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1971 Johnson Outboard Model 20R71S Idle problem

J

jtblas

Member
"I have an outboard Johnson mo

"I have an outboard Johnson motor that is 20 HP. This is the 20R71S. When I place the engine on idle, it starts kicking and turns off. My friend has tuned the carburetor to specifications in the manual and it still kicks when placed on idle. There is a part which appears to be a rubber roller right on the "governor." The roller moves out as you increase the acceleration. We are guessing that this roller has become wasted and takes the engine below idle. If this is the problem, I would like to have someone explain this to me if possible; if the problem is this roller, it would be great if someone would tell me the part number for that roller.like

We are looking for answers as to why this engine turns off and kiccks when placed on idel. Any suggestions are greatly appreciated.}"
 
"The kicking you are experienc

"The kicking you are experiencing is the engine running lean, from carby being set too lean on the low soeed mix screw...the rubber roller touching the advance cam too early...an air leak somewhere"
 
"thanks for the help<font size

"thanks for the help<font size=""-2""> thus far. Just to </font>summarize, are you suggesting that either :

(1) Carb running too lean
(2) roller touching advanced CAM too soon
(3) an air leak somewhere.
In the case of #1: Do you have any suggestions to alleviate this. I believe I have an incorrect gas/oil mixture which I am going to correct today.

In the case of #2: The roller touching the advanced CAM too soon: Is this the roller I made mention of earlier? I noticed this roller is a bit wasted and might need replacement. TIt is held down by a c clamp. Do you have the part numbers for the roller and c clamp so that I can add them to the list of items I mus get.

In the case of #3: What is the best way to check for this air leak? I have put in an O ring that was missing. ? on the side of the gas line. What else could be the issue? The carburetor does not have a cover and I wonder if this is the case."
 
Joe turn the low speed mixture

Joe turn the low speed mixture screw out 1 turn and see how it runs if it runs ok start turning it in untill it misses then turn it out a quarter of a turn
 
1-I replaced the thermostat on

1-I replaced the thermostat on Friday.
2-I will take a look at the low speed valve.-will need to do this after I replace the manual start spring which broke on Friday.
3- What is the best way to check temperature and what is the optimal temperature.
4-will check the roller as well. this is something I asked about recently. This roller appears to be wasted and I know it needs replacing.
 
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