1974 Johnson 6 hp weak to no water at idle HELP

[edgarop]

i have a 6 hp 6R74 johnson that i put a head gasket, impeller and thermostat in as well as new exhaust housing gasket. The problem with it is that it doesnt shoot water out at an idle but when throttle up the water shoots well after a couple of seconds it first comes out steaming then cools down. The motor also seems to speed up by itself. any clues would be helpful thanks

 

[edgarop]

Re: 1974 Johnson 6 hp weak to no water at idle HELP

bump help

 

[restornator]

Re: 1974 Johnson 6 hp weak to no water at idle HELP

well, the thermostat restricts water flow at idle

 

[Happyfingers]

Re: 1974 Johnson 6 hp weak to no water at idle HELP

has the copper pipe seated correctly into the water pump housing ? (the little rubber thing)

meaning your flow whilst present may be restricted and only work at high revs

it takes literally 10 mins to get the thing off and have a look
just do it

 

[F_R]

Re: 1974 Johnson 6 hp weak to no water at idle HELP

Where are you running that thing? Is it on a boat in the lake, or is it in a bucket? It was designed to run on a boat.

If it is on a boat, you either have a worn water pump (housing) or you have air getting into the pump from below.

I suspect you have it in a bucket....'nuff said.

 

[edgarop]

Re: 1974 Johnson 6 hp weak to no water at idle HELP

i'm running it in a bucket with about 20 gallons of water. Its was previously overheated so i installed a new impeller, head gasket, and termostat. i sanded the head flat there was minor difference just to make sure. water tube is hooked up but didnt do a new rubber grommet. it also wants to idle rev up by itself tryig to idle.

 

[F_R]

Re: 1974 Johnson 6 hp weak to no water at idle HELP

Try it on a boat and report back if you still have trouble.

 

[Stephen_555]

Re: 1974 Johnson 6 hp weak to no water at idle HELP

Make sure that the pump housing plate you took off to replace your impeller is not upside down. Did that once before and gave me the same problem minus the rev-ing up.

 

[edgarop]

Re: 1974 Johnson 6 hp weak to no water at idle HELP

which way is right side up?

 

[F_R]

Re: 1974 Johnson 6 hp weak to no water at idle HELP

I would be surprised if it will even fit upside down on that motor. But then I've never tried it either. It will be obvious which side has the wear pattern from the impeller sliding across it.

 

[edgarop]

Re: 1974 Johnson 6 hp weak to no water at idle HELP

i pulled the lower unit last night all was in correct order. and you cant install it upside down, the bolts down line up as well as it would hit the housing. i put it back together and fired it up. I dont know what i did different but it shots water out at idle now. my other problem is it seems to only be firing on 1 cylinder i pull off the top wire and no changes at rev or idle. I grab coil wire bare hand and i feel a light shock. i pulled the spark plugs and ground them and both have spark. wants goin on?