1989 70 - orifice service bulletin?

[tedious]

Some time ago I ran across a post that referred to a service bulletin about a changing the stock orifices - I could be misremembering, but I think it was to avoid a potential lean condition. I know that the one sure way to trash the classic triple is to run lean for any period of time, so if anyone could point me in the right direction or otherwise educate me / set me straight I'd appreciate it. Thanks!

Tim

 

[tashasdaddy]

Re: 1989 70 - orifice service bulletin?

do you have evinrude or johnson?

 

[tedious]

Re: 1989 70 - orifice service bulletin?

1989 Johnson 70.

Tim

 

[Dhadley]

Re: 1989 70 - orifice service bulletin?

Make sure that when you read the bulletin that you know which carbs you have - early or late production. They look similar but the internal calibration is very different. BTW - yours is the 56 cid (newer) style. When you refer to a "classic" 3 cylinder that brings to mind the 49 cid version. Very different powerheads.

 

[tedious]

Re: 1989 70 - orifice service bulletin?

Thanks - I was aware the carbs switched over sometime during 89 - not sure which I have as it's all under the shrinkwrap at present. Do you have any pointers to or info from the bulletin itself?

I guess I'll start to call my motor "neo-classic" from now on...

Tim

 

[Dhadley]

Re: 1989 70 - orifice service bulletin?

The late production carbs have adjustable slow speed jets. There were a couple of bulletins out dealing with issues about water pump changes, overboard water outlet relocation, high speed jet changes, temp sender changes etc.

One of the things we noticed early on was that the motors that had issues with #2 cylinder all had some similiar things going on. Most motors were set up at less than 5800 rpm, some had incorrect spark plugs and some were run almost all the time in the mid range (cruise) mode. Motors that were run at wide open didn't seem to have issues.

On motors we were involved with we made all the recommended changes but some still had some repete issues. We then started to make changes to the mid range jets. (That's basically what you're running on in cruise mode) In the cruise range you're running on full spark advance and very little fuel. On those motors #2 runs the hottest. On prolonged mid rane running the heat in #2 built up enough to cause problems. If you made the same trip at wot there was enough fuel going in to control the combustion temp.

On motors that we richened up in the mid range by 2 or 3 numbers didn't seem the have repete issues.

 

[clanton]

Re: 1989 70 - orifice service bulletin?

The SB was for 1990/92 motors. Somewhere on this site are the SB number and jet sizes try the search.

 

[clanton]

Re: 1989 70 - orifice service bulletin?

If you can`t find it, keep bugging me, and i will get the SB, may take a week.

 

[seahorse5]

Re: 1989 70 - orifice service bulletin?

Some time ago I ran across a post that referred to a service bulletin about a changing the stock orifices Tim

Here are the important bulletins concerning the 60-70hp 3 bangers.

60 & 70 hp service bulletins for cooling and overheating

SB 2221 Temp sensor new sensor pn 584166, tan/blue stripe wire.

SB 2225 thermostat seat new seat pn 336416, may not need this in fresh water.

SB 2271 jet and timing kits ds

SB 2276R1 relocate tattle tale nipple to top of block.

SB 2276R1 and new pressure relief springs comes in waterpump kit pn 432955.

 

[tedious]

Re: 1989 70 - orifice service bulletin?

Thanks. Is there an online source for TSBs, or does anyone have access to them? I think I have seen the relocate telltale somewhere here on iboats.

Tim

 

[tashasdaddy]

Re: 1989 70 - orifice service bulletin?

here the procedure. http://forums.iboats.com/showthread.php?t=222677