Johnson '86 48SPL to '88 60 swap questions.

[JB]

Howdy, all.

I am repowering RED SKY from one Johnny to another. Three questions:

1. I have found a 1989 Service Manual for the 60 and 70hp triples on eBay. It seems to me that I recall that the triple loopers were bored out and redesigned in 1988. Would that '89 manual work for my 1988 60?

2. The tach that I have for the 48SPL had a three-wire cable that plugged into the old control (no PT&T switch). On casual examination there doesn't appear to be a similar socket on the controller for the 60 (includes PT&T switch). My SELOC manual wiring diagram offers no help. Will the OEM manual show me how and where to connect it? I do know that I will have to reset the switch on the back for 3 cylinders.

3. The 60 is rated at 5,000rpm and the 70 at 5,700. Is it possible that the difference is simply ignition timing and max advance, or is it more likely involving things like carb venturis, reeds, port timing and the like? I don't want to make a hotrod out of it, but if swapping a part or three would let me rev her to 5,700 or even 6,000 I think that would be nice.

Thanks for your guidance.

 

[rickdb1boat]

Re: Johnson '86 48SPL to '88 60 swap questions.

The Manual will be the same. The Tach. setting should also remain the same (6 pulse). I would be suprised if the new controller did not have the tach plug. If not, it will be the gray wire from the terminal board you're after. Just continue it on to the gauge if you are using the same harness. Don't know about hot rodding it up, but I bet it would have no problem running a 5800 RPM's......Should be an easy and worthwhile swap JB....

 

[Frank Acampora]

Re: Johnson '86 48SPL to '88 60 swap questions.

I worked on one of those triple looper 60s and the timing was only 18 deg at wot. Look up the timing on the 70. If it is greater, then there is part of your increase. There was also a small vent hole in the cylinder wall about 1/2 inch above the exhaust ports. I never found out what it was there for. Maybe someone else out there knows.
BTW. Manual recommends a specific method to time it I think because of compliance in the linkage.

 

[JB]

Re: Johnson '86 48SPL to '88 60 swap questions.

Thanks, Gents.

I will bid on the Manual and wait for its wisdom on the other items.