1998 50hp Johnson Rebuild First Startup Advise Needed

[Aaron Huyser]

Hi all,

I have finished rebuilding the engine. When I say rebuild I mean its been completely overhauled. I just finished getting everything back together meaning harness, lower end, shift assembly, throttle assembly, etc. I'm at the point now where it would be time for fresh gas and a first start up. Saying that is there anything special I need to do? I know I will need to run a break in cycle according to the manual which is fine but don't I need to set timing on the engine? How do I do this if I can't run the engine up into the high RPM that the manual calls for to set timing. Also I oiled all components during assembly but the powerhead sat a week or two while I rebuilt the lower end so should I add a little extra oil through the spark plug holes? Should first startup be on muffs? I know these may seem like silly questions but any advise ya'll can give for a first start up will be a huge help. I'm very mechanically inclined and have a good skill set But I would like to get the advise of others to make sure I do things to the T anything I would need to do for first startup please let me know.

Take care

 

[flyingscott]

Fuel mixed at 25-1. Timing can be set with the joe reeves method.

 

[Aaron Huyser]

can you explain further on the joe reeves method or link to it please that I've not heard of that.

how about base mixture screw on these carbs? I know the main jet is fixed but there is a low speed mixture screw from what I understand. Can I run first start up on muffs?

 

[flyingscott]

1.5 turns out should get you started. I dont like starting rebuilt motors up on muffs I would find a garbage can and use that. https://forums.iboats.com/forum/eng...ns-faq/234008-joe-reeves-wot-timing-procedure

 

[Aaron Huyser]

Sounds good I'm a bit confused on the rigging of a spark plug tester at 7/16” section of the joe reeves method can you extrapolate also since ill be cranking The engine over in non running state should I squirt a little 2 cycle oil in the cylinders?

 

[flyingscott]

You use an adjustable spark checker that you set at 7/16" air gap. You will need someone to crank it for you. I.would throw some fogging oil in the cylinders.

 

[Aaron Huyser]

Might you link me to such a spark checker? Also how do I know if i have quickstart?

 

[flyingscott]

Nearest auto parts store wil have one for around $10. Do you have the factory service manual or owners manual? That will tell you if you have quickstart.

 

[Faztbullet]

Rebuild or refresh??

 

[jimmbo]

If your engine has a working VRO system, a 50:1 mix in the tank for the first 10 hours is what the Manual would state. If the VRO is disabled/removed, then 24:1 for the first 10 hours.

 

[Aaron Huyser]

-No vro anymore so 24:1 for first 10 hrs
- i have a 1990-2001 2-70hp service manual for evinrude/johnson.
-As for rebuild or refresh let me put it this way. The original engine blew from a self destructed lower bearing i purchased a new/used top end that had been fully looked through cleaned and any parts outside spec where replaced cylinders were honed and it had new rings and pistons heres a few pics of what i purchased and assembled.

 

[Aaron Huyser]

Is this the type of adjustable spark tester id need for the timing portion?

 

[havoc_squad]

Yes, that is the spark tester to be used. The other spark plugs also need some way to be grounded.

Ignition coils don't like to be energized and have no place to dump that spark energy.

If possible, ditch the aftermarket service manual for OEM. Difference is night and day on certain critical bits of info regarding that year/model.

 

[Aaron Huyser]

Ok so:

-pull both plugs
-ground the bottom plug with a wire
-put spark plug tester in top plug wire boot and set to 7/16 inch gap and ground with clip
-proceed with Rest of joe reeves process

- is there anyway other way to know if I have quick start feature?

 

[Faztbullet]

That's a refresh......mix 50/1 add 6 oz extra oil, start on trailer in water lower unit partially submerged, start and set idle/timings/leaks/etcl, put in gear and keep a 1000RPM for 5 min. Raise in 500Rpm increments every 5 mins till you reach 3500RPM. Take off trailer and run the same till max RPM reached and your done. about 2 hrs

 

[lindy46]

1.5 turns out should get you started. I dont like starting rebuilt motors up on muffs I would find a garbage can and use that. https://forums.iboats.com/forum/eng...ns-faq/234008-joe-reeves-wot-timing-procedure

2 cylinder 2 cycle 50hp engines of this vintage have twin carbs. Initial slow speed needle setting is 3.5 turns out from lightly seated.

 

[Aaron Huyser]

So Is that mixture what i would need if i was mixing say 5 gallons 50/1 plus 6oz? Even with cylinders honed

 

[Aaron Huyser]

That's a refresh......mix 50/1 add 6 oz extra oil, start on trailer in water lower unit partially submerged, start and set idle/timings/leaks/etcl, put in gear and keep a 1000RPM for 5 min. Raise in 500Rpm increments every 5 mins till you reach 3500RPM. Take off trailer and run the same till max RPM reached and your done. about 2 hrs

-So if Im mixing 5 gallons at a time should i still mix 50:1 plus 6oz and would this be the same even if cylinders are honed?

-once off the trailer do i start back at 1000 rpm and work my way up to max rpm and hold for 5min at max rpm?

 

[Aaron Huyser]

Nearest auto parts store wil have one for around $10. Do you have the factory service manual or owners manual? That will tell you if you have quickstart.

Another question regarding the joe reeves method it pertains to this portion:

”To set the timing on that engine, have the s/plugs out, and have the throttle at full, set that timer base under the flywheel tight against the rubber stop on the end of the full spark timer advance stop screw (wire it against that stop if necessary)”

I do not have full advance stop screw my timing is adjusted my shortening or elongating the timing linkage. Please see the attached photo how would apply his method? Would I just concoct a way to make sure it has no play or movement in it while setting the timing?

I'm aware that the linkage is out of wack currently I have not done a link and sync yet.

 

[Faztbullet]

once off the trailer do i start back at 1000 rpm and work my way up to max rpm and hold for 5min at max rpm?​

Start at 3000RPM and work your way up....and use 4oz extra to 5 gallons