Upgrading Johnson qd-14 10 hp ,want info on cranks and parts

[Robert Andrews]

Hello,My name is robert-Robworks612,i am rebuilding a 1953 qd-14.I have heard you can up grade rod and perhaps pistons to be able to use bearings in wrist pins and not sure about if you can get caged crank bearings.Do i have to have a different crank to use different rods? And what crank if i do and what rods can i go with.Years and part numbers would be greatly appreciated.I recieved a set of pistons yrs.ago when i bought powerhead and other parts for this motor.I have rods and pistons and i looked up every year using part number on rod with no luck at outboared marine.The number on rods are 307850 and piston 307851.I miced them inside crank end and miced pistons.they are same size as original only they have wrist pin bearings.I have not tried bolting anything up but the rods are little beffier but all else is same but with wrist pin bearings.Can someone pls. help me get started on this project.its my 90 year old fathers and i so want to have him on lake before winter.So sincerely,Robert.SORRY SO LONG.IM new and green

robworks39

[frankr]

For the upgrade, you need the following parts for each cylinder:

2- 302577 retaining rings
1- 307849 wrist pin
1- 378251 wrist pin bearing
1- 378285 piston
1- 378330 connecting rod

These parts update the pistons & pins to the 1962-63 style. No need to replace crankshaft or crank bearings

Don’t pay any attention to the casting numbers on the parts.

[Robert Andrews]

so if i got a 62-63 powerhead that was good these parts wld work?of coarse new rings etc.thank you so very much.Is it ok to ad you as a friend?thank you so so much.,if i post incorrectly please tell me.im a greenhorn on this site but a half decent mech.sounds like you know alot .again thank you.rob

robworks39

[frankr]

Welcome. Yes, the ’62-63 parts mentioned above will fit into older models.

[Robert Andrews]

thank you frankr,your awesome!

robworks39

[Mumbles]

’61 – ’63 are the magic years for motors with the upgraded rods and pistons with needle bearings on the pin. Here’s some photos for comparison.

[Author]

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