1972 Johnson 65 HP 65ESL72S timing issue or?

Strong Coffee

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Jan 5, 2019
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New member at a loss with newly rebuilt 1972 65 HP Johnson. Motor starts and idles fine on muffs and in the water. Good compression on all (3) cylinders, all right around 120 +- a couple. The problem I am having is soon as I put it into gear it wants to die. If I have the start lever up a bit to increase rpms a bit, the motor will go into gear just fine and run like a champ. Timing is currently sitting at 8* at idle. Just checked timer base off and cleaned and oiled it. So that it is moving freely. All carbs were taken apart, cleaned really well and rebuilt with new carb rebuild kits.

Any help / suggestions are appreciated.
 

racerone

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Dec 28, 2013
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Do you have spark on all 3 leads that jumps a gap on a test device.----Set the gap at 3/8" ( 1 cm )------What was the reason for the rebuild ?-----Did you find and correct the cause ?
 

F_R

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Jul 7, 2006
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Set the idle speed up a bit (at the motor). Too slow in neutral, it dies when a load is applied.
 

Strong Coffee

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Jan 5, 2019
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Good spark on all but will double check again. Reason for rebuild......replaced a piston and rings about 2 years ago. Ended up blowing another piston so decided to tear it all down and put all new gaskets, pistons,, rings, etc.

Setting idle speed higher to where it won't die means it will bang into gear and that does not seem good.......
 

Joe Reeves

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Feb 24, 2002
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Strong Coffee..... Do Not speak in generalities such as "Good Spark" or compression is "Great" or right around a certain figure, that sort of thing means nothing to us. We need info that is specific such as "racerone" speaks of above.

If you need to have the idle so high that the engine SLAMS into gear when shifted, something is vastly wrong such as compression, improper ignition, synchronization, something! You need to go back and start over with the trouble shooting procedure, making sure that all is as it should be.

Start with the carburetors... the throttle linkages between the carburetors. Back the roller away so that it is not touching the metal cam. Double check those linkages so that all three throttle butterflies start to open and close at the same time. You do not want for instance... two butterflies closed and one ever so slightly open.

The distance between the vertical throttle arm and the metal cam must be exactly as per this diagram.
Click image for larger version  Name:	75_70HP SYNC LINKAGE1a.jpg Views:	2 Size:	56.2 KB ID:	10694049
Now.... align the scribe mark (adjust the roller) so that the throttle butterflies just start to open when the 1st scribe mark is dead center with the center of the roller... not before or after. This takes care of the synchronization process.

Remove all spark plugs... What is the compression psi readings of each cylinders. Top cylinder is #1.

All plugs still removed... the spark must jump a 7/16" gap with a strong blue lightning like flame... a real SNAP! Does it?

Spark plugs should be Champion QL77JC4 plugs gaped at either .030 (long life) or .040 (strong spark)

If adjusting the idle on a flushette, depending on the shaft length it should be set to:

20" shaft - 1000 rpm
25" shaft - 1200 rpm

The idle will drop to normal when in the water due to exhaust back pressure.

Let us know what you find.
 

Strong Coffee

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Jan 5, 2019
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Thanks for the replies. I may not get back with the information asked for a couple days and possibly not next weekend. Busy work schedule and family life keep the fishing and mechanicing to a minimum. I will post back soon as possible. Thanks again!!
 

Strong Coffee

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Jan 5, 2019
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I meant to type "possibly not UNTIL next weekend". Typing skills are not the greatest :facepalm:
 
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