1957 35 Johnson (carb adjustment)

[Roberthill]

Adjusted carb to run wide open but when it's on slow running have to adjust high and low jets about half a turn richer and when running slow have to adjust jets half a turn leaner . Can someone please point me into what to check for this?

 

[racerone]

Set high speed first.-------Then bring to idle and adjust low speed mixture.-----If you have to fiddle as you suggest your carburetor needs attention.

 

[Roberthill]

Set high speed first.-------Then bring to idle and adjust low speed mixture.-----If you have to fiddle as you suggest your carburetor needs attention.

Thank you , will do this on my next trip .

 

[racerone]

All the fuel including low speed mixture goes through the high speed jet.----If you have to fiddle you need to inspect carburetor / adjustment procedure.-----Or perhaps there are other motor issues.-----What other trouble shooting has been done ?----Compression test values.----Compression values with relief disconnected are ??

 

[oldboat1]

If the h.s. jet is cleared, still need to take off the aluminum compression fitting on top to access idle passages. Best to open up the carb and soak all metal in brake or carb cleaner, then clean every opening with soft wire. Finish with carb spray using the plastic nozzle.

Like all engine adjustments and procedures, one is a complement to the others.

 

[Roberthill]

If the h.s. jet is cleared, still need to take off the aluminum compression fitting on top to access idle passages. Best to open up the carb and soak all metal in brake or carb cleaner, then clean every opening with soft wire. Finish with carb spray using the plastic nozzle.

Like all engine adjustments and procedures, one is a complement to the others.

I'm lost on "take off aluminum compression fitting to access idle passages" can you help me on this? Thanks .

 

[racerone]

A round disc on top of carburetor.------Removed to allow inspection of wee holes.------New disc is installed and hit to make it expand and stay in place.

 

[Crosbyman]

see picture below....

drill a small hole NOT TO DEEP to damage the carb....
take a pic or nail and pop it out
clean all holes 2-3 and needle exit on the side ...you should see neeedle point so unscrew it out to clean and blast the top LS circuit
reinstall a new cap
punch the center with a square head screwdriver or flat punch just enough to expand it
seal the rim with nail polish ..any colour

voilà... you are done l

 

[oldboat1]

^^Good description! Initial settings are 1 1/2 open (c.clockwise) for the l.s. needle from lightly closed. Initial h.s. setting is about half to 3/4 turn open. Adjustments are small in a clean carb (increments of 1/8 turn). Tighten the gland nuts to keep the needles in place after tuned in. Should be loose enough that you can make adjustments, but not so loose that they vibrate out and lose their settings. Each needle takes a couple of cork washers.

Final h.s. needle setting is done with the engine pushing the boat at WOT or close. After final adjustment to the h.s. setting. Set the l.s. needle again (engine warmed up and in gear). Should be about 650 rpm -- should shift into gear smoothly without jerking, and without stalling.

 

[Roberthill]

Took boat fishing , running wide open , ran good , but blew the head gasket top of top cylinder , removed spark plug and came in on one cylinder . Looking at a small (3/16") gap . Trying to find a aluminum welder , going to try repairing . Guess that was probably root of my problems.
Thanks everyone for their help. Never knew that could be taken off top of carburetor.

 

[Crosbyman]

?? did you just blow just the gasket ??? what is the welding for ???

post a picture of 3/16 gap ??? if available

 

[Roberthill]

?? did you just blow just the gasket ??? what is the welding for ???

post a picture of 3/16 gap ??? if available

Gap is at top of cylinder wall. Tried posting picture but didn't have any success.

 

[Roberthill]

Here is picture . Finally got it done.

 

[Crosbyman]

no expert on welding .. maybe you can try to fix it with some heat resistant epoxy or JB weld like products . prep it glue it shape it ... let it harden 24 hrs

J-B Weld 37901 ExtremeHeat High Temperature Resistant Metallic Paste - 3 oz, Sealants - Amazon Canada

J-B Weld 37901 ExtremeHeat High Temperature Resistant Metallic Paste - 3 oz in Sealants.

www.amazon.ca

 

[Roberthill]

The one problem with epoxy is that the head gasket would be putting pressure on it . Might work for a couple of trips but heat and pressure would take its toll . MPE(my past experience).

 

[Crosbyman]

I agree 100% yet this extreme heat version looks promissing...I would try it but not my engine.

could welding cause issues ...doesn'T look like a big job for an exoerienced aluminum welder

 

[racerone]

Is the gauge in fact aluminum or the cast iron sleeve.-----If aluminum then a product called ----LUMIWELD-----Might be used for the repair.

 

[Roberthill]

Is the gauge in fact aluminum or the cast iron sleeve.-----If aluminum then a product called ----LUMIWELD-----Might be used for the repair.

Think I am going to try this . Having a hard time finding a welder . Harbor Freight carries this. THANKS

 

[Crosbyman]

grind to bare metal heat the part not the rod

see utubes

 

[oldboat1]

Don't mean to be a downer, but particularly if you like to run your outboards hard, you might be on the lookout for a replacement l.u. There is a lot of corrosion there -- looks like salt water corrosion -- but whatever the cause I would guess the aluminum is pretty dicey. In the meantime, I would clean up what you have and fill the gap with Marine Tex -- the stuff that is supposed to be OK for engine blocks. Then refinish the mating surface of the head (piece of glass and wet/dry paper) to help alleviate warping. Then torque to specs, and retorque after running. If you have another unit ready to go, the current one will probably outlast you. It's a rule....