Johnson 150 v6 leaking gas at idle

[rich_benson]

I have checked a few videos online, so appears to be something the pump, lines, carbs, or vapor separator. Also, changed the lower unit and found grey oil (so water in it). I have changed that lower unit oil out, and fingers crossed that it wont be gray again. If it is - would love advice on which seals to replace. Rather have some advice from an expert or owner that has spend time with this particular engine. Thanks in advance.

 

[racerone]

So is it a 1977 model or a 2005 model ?

 

[Chris1956]

Gearcase is supposed to be sealed, so leaking carbs should have no effect. You likely have two issues. Plastic carb bowls warp and leak. Driveshaft, prop shaft and shift shaft seals can leak.

 

[jimmbo]

You should get the Gearcase Pressure-Vacuum tested

 

[rich_benson]

So is it a 1977 model or a 2005 model ?

My apologies - year 1993 Johnson 150 v6

 

[rich_benson]

Gearcase is supposed to be sealed, so leaking carbs should have no effect. You likely have two issues. Plastic carb bowls warp and leak. Driveshaft, prop shaft and shift shaft seals can leak.

I replaced all line fuel fittings (was zip ties) with stainless hose clamps. Snugged carb bolts. Still leaking from side of carb - warped is the plastic cover and brown gasket.

Second issue of lower unit - thank you forgot about prop seals etc. Its been 10 years since my last johnson and boat. Now I am remember as you all remind me. Think I replaced prop seals on a johnson 50 1996 with leaking lower unit.

But first things first - fuel leak!

Appreciate the support all - it means a lot for people to take time to help

I don not have the money for the professional job, so was thinking RVT or other gas immune gasket solvent. Please lmk thoughts on a coating around the suspected leaking area. Engine runs great, but a bad leak esp at idle. Dang v6 (6 carbs...).

 

[racerone]

Do not use RTV any where on a fuel system !!---------Clean carburetors / inspect float valves.------Install a seal kit for the lower unit.----Much cheaper than gears and shafts.

 

[rich_benson]

Do not use RTV any where on a fuel system !!---------Clean carburetors / inspect float valves.------Install a seal kit for the lower unit.----Much cheaper than gears and shafts.

Yes it really does sound like a BAD idea. Carbs are warped, does the rebuild kit come with the plastic sides and gasket. Would you mind pointing me to part # or link?

This caught my "fix it quick" eye "Permatex MotoSeal 1 Ultimate Gasket Maker"

For two and four cycle engines. Solvent-based bond fully seals within 20 minutes. Forms a tough flexible bond that is highly effective on irregular and uneven joint surfaces. Resists gasoline and 2-stroke oil mixtures. Withstands temperatures 350 Deg. F (177 Deg. C) continuous, 400 Deg. F (204 Deg. C) intermittent.

Product Features:

• Ideal for use on frequently disassembled engines, as well as two and four cylinder engines
• Fully seals within 20 minutes
• Forms a tough, flexible bond that is highly effective on irregular and uneven joint surfaces
• Withstands temperatures to 350 Deg. F continuous, 400 Deg. F
• Resists gasoline and other damaging fluids
• Temperature Range: up to 350 Deg. F (177 Deg. C) continuous, 400 Deg. F (204 Deg. C) intermittent

 

[Chris1956]

If carb bowls are warped, they need to be replaced. Some try to sand them flat...not sure about that as fuel pickup tube may then be too long.

Do a search on carb bowls. Perhaps you can find reasonable cost replacements. Usually high speed jets must be swapped to new bowls.

Pressure test gearcase. A gear lube pump fitting and hand pump with soapy water will do it. The driveshaft and shiftshaft seals are easier to change than the propshaft seal.

 

[racerone]

??----Just 2 bolts on that gearcase to remove the propshaft bearing carrier.------Easy in my opinion.

 

[Chris1956]

Sure, 2 bolts and a puller, some heat and some luck to pull the bearing carrier. Easy stuff.. not, try the other seals first...

 

[rich_benson]

Thanks for all the replies - found some leaking carbs and picked up gasket kits (to arrive today).

Anyone know the Johnson 150 V6 carburetor bolt torque specs?

 

[ct1762@gmail.com]

One thing to note: the recirculation lines that feed top and center crank bearings BEHIND the starter can crack and fall off/leak. i always drop the starter (leads still connected) and check to make sure they are secure and rubbery. if one or both fall off, it will run like crap and not lube the crank bearings.

 

[rich_benson]

One thing to note: the recirculation lines that feed top and center crank bearings BEHIND the starter can crack and fall off/leak. i always drop the starter (leads still connected) and check to make sure they are secure and rubbery. if one or both fall off, it will run like crap and not lube the crank bearings.

But what are the carb bolt torque specs on Johnson 150 v6 1993?

 

[racerone]

Screws for the carburetor bowl are 10 inch-lbs .-----Other 1/4" screws are 80 inch-lbs.----Then 5/16" screws are 120 inch-lbs.

 

[rich_benson]

Screws for the carburetor bowl are 10 inch-lbs .-----Other 1/4" screws are 80 inch-lbs.----Then 5/16" screws are 120 inch-lbs.

Thank you