View Full Version : Info needed before rebuild started
Brumbelowcr
05-04-2016, 09:23 AM
I have a 2000 model Johnson 50 2 cyl. The VRO died on me and fried the number 2 cylinder. #1 has 125 psi #2 has 80 psi compression. It died on me and I used the primer build to check the pump. It ran really rough. So instead of looking for a used motor, I'm going to rebuild this one. I'm going to replace all of the ignition components, rebuild the carbs, replace the vro pump with a standard fuel pump an premix, and freshen the motor. The block will be sent off to be bored and honed, decked to true the mating surface, new Pistons, bearings, gaskets and seals, head will be tried flat, and new reed valves. So basically I will have a brand new engine that should last a long time. My concerns if someone can give some pointers:
What bearings are press for if any
what to use as assembly lube
initial timing set up so it will run when first cranked
initial carb setting and final tuning
I have the service manual but I'm sure there will be more questions as I go.
racer
05-04-2016, 10:25 AM
First do you have photos of the cylinder? Generally when the VRO is the cause it will hurt both cylinders as oil is mixed into fuel before it reaches the carbs. You should not need a press and factory bearings. I like to use 2 stroke oil for assembly. Leave timing stop as it is now and you will be close. Don't know the carb setting off hand but it will be in the book.
Make sure it is clean prior to assembly.
Brumbelowcr
05-04-2016, 10:53 AM
First do you have photos of the cylinder? Generally when the VRO is the cause it will hurt both cylinders as oil is mixed into fuel before it reaches the carbs. You should not need a press and factory bearings. I like to use 2 stroke oil for assembly. Leave timing stop as it is now and you will be close. Don't know the carb setting off hand but it will be in the book.
Make sure it is clean prior to assembly.
No pics yet. I'm still in the research phase. My question about bearings was, are any of them press fit. Fuel bubbles coming from the pump. No oil mixed in after a pint or so was pumped into a glass jar to observe it.
racer
05-04-2016, 01:12 PM
Only the lower main is pressed on but I find better to heat and drop on. If you were squezing the primer bulb to check oil you will not get any, you need to do the running pulse test with the clear hose.
Brumbelowcr
05-04-2016, 01:17 PM
Only the lower main is pressed on but I find better to heat and drop on. If you were squezing the primer bulb to check oil you will not get any, you need to do the running pulse test with the clear hose.
Primer bulb check was to see if the fuel pump was bad when while I was on the lake. Did the pulse test to check the oil.
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