Need to Verify items listed for replacement on 1990 Johnson 90 HP VRO outboard.

[havoc_squad]

Just acquired an aluminum fish & ski boat in good condition for a good price, knowing certain important items need to be replaced on the 1990 Johnson 90 HP VRO outboard. Model #: VJ90TLASB

It came with a service facility inspection report invoice from a local service shop that has a good reputation around here, so I know what I'm in for/fixing.

Engine appears overall well kept and not abused. The engine heads look nice and no overheat discoloration. No corrosion anywhere and the wiring is good in condition.

It was a boat that sat unused for a good while (probably about 3'ish years) inherited by the owner very recently, which did not really want to use.



First off, per inspection report the compression is good and good spark. Lower unit shifts properly. They were able to get it running for the limited time necessary to inspect and check.

The first question is, where is the best location to be able to buy the FACTORY/OEM service manual for this outboard? A digital copy is preferred. Also, which printed year of the factory service manual should I try to get? (I think there is a factory one that covers the entire range of years of that outboard series).

I've seen a CD/DVD for sale that has all makes and models compiled together for Johnson/Evinrude, but I suspect those may be the Clymer/Seloc manuals, which I want to strongly avoid. If you have any data on something like this that is comprehensive of FACTORY/OEM manuals that does not cost a ridiculous amount of money, let me know.



The items that need replacing and questions regarding them:

1. VRO pump/assembly is leaking per the report, very likely the fuel diaphragm. Is buying the OEM VRO pump rebuild kit a safe/reliable decision for just fixing the fuel pump of it? (I plan to disable VRO and run pre-mix only)

Does there exist an OEM part number for the fuel pump that deletes the VRO on this model number? I've seen an OEM part number pop up but I cannot verify that it is indeed the right part.

If there does not exist an OEM VRO deletion pump kit, can you recommend a good product for capping the oil injection port/line off. Preferably one that fits over the fitting at the VRO, instead of capping the oil injection hose.

2. How necessary is it to replace the carb bowl assembly on these motors? It was recommended in the inspection report I think because it is plastic.

I found documentation that mentioned the intermediate orfices have to be replaced with the aluminum bowl assembly. Other than paying attention to the part # on the pre-existing ones and cross referencing using the service manual, is there anything else I should know?

3. Any special notes or concerns (besides getting the correct one for the 88/90HP) involving the carb jets, carb rebuild kit, or carb float, etc.? Just asking so I know and can order it right in one attempt.

4. Replace any suspect hoses on the outboard and replace the fuel filter on the outboard motor. The inspection report on the service manual did not say which fuel hoses were deteriorating, so I am going to assume both the lines inside the outboard and the line going to the permanent fuel tank need to be replaced. Very possibly Ethanol fuel deterioration of the inner part of the hose, as the outer of the hoses on the outboard looked good.

5. Drain and replace gas. Any recommended products to use for cleaning the inside of an aluminum gas tank? I have access where I can pull it out if needed.

6. Would it be prudent to buy a poppet valve and thermostat to go along with the water pump impeller kit? (I am buying the full version of the impeller kit, including the housing to be safe).

7. Will do the normal stuff: Replace spark plugs & gap, inspect lower unit lube, pressure tester and verify the lower unit seals per the PSI in the service manual, & replace lube.



Is there anything not listed above that I haven't thought of that needs to be done?

Thanks.

 

[havoc_squad]

No replies on any of this, seems a bit odd given how long it's been created. You'd think there'd be enough marine techs/master techs that regularly service OMC/BRP outboards to at least give an educated guess or opinion on one or more of the items.

Should we blame/accuse Labor Day in the US being the main culprit for the shortage of replies? Everyone's on vacation.

 

[Joe Reeves]

The problem is that you're asking for a complete diagnoses of that engine which is impossible without actually being there.

If the VRO is faulty which is what you insinuate, it will either need rebuilding or replacing.

A factory manual, either parts or service, if not available on this site, would need to be ordered through a dealership or straight from the factory (Bombardier).

Other than taking a compression and spark test, both with "all" the spark plugs removed... installing new spark plugs, a water pump impeller at a minimum, and the gear-lube... whatever else that needs to be done depends on how the engine runs.

Use what is called "HiVis 90w" gearlube... available just about anywhere including Wal*Mart. It'll state HiVis right on the container.

Sitting that long... The carburetors are no doubt fouled, but you might try it first... you may be lucky.

VJ90TLASB <--- That model number corresponds with nothing... Check to see if it is actually J90TLESB..... ?

 

[racerone]

The first sentence says that you " know certain items need to be replaced "-----Even a motor in nice " cosmetic condition " can be junk.----Up to you to do the trouble shooting.-----I can not see / feel / hear your motor.

 

[havoc_squad]

The problem is that you're asking for a complete diagnoses of that engine which is impossible without actually being there.

I understand and appreciate the replies, the purpose for my questions was to get answers based on the data given that would help me avoid needless re-work or common mistakes on this outboard model based on the printed inspection report of the service facility.

I am aware that there is no substitute for verifying/diagnosing these items and will be doing the legwork.

I've previously owned two mercruiser sterndrive bowriders and have done some work myself (verify ignition timing, diagnose fuel pump pressure issue, lower unit impeller & lube, etc.) using OEM service manual.

So, I'm trying to avoid being a "Part Changer" doing shotgun diagnosing that wastes money and time on this outboard.

I'll refer to my VRO pump question, I wanted to know if buying the rebuild kit if the VRO pump was in good enough condition per service manual was a wise decision or not for the fuel pump only of the VRO since I plan to convert it to pre-mix only.

I don't know the percentage of success or failure on using a rebuild kit. No point paying $100 on rebuild kit and having to buy the entire VRO pump again.

Regarding the carbs, there was no doubt or question whether to rebuild them, it's 100% certain. The item that concerned me was the recommendation to replace the plastic carb bowl, I wanted to know the "why". If you know why, you understand the underlying issue and how it affects other items on the engine. Do they crack, warp easily, or does the jets in them get stuck, etc?

Spark plugs, impeller kit, lower unit lube are standard items I know how to deal with and won't go into detail for those things on this topic thread.

VJ90TLASB That model number corresponds with nothing... Check to see if it is actually J90TLESB ?

That is a valid Johnson outboard model, it is shown on the OEM BRP/Evinrude parts lookup website and other online competitor marine parts retailers.

Because of the forum links I can't hotlink to show them, but it is listed.

 

[havoc_squad]

website/brower issues, accidental double post.

 

[Joe Reeves]

That model number VJ90TLASB... I took a close look at my actual 1990 90hp parts book which also lists the other V4 models and did find the J90TLASB listed there but without the "V". If a "B" was listed at the beginning, I'd think "Mfg in Belgium"... but "V"?... Don't have a clue.

The VRO thing... since you intend to go to premix eventually anyway, why not simply convert over to the small type fuel pump that's used on the 88hp models, part #433387.

The service manual, regardless of price (it is what it is),,, obtain the factory manual... one that is specifically for your model engine alone. Having one that includes other models is nerve wracking, error creating.... and a total waste of money unless one owns all those other models in the first place.

Using a plate of glass with a sheet of 440 wet/dry paper laid on it, make a figure "8" motion on the wet paper with the plastic carburetor float chambers a couple times. If "all" of the float chamber surface is affected, they're as good as if they just came from the factory and would not need replacing.

I wouldn't bother replacing a poppet valve unless it's been affected (melted) by heat, but replacing the thermostats this time with the water pump is a good idea.

Good luck with your engine.