1997 Johnson Mod: J90TSLEUA

[utfyrfytr]

Just bought a different boat with a 1997 90hp Johnson and I'm looking for a service manual for it. It appears there are a couple of different manuals, one for 60 degree motor and another for 90 degree. This is my first experience with Johnson and I'm not sure what the difference is. Another thing is I cannot find a model reference that has the S in the model number. Thanks for any information you may have.

 

[racerone]

The 2 engines are totally different.-----You need the manual for the 90 degree block.------Do a compression test and post your numbers before spending any beer tokens on this motor.----Ignore the ---S--- as it means very little.

 

[Crosbyman]

 

[utfyrfytr]

I take it from your comment that you are not a fan of this motor. What kind of compression numbers am I looking for?

 

[racerone]

Agreed the " ocean runner " models had a few key parts / hardware made with stainless.

 

[utfyrfytr]

Okay, great!! What should the compression numbers be? It's 8 degrees outside so it will probably be a few weeks before I get out to test it.

 

[racerone]

You would like to see 125 PSI.----If you have that and one cylinder at 105 there issues.----These motors all suffer from broken piston rings.

 

[airshot]

When ever I buy a used motor, the first thing I do is run a compression test ! Usually before I buy it, to know the engine isn't worn out...

 

[utfyrfytr]

I did in fact run a compression test before I bought the boat. The numbers were 100-105 over the four cylinders. I wasn't sure of what they should be but I figured with all of them being that close that it was a sign of some wear but nothing catastrophic. Was I wrong. The boat had been sitting for a year and it was a cold fall morning probably in the 20's when I did the test. If that makes any difference.

 

[Crosbyman]

lots of variables ...at this point gauge accuracy, gauge type, temperature etc... wait till you run it to redo testing. you own nowit so wait and see.

 

[airshot]

I did in fact run a compression test before I bought the boat. The numbers were 100-105 over the four cylinders. I wasn't sure of what they should be but I figured with all of them being that close that it was a sign of some wear but nothing catastrophic. Was I wrong. The boat had been sitting for a year and it was a cold fall morning probably in the 20's when I did the test. If that makes any difference.

A bit low, but depending on what else you find they might be doable. Depending on how long it has been sitting and other varibles.

 

[utfyrfytr]

I'm by no means any kind of a mechanic so... when I do the next test should I fog the cylinders prior to testing? When I did the test I removed all 4 plugs before testing. That is the correct procedure correct?

 

[Chris1956]

Gee, the OMC 90* 90HPV4 engine was made for a lot of years. I think the first one I saw was in the late 60's (crossflow version). They lasted until about 2000 (loop charged version), when replaced by the 60* V4 engine series. They were one of the best and most popular engines ever made, IMO, although the 60* V engines are better, also IMO.

 

[airshot]

I'm by no means any kind of a mechanic so... when I do the next test should I fog the cylinders prior to testing? When I did the test I removed all 4 plugs before testing. That is the correct procedure correct?

I would find a "factory" service manual for that motor, then you will have all the information that you need as well as trouble shooting tips.

 

[racerone]

Maybe remove the 4 bypass covers to inspect pistons and rings.

 

[utfyrfytr]

Looking at service manuals, which do I need? There are 90* CV, 90* LV EU 90* CV. I guess it makes a difference or there wouldn't be so many different titles.

 

[racerone]

Your motor is the 90 crossflow.-----So it is the 90*CV that you need.----LV is for a totally different LOOP charged V- 4 / 6

 

[utfyrfytr]

Okay, Thanks for all of the information. I appreciate all of the help

 

[ct1762@gmail.com]

the looper v4 60 degree was made from 1995 through OMC bankruptcy. I know BRP made the v6 through 2004 or 2007 but not sure if they did the v4 in 60 degree. 90 degree 135 v4 yes but only for a year or 2

 

[racerone]

You are not sure.