1975 Johnson 115 v4 won’t idle

[tylerjames5787]

Have a 1975 Johnson 115 that will not idle. I can keep it running if I hold the throttle but I’ve cleaned the carbs part number is 319671 supposedly there are not adjustable but I’ve cleaned them 3 different times the only thing I haven’t done is removed the Welch plugs because I haven’t ordered any extras. Could that possibly be my issue, all 4 cylinders have spark. I’ve done all I know to do thanks

 

[racerone]

Step #1 is always a compression test.-----Post actual values for each cylinder.

 

[tylerjames5787]

1,2,3 are 90 psi, and 4 cylinder is 89

 

[racerone]

You have a cheap gauge or a motor that needs some ( a lot ) of work.-----Remove a few bypass covers ( 6 bolts each ) and look at pistons / rings.

 

[tylerjames5787]

It is a cheap harbor freight gauge but there all close together and I checked my other boat motor which runs great and there all reading 105psi

 

[tylerjames5787]

 

[tylerjames5787]

Is this the caps your talking about removing

 

[racerone]

Correct.---Might need some new gaskets for a few $$ to learn lots.

 

[tylerjames5787]

Well I don’t know what I’m looking for I took the covers off rolled the motor by hand after taking the spark plugs out and I don’t see anything wrong with piston or rings I put the covers back on and still have the same 90 compression so I think the gaskets are good even after taking them off

 

[tylerjames5787]

What’s the compression suppose to be on this motor

 

[racerone]

About 120 PSI or more.----Those gaskets have nothing to do with compression in the cylinders.----Does spark jump a gap of 7/16" on all 4 leads using a test device?

 

[jimmbo]

Take a small Blade Screw Driver, place the tip along each Ring, and see if it has any Spring to it. Oh, you already put the Covers back on.

And yes to the Welsh Plug Question, a lot of Gum and Varnish can be under them and all the Carb Cleaner in the world won't dissolve it.
However before tearing the Carb apart again, do what racer suggested.
When you R&Red the Carbs, you also needed to do a Check of the Sync between the Carbs, and of the Carbs Sync to the Spark Advance

 

[tylerjames5787]

Ok may be getting somewhere only one cylinder is jumping a 7/16 gap

 

[tylerjames5787]

Ok may be getting somewhere only one cylinder is jumping a 7/16 gap

All these coils are new. And they all have spark but only one jumps a big gap

 

[racerone]

Did you inspect the reed valves when carburetors were off the motor?----- Did you remove / clean the high speed jets in the carburetors ?----They are screwed into the very bottom of the float bowls.----Only 2 in each float bowl.---Brass and about 5/8" long with 1/4-20 thread.-----Called an orifice plug as well.----Do not run this motor hoping it will fix itself.-----

 

[tylerjames5787]

I didn’t check the reed valves but on the carb yes I cleaned everything. And no worries about me running it because it won’t even crank

 

[racerone]

So have the battery charged and load tested.----Inspect battery cables.----Take starter apart for cleaning / inspection / new brushes ? / ohm test on armature.