Need help identifying 90HP V4 VRO model (1988 I think)

[ironring1]

Hello, all - first post!

I recently picked up a used boat that has a pair of engines. A 90HP Johnson V4 VRO and a Honda BF15A.

The Johnson needs a little TLC (mainly throttle cable adjustment, I believe, but I would like to identify the engine. The welch plug inside appears to be missing, and the plate with the serial/model number on the outside also appear to be missing (or painted over -
someone repainted the engine inside and out at some point...).

The closest that I cam come are the numbers stamped into the engine's castings. The main block has a part number stamped into it, and then a smaller "88 12" stamped in it, which makes me think that the casting was made in December 1988. That suggests to me that the engine is a 1988 or 1989, but I hit a dead end there. Some other sleuthing tells me that there are three basic 90HP models Johnson made these years: 90MLyy, 90TLyy, 90TXyy, where yy is the year code. I don't care exactly about the year, but I would like to know enough to locate the correct manuals.

Any help would be greatly appreciated!

 

[bikermikeyblack]

I have a GT 100 with the same problem don’t know the model. I read somewhere a DEALER could look up the serial number but as we have no dealers anymore I don’t know if that’s a possibility I’m guessing mine to be a 92-93
I’m not sure but I think those numbers you are looking at are casting numbers
Good luck

 

[ironring1]

I’m not sure but I think those numbers you are looking at are casting numbers
Good luck

I agree that they are casting numbers, but there actually are several numbers there. What I am looking at (sorry for the blurry photo) are the two smaller 2-digit numbers on the casting, roughly lined up with the "vw-1" on the hose above them. "12", then a space, then "88". If you look to the left of the "12", you can also see a "7" in the same font & size. It is common place for castings to be stamped with date of manufacture for quality control, so this casting - not necessarily the engine - was likely made either on July 7, 1988 or Dec. 7, 1988. The casting itself appears to be numbered "186691" or something similar.

 

[flyingscott]

Look for a silver disc on the block itself.

 

[Faztbullet]

Needs more TLC than just cable issue...start with compression test

 

[ironring1]

Needs more TLC than just cable issue...start with compression test

It ran just fine, but I could see the throttle was only being moved about 25% with the control fully forward. I agree it isn't pretty. I want to slowly clean it up, but for that I would like to have the proper service manual.

 

[ironring1]

Look for a silver disc on the block itself.

This is the welch plug I said was missing