Carb Cleaning Question

[jimf232]

Hi all,
I have a pair of 1990 yamaha 150s. All carburators were professionally rebuilt March 07 and ran great until about sept 07 when they would not idle properly and stall. Yamaha machanic repaired again in 08 but by the end of the season motors again would stall at idle. Running WOT no problems. This year I will be replacing the Alu. fuel tank and attempt removing the carbs and giving them a good cleaning using the Seloc manual, hopefully this should solve the problem. Question is, should I have to replace any internal parts?( <60 hours since rebuild) or can I just remove clean and reinstall, and will there be any adjustments that have to be made? Any help would be greatly appreciated.

 

[mgeod]

Re: Carb Cleaning Question

I just cleaned mine this weekend, no new parts . Just removed , soaked bowls and jets in carb. cleaner and blowed out real good with compressed air . I have done this on several motors. Never had to buy new parts unless a gasket or o ring was bad. Make sure you get them clean , Yamaha carbs are the most sensitive I have ever fooled with . Hope this helps

 

[Silvertip]

Re: Carb Cleaning Question

As long as you open it up, why not use new kits which includes a new inlet needle and seat. These get sticky, and it simply silly at the cost of the kits not to use them.

 

[jimf232]

Re: Carb Cleaning Question

Thanks for the feedback guys. As you may have gathered this is my first time with carbs so I'm being very cautious not to get in over my head. The fewer adjustments and diassembling I have to do, the better, but if it's necessary I'll give it a shot. Thanks again

 

[erniefish]

Re: Carb Cleaning Question

i had a 1989 175 yam,and now have a 2004,150, carbs are a routuine item,take a few pics b/fore,helps when you get a little stumped on routing of hoses ect,remember remove every screw ,orfice ect,those brass srews(jets can be tuff, use proper size screwdriver, and tap screwdriver with small hammer ,good luck take your time

 

[rodbolt]

Re: Carb Cleaning Question

myself I would check a few things.
my usage pattern first.
then make sure genuine Yamaha gaskets and fuel pumps and lines are used.
when cleaning carbs remember dirty carbs are a symptom not a problem.
the trash came from somewhere.
it simply did not materialize.
clean or relace all fuel lines on the engine.
I use a piece of kite string and pull a piece of rag soaked in carb cleaner then blow out with air.
replace the pumps as they can hold debris and pass it on for a long time.
the engine mounted filter can be updated to the 10 micron style.
replace the lines from the fuel water seperator to the engine.
make sure the fuel water seperator is a 10 micron with at least a 90 GPH flow rating(anything over 115 HP) and change it every 50 hours or at least once per year as a maint item.
if you wait until watery goo/debris makes it past the filter you waited to late and it will pass the filter.
that fuel water seperator is like a litter box, only so much poo it will hold.

 

[jimf232]

Re: Carb Cleaning Question

Thanks again guys, all your knowledge is greatly appreciated.
Rodbolt you are correct with the symptom not problem theory, I've been chasing the problem since I bought the boat 3 years ago putting off the inevitable, changing the fuel tank, which will be replaced in a few weeks. At the end of the 1st season I siphoned ALL remaining fuel from tank (finding debris and water) before complete carb rebuild. I am using Racor 10 micon water seperator filters and changed them 3x during the second season, again finding debris and water when removed. All fuel lines from shutoffs to motors have also been replaced, and mechanic tells me all fuel pumps are good.
This past fall, drained all fuel from tank prior to removal and I could not believe the junk that came out, thank you corn squezzers for ethanol!!!!!! and it's cleaning abilty. Hope that replacing the tank, changing the remaining fuel lines and cleaning carbs will correct the PROBLEM.

 

[rodbolt]

Re: Carb Cleaning Question

yep, but all the debris that went Through the pump? the pockets in the pumps can trap debris and then feed it back into them freshly cleaned carbs.
wont be the first time it happened.
your correct on squeezins, they belong in my tumbler with Ice and not in my fuel.
buy good squeezins and ice is all thats required.
it aint my fault and I did not ask for this boondoggle but I have made a lot of money off of it.
we have lost a few customers over it as well.
they simply sold the boats and are now playing with something else due to maint costs.
take the guy with a wife and 2 kids and a 17ft stingray with a 3.0 mercruiser.
if carefully maintained he can take the wife and kids out for a weekend of water sking and playing for less than 100 bucks a weekend all summer long.
cant even get in the movies for that.
now take the guy with an offshore boat with twin V6 motors that will go 20-30 hours in a weekend.
his maint and fuel costs went nuts.
even my seapro 21 with an F150, at 43 MPH at 5800 RPM I burn 14.8 GPH.
throttle back to 30 MPH at about 3600 RPM and my flow meter shows 6 GPH.
I can play most all day on 20 -30 gallons of fuel and get a tan .
its a 22 mile round trip from my dock to a nice waterfront resturaunt in wanchese NC.
takes 30 min each way.
ease on down to the oregon inlet bridge for an afternoon fishing and I burn about 10 gallons for the day and had a nice lunch and still spent about 60 bucks for the day.
now try to take 4 people out to dinner and a movie for that.
the movie lasted roughly 1.5 hours and ya sat in the dark and did not even talk much less say a sea turtle or dolphins or crabs swimming by or even tried a bit of clamming in the shallows.
all for under 60 bucks.

 

[David Greer]

Re: Carb Cleaning Question

on a related note: do you all recommend running the gas out of the motor if it isn't going to be used for a week or so? Month? I have just bought a used 150 Yam 2 stroke (carbs) and I am doing this with smaller engines to avoid ethanol poisoning.

 

[rodbolt]

Re: Carb Cleaning Question

I dont really reccomend running the gas out cause ya simply cannot.
that last 1/4 inch in the bowl will varnish up and clog the jets.
however almost all yamaha carbs actually have a drain.
some dont on the V models but on those simply crack open the 12mm hex plug and drain from there.

 

[Mas]

Re: Carb Cleaning Question

I dont really reccomend running the gas out cause ya simply cannot.
that last 1/4 inch in the bowl will varnish up and clog the jets.
however almost all yamaha carbs actually have a drain.
some dont on the V models but on those simply crack open the 12mm hex plug and drain from there.

Plus, with multiple carb motors, one carb will run dry while the other cylinders will pull the dry one along...mind you without any lube!

Just use a fuel stabilizers and keep your bowls full. Or better yet, use your boat often!

MAS