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1990 something Johnson 40hp won't start have spark

M

MaiTai

New member
Hello all - Just got a 1990 something Johnson 40hp which had no spark and took to mechanic to troubleshoot who replaced the stator, cdi and coil. After this it was running. Then of course when launching the boat for the first time it wouldn't start. The mechanic is out of town for a while and I have tested spark at 1/2 inch, timing is on the mark, compression in #1 is 125 and #2 is 130, water got in the fuel so replaced fuel and flushed out of the carb bowls and got new plugs. Have also tried spraying fuel mix and starter fluid in carb and piston just to see if I could get any pop. When starting am holding in key choke and can hear a click when pushing in, have also tried turning red valve in the opposite way. Any advice is greatly appreciated.
 
Hi - had checked timing with timing gun and it is on with painted mark prior owner had made on flywheel - have not removed flywheel
 
Check flywheel key !!!----Note----You can not find a sheared key with a timing light.-----Repeat----Check the flywheel key.----Costs no beer tokens.
 
How long have you owned this motor.-----Something is wrong there.----This motor should have an external thread and a nut on the end of the crankshaft !!----Looks like a mickey mouse fix there.-----Torque on the nut is 100 ft-lbs.----No idea what to torque that bolt to in order to keep the key from shearing.----Myself I would replace the crankshaft.-----And post the model # as something is amiss I think.
 
Thats not a new stator..hope mechanic didnt charge ya for a new one. Mechanic shouldn't even repaired it with the crank stub "engineered" that way
 
The mechanic broke the nut getting the flywheel off and tapped a bolt as a fix. Claims this 'fix' will hold the flywheel. Do you think the key will continue to shear because of this? The bolt was fairly tight and had loctite red in it but definitely not 100 ft-lbs. I will confirm what exactly was replaced. Any ideas on the year of the motor and where to get a repair manual? Thanks for the info.

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Cowling appears to be a 1991 model.-----I think the key will shear again !------And again.-----Not a good fix.-----The key positions the flywheel for correct timing.-----The flywheel is driven by the locking tapers.----That is why the nut is torqued on these motors !----And there is no reason for the nut to be damaged when removing the flywheel either.
 
What size bolt is now holding that flywheel on? A 1/2" grade 8 will hold 100'# but I see 2 concerns:
* Looks like he drilled the pilot hole too big. The thread cut depth looks to me to be less than 50%. Probably will strip the shallow threads out at 100#.
* Make sure when the flywheel is pressed down completely that the stub is beneath the top surface (tighten, then remove bolt to check). You need a thick cone washer if it protrudes.

Locktite red tells me he doubted it would hold.
 
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