carb problems

[shelikesit]

2 barrel rochester id imagine.......it's on a 1993 4.3 Mercruiser.

Im not sure if a lump of corrosion freed itself in a gas line somewhere and went for the carburetor or what happened here.

Anyhow, I took the filter off at the carb and it had a clod of rust/white crud in a lump. I took all the fuel out of the tank for the second time in 3 months and there was a small amount of gel in it but nothing like what was in the filter.

OK, now, everything is new, water/sep filter, filter at carb, and an inline filter before the water/separator. They were all less than 3 months old.

Here's the problem............ when I turned it over, gas was coming out of the angled hole at the top of the carburetor. Just a pouring out like someone holding a beerball tap open over a cup.

Does this sound like a total rebuild on the carb? a new friggin carburetor? take the top off and see whats there deal, or sell the friggin thing cause im tired of unforseen crud coming from nowhere and costing me more time off the water.

Can I blow air into that angled hole or no way?

thanks.

 

[Coors]

Re: carb problems

your float/ needle and seat has trash, flooding you; rebuild carb

 

[shelikesit]

Re: carb problems

i have the mercruiser manual and the time, i would have to buy the increment tool for the float. it seems as though this is going to be a common thing since my last 4.3 had to have this done also.

is it something that if i took the time and followed the mercruiser manual i can take this thing apart and put it back together again?

my other option is buying another carb, having this one rebuilt, and have a spare, so when this happens again, i'll always have a carb handy. but if it something to learn, can it be done with a kit and the manual?

whats a merc shop usually charge for a rebuild? i had a mechanic do my last one, i payed him $50 and supplied the parts and it worked fine til i sold the vessel.

thanks

 

[Limited-Time]

Re: carb problems

.................is it something that if i took the time and followed the mercruiser manual i can take this thing apart and put it back together again?

Yes, but there is more to rebuilding a carb than replacing parts. You need to make sure all the passages are open and clear, and all of the needle seat/sealing surfaces are In tacked.

 

[shelikesit]

Re: carb problems

ok, thats a start.

i read alot about cleaning with compressed air. how much air, i keep my shop tank at 100#'s. whats the normal to clean parts with, half that?

your answer was better than a no, let them do it.

thank you.

 

[Limited-Time]

Re: carb problems

The best way I've found is to soak the disassembled components in carb cleaner to loosen any varnish formed in the passages. Then I use aerosol cans of carb cleaner with the extension tube and force cleaner through the passages. Then I use compressed air to blow out the the remaining carb cleaner. 75 psi generally does the trick.

 

[shelikesit]

Re: carb problems

ok thanks again, im reading the soaking is only for a couple hours, or do you do this longer. i'll read that manual too many times to mention before i get into this.

the tool that measures the float drop, is it commonly found in an auto parts store? or should i go ahead and get the merc tool the manual has a part number for?

im finding the rebuild kit for this carb all over the place online.

thanks for your help............ the cause of most of this mess was a broken anti-siphon vent on the back of the boat. after watching forum for a year on and off, its finally sinking in..................its senseless to fix a problem without finding the cause. greenhorns tend overlook such things......... and im guilty as sin............... the school of hard knocks..... the school that has no diploma as bondo stated.

 

[Gary H NC]

Re: carb problems

The float measuring tool comes in the rebuild kit along with the instruction and a list measurments for each engine application.Take a couple photos of the carb so you have something to go by when you put it back together..If it a 2bbl it should be pretty simple,the 4bbls have more linkages and adjustments..

 

[uaw9fan]

Re: carb problems

For one thing your carburetor is not a rochester, it's a Mercarb. Rochester's have two idle mix screws whereas a Mercarb has only one. Yes , you can overhaul it yourself.You will need to pick up a repair kit from a dealer. The repair kit will have instructions in it and a paper measuring device for float level and float drop.Personally i don't put any marine carbs into carb dip.You will do nothing but strip the paint and then have paint clogging up your very small passages. I prefer to use the carb spray as previously stated and then air out every passage.
Good luck

 

[bjcsc]

Re: carb problems

When I rebuild carbs, I do it just like Limited-Time posted (maybe it's a South Carolina thing ). I have never had any paint even soften, but then I guess it would depend on the solvent chosen for soaking. I use the regular carb. dip that comes from auto parts stores in a #10 can with the basket inside. The best soak is an overnight one.

 

[shelikesit]

Re: carb problems

thanks to all of you, from the bottom of my boat to the top of the helm........

i have to go to work in a minute, i caught one of my friends on his way to work. he knows me and my shop and told me it was time to learn the project. i have the tools, room, time and manual.

i've believed in this Merc manual ever since I put the money down for it. step by step, i'll be in class tonight after i get off the day job.

ya'll have a great saturday, your keeping me level headed and away from the pickax.

thanks.

 

[shelikesit]

Re: carb problems

finally got the time to relax and do this project. had to have the time or i wasnt going to mess with it, and im probably not finished

i took the carb apart and as soon as i seen the accelerator pump i knew i had the wrong rebuild kit. but the bowl, you could of made new england salt potatos from the grains in there. but it was still goo and not completely adhered to the bowl. you couldnt see the main jet on the bottom.

plus, since the air horn screws seemed like this thing just went through an overhaul. i bought it in spetember and ran it for 3 months, it came out of michigan fresh water and now in nice saltly stuff. it was a well taken care of boat.

long story short, i had to clean everything that was there and evidently did a decent job. i put it back on the boat and it fired up after a couple key turns. not bad for never seeing the inside of a carb before.

now get this, the needle was way bent and i never touched it before, never ever, i figured something was wrong when i followed the manual to turn it in first to see what it read. it was 3/4 of a turn. took it out bent as hell. put it back in at 3/4 of a turn and it worked....

i couldn't open this rebuild kit with a new one in it, it would of cost me 65 bux. i'll get a new one tomorrow, in the mean time the boats running and im going to bed.

about 2.5 hours, a mercruiser manual and some mellow music and it seems good for now, will know more tomorrow.

now i have to find the rebuild kit per the carb number - 9565A-6

what a great day to own a boat............. thanks ya'll, for everything. the boat ran like a bat out of hell to get home in before i screwed everything up from being negligent, i hope it will again................ everything is clean, from the tank corners to the carb.