1973 johnson 85 horse

[73whaler]

lower carbs do not seem to be getting enough fuel. took out lower carbs and blew out with throttle plate cleaner and still same. motor idles and runs and when under load i spray fuel in lower carbs the motor runs great. i didnt take out core plugs because i didnt have a kit. not sure whats under those caps. bought from older man that hasnt been out for two years but he said it ran great. hheellppp i want to go fishing. thanks

 

[wilde1j]

Re: 1973 johnson 85 horse

You can't clean a carb by sending anything through the throat. See below:

http://forums.iboats.com/showthread.php?t=244013

 

[73whaler]

Re: 1973 johnson 85 horse

i did take it apart and put back together, but my question is what is under those core plugs ? is that my problem? everything inside looked good with minimal grumice.

 

[rattlin]

Re: 1973 johnson 85 horse

What do you mean by "core" plugs? The brass screws on either the side of the bowl?

Did you inspect/clean the high speed orifices?

Also, be careful not to spray too much fuel into the throats if it's not mixed with oil.

 

[wilde1j]

Re: 1973 johnson 85 horse

Typically the core plugs need to come out, but I don't have a shop manual for your motor.

 

[73whaler]

Re: 1973 johnson 85 horse

they call them core plugs on the microfiche, the size of dimes they are inside the carb. and the two brass rods with holes in are cleaned out but i did not remove them,they looked pressed in. sounds like i should buy the kits and retry.

 

[73whaler]

Re: 1973 johnson 85 horse

could i have a broken reed thats not making enough vacum?? just a thought

 

[ezeke]

Re: 1973 johnson 85 horse

Behind the screws on the sides of the carburetor bodies (not the float bowls) are the four idle jets.

The fuel passes through those on the way to the carburetor throats where it emerges though four tiny holes in the floor of each of the four carburetor throats. If you open the choke and throttle plates and look beyond the throttle plates, you can see the holes if you look carefully.

The vacuum created by the pistons must pull fuel from the float bowls, through the idle jets and into the carburetor throats by way of those small holes, so you have to be sure that they are all open.

When you have that done, you need to assure that the choke and throttle plates are perfectly synchronized. The throttle plates need to be fully closed at idle and move together through the entire range of motion.

 

[wilde1j]

Re: 1973 johnson 85 horse

Reed failures are extremely rare (I have yet to see one where the failure wasn't caused by owner abuse).

 

[73whaler]

Re: 1973 johnson 85 horse

The problem was in the lower carb where the needles pick up fuel. The lower piece of carb had some sandy material that was crusty. Thanks for all the help i figured i better post the outcome. My 1973 whaler tashmoo must be a rare bird im having trouble finding anything to compare it to. Was curious about its value. 17 ft with a 85 johnson. The old man i bought it from bought it new for 4500 bucks in 73. Its unmolested,garage kept,and no saltwater in pennsylvannia. All the cushions are original. Cleaned the boat inside and out and it shines like brand new. Sitting on top of newer trailer. Any ideas? I could use the money....

 

[DJ]

Re: 1973 johnson 85 horse

Very rare and "odd" boat.

Post some pic's on www.continuouswave.com

Those guys will get a kick out of seeing it.

The 73 85 was a bulletproof engine.

Get two kits and remove the core plugs. The plugs come with the kits.

 

[emdsapmgr]

Re: 1973 johnson 85 horse

Likely there is some dried fuel in the internal carb passages. You have to pull the carbs completely down to really clean them out. The only good way to clean them out is to spray some aerosol carb cleaner through each passageway. Do one passage on one carb and note the exiting spray pattern. Then do the same passage on the other carb. Once they both flow the same, go on to the next passage, etc. Pull all the jets and visually check for debris before reinstalling.