Carb advise

willy · #1 06-17-2009, 09:58 AM

Seems my 1992 Yamaha 150 has developed a disdain for staying running at idle.
sometimes it does, about 2/3 time it won't.
I am assuming I have a fuel delivery issue going on. Fresh gas and filters has made no difference.
Above idle runs great, with choke applied it idles, rich but idles.

so I am planning to do something I believe looking at it this engine has never had, a carb rebuild, 17 year old motor and sh!t gas ethanol. I am also planning to replace fuel pump.
So the question is this, if you have never done it is it hard to remove, rebuild and install this carb set up and do I need anything special tool wise to do it?
I have done the fuel pumps on other motors so not worried about that, just dont know if it is worth me(stupid) playing around with the carbs from a safety stand point or should I take them to someone who does it for a living?
Money is tight so I would like to do it myself

Blue_Runner · #2 06-17-2009, 12:08 PM

I've been through mine twice. I was scared at first, but a friend had been there and done that with his 150 yami so he agreed to let me pull it in his dad's shop and show me the ropes. I did not rebuild though, just cleaned everything with carb cleaner. It wasn't so bad at all. If you are just cleaning you have to be careful with the gaskets. As with anything else just remember what you take off and put back the same. You have my vote of confidence....for what its worth.

I wasn't having an idle problem. Mine would not reach full RPMs b/c a small bit of trash was clogging a jet not allowing fuel to one cylinder.

What year is your? My buddies is a '94 or '95 (I think) while mine is '04. They are basically the same motor under the hood best I can tell.

tsubaki · #3 06-17-2009, 03:00 PM

willy, I'd do like Blue said, try cleaning the booger(s) first and see what goes on after that.
I've seen a lot of paid by the hour, sure nuff outboard mechanics, fail to clean the jets and other orifices and end up with the same problem they started with.
And clean the holes and jets with an acetylene tip cleaner or the like, just spraying cleaner won't do.

willy · #4 06-17-2009, 04:18 PM

A fellow I know suggested that I should first pull the power going to the plugs, then disconnect the interupt circuit so I can open the throttle to WOT and crank the engine spraying carb cleaner in there heavy, then let it sit for about 15 min then do it again.
He says better than half the time that cleans out enough junk so you are back in action, then do a tear down over the winter.
Is that what you guys are talking about doing?

tsubaki · #5 06-17-2009, 04:31 PM

I'm talking about removing the carbs, removing the bowls and start cleaning after that. Usually you can do all of this without damaging a gasket or seal.

willy · #6 06-17-2009, 04:58 PM

Tsubaki if you go that far why would you not just do the rebuild?

Skools Out · #7 06-17-2009, 05:49 PM

i do mine every spring that way too, no rebuild i just tear them apart clean all the brass and metal parts in laquer thinner and the rest i clean with mineral spirits, works great never have a carb issue, that's what i would do if i were you.

willy · #8 06-17-2009, 07:45 PM

That cleans the needles the jets, low idle circuit etc doing it that way Todd?

phatdaddy · #9 06-17-2009, 07:54 PM

willy, i pulled the carbs on that yamaha i bought last year and it was no biggie. they are very simple to tear down and reassemble. just make sure to mark the bowls to the tops if you take them apart all at once. also sierra makes a kit for them with gskts for not very much.

RWilson2526 · #10 06-17-2009, 08:39 PM

I was exaclty where you were at early this season.....after flip flopping back and forth I finally didnt have the guts to do myself ...cost me $475 for a rebuild (+ $40 he charged for a link and sync as he said someone prior to me had been monkeying bad with the carbs)....next time I might go for it on my own.... but it was kind of nice dropping it off and picking it up done....