and 1 & 1/2 turns out. This made a nice difference to the idle speeds, but did not help when I tried to apply power. I am also going to check compression and timing when I get a loan of the tools.

This one is getting under my skin.....