1991 Johnson 200hp Air Silencer help needed...

[fish2day]

Re: 1991 Johnson 200hp Air Silencer help needed...

Yes, The metal plate on the starboard side has 4 screws, not 2.

 

[fish2day]

Re: 1991 Johnson 200hp Air Silencer help needed...

Where do I go from here? Can I put the correct size jets in these carbs and run them? Or do I have to change the complete carb assembly?

 

[dazk14]

Re: 1991 Johnson 200hp Air Silencer help needed...

It's quite possible, 1992 model year carbs found their way onto a 1991 straight from the factory. The mains work out the idle and mids are different.

Let's get back to some clear history of this motor and get some facts straight.

You indicated the motor had sat for a year prior to your purchase. You also indicated this was how you received the motor and upon new ownership(fish2day) the motor NEVER ran properly until you removed the silencer. You also indicated the previous owner said the carbs are original.

We really need more info...some Q's... Is the previous owner the original owner?

Can you verify his statements(he is a friend, etc), or is he just a seller and you'll never see him again?

Has he stated that the motor ran great when put away, or was this an as-is needs work motor?

Does he have ANY service records, or can he at least indicate which shop did his service work. Do you see where I'm going with this?

This IS solvable, however a better answer may depend upon the history that we can discover.

 

[dazk14]

Re: 1991 Johnson 200hp Air Silencer help needed...

What kind of boat?
This motor realy a 25 inch shaft motor?
Does motor have the model number on plug on rear of block?
Motor on a bracket?

Answer clanton's question above. Please report all numbers found.

 

[fish2day]

Re: 1991 Johnson 200hp Air Silencer help needed...

I do not have any history that will help. I purchased it from the family after the owner died. His son told me that he had been out in the boat with his Dad several times before he died, thats all I know. I do not think he was the original owner. So I don't think we can get any help from the history.
When I purchased the boat the main jets were partically clogged but the carbs inside were very clean. I blew out the jets with an air compressor and it started after getting fuel to the carbs. It would idle but when throttled up it would boog and struggle to reach 2000rpms. I had a boat tech to meet me at the water and he put a meter on hooked to each spark plug to verify the firing. It was firing good. We just happened to throttle up with the air silencer off and it began to run and reached 5000 to 5500 rpms. He put the air silencer back on and it booged and struggled to reach 2000rpms. He then removed the foam silencer gasket and it would run the normal rpms but something didn't seem exactly right. I was afraid of the hours it might take him to find the problem so I stopped there.
I ran the boat three times like this and it never failed to start but it was using unbelieveable amounts of Fuel, and would run stronger sometimes than other times. That is where I'm at now.

 

[fish2day]

Re: 1991 Johnson 200hp Air Silencer help needed...

Model # Plug at rear of block is 0431798.

 

[daselbee]

Re: 1991 Johnson 200hp Air Silencer help needed...

OK, so, he definitely has 200HP model carbs. (2 screws in throttle plates).

The 1991and earlier model carbs have two screws holding the side plates on. He has four screws, which puts him in the 1992, 1993 model years.

One model in 1994 had 4 screw side plates, but it also had an adjustable air bleed needle near the 11 o'clock position. He has not mentioned that.

So, it looks like he has either 1992, or 1993 model carbs.

Scanning for a match on the jets in 1992 or 1993, I cannot find any with the same jets he listed.

I would conclude that someone has re-jetted and made all three two sizes larger across the board.


So, if it were me, I would buy 6 54D HS jets and try those. They are the jets that flow most all the fuel and it sure seems like you are very rich.
If you get improvement, then work on the others, keeping in mind that the int and idle air bleeds will not have much effect with regard to your high speed mixture. Especially if you are only reducing by two sizes.

All of this is making a big assumption that the problem is carbs, and that your ignition system is working properly.

I will look today to see if I have anything for you to try. I might have an old engine with carbs like these....I just don't know.
If I do, I will let you borrow any parts (jets) to experiment with.

It is a long shot. I really don't know if I have it......but I'll look.

 

[dazk14]

Re: 1991 Johnson 200hp Air Silencer help needed...

Does the family know the marine mechanic that serviced the outboard? Earlier in the post you mentioned the carbs had been apart many times over it's history.
Let's get back to what you first experienced when you tried to run your newly acquired motor. Explain it's characteristics at idle/mid/high speed.
Before re-jetting, please pull the plugs and snap some pics and note how long the motor idled before you shut it down and if it was running with the silencer off. It's import that we verify this is systemic across ALL plugs and what they look like.

Is it using huge amounts of fuel with the silencer off?

The # you provided is the part # for a 200hp block, manufactured between 88-94.

Fwiw -1992 TX 200 carbs
56d highs - what you have
55 mids - MUCH LEANER than what you have
31 lows - a bit richer than you have now.

The throttle body is different between 91 and 92.

Something isn't adding up, since it appears something has happened after the deceased son had a boat ride and you fired it up.

 

[Joe Reeves]

Re: 1991 Johnson 200hp Air Silencer help needed...

Joe, you sure that he shouldn't go with leaner all the way around? down two sizes?

Daselbee.... Obviously I waited awhile to answer the above question. Frankly I'm really at a loss here and I've tuned, repaired, and completely overhauled a few of those 200hp loopers, and would swear that I know them inside out. It appears to me that someone has really screwed/tinkered with that engine in an attempt to upgrade its horsepower.

It's logical that, as you suggest, the jets should be resized so as to have it run leaner..... but my book of that model states that it requires jets that would obviously make it run richer (not logical with this engine).

Bottom line with me is that I don't have the answer. However if you can come up with a suggestion as to what jets might solve this problem (HS, Idle, Intermediate), I'll look in my remaining stock to see if I might just have the jets you suggest be installed as a test, and if I do, I'll donate them just to see what happens.

 

[daselbee]

Re: 1991 Johnson 200hp Air Silencer help needed...

Yes Joe, someone has monkeyed with this carb setup.
Note the jet numbers I posted which came from shop.evinrude.com,
Note the jet numbers you posted, which came from a hard copy manual,
Note the jet numbers that dzak14 posted, not sure of their source.

All the numbers are different, but dzak's numbers come from a '92 carb, and we were looking at '91 parts lists. His numbers agree with shop.evinrude.com.

OP, I looked today, and I have a 1993 225 down there. It has the 4 side screws, 3 throttle plate screws (225), it looked very promising.

It had intermediates of 55, idles of 36, and !!!!! Crap!!!! someone already stole the HS jets from it.

And guess what? Those Int and Idle jets DON'T MATCH WHAT the 'net says either!!!!!

So, I do not have anything for you to try. Very sorry.

You should also note that the throttle bodies MUST match the black plastic carb bodies. They are referred in the books to "carb assembly" and it is possible that someone has switched black carb bodies onto a different throttle body.

Whenever I run into a motor that absolutely will not respond to normal "fixing", it almost always turns out that someone has switched up parts for some reason.

 

[clanton]

Re: 1991 Johnson 200hp Air Silencer help needed...

The plug on rear of engine only had serial number, which indicates a replacement powerhead. The orignal powerheads have a model number and serial number. Call BRP with serial number from block and they can tell you what powerhead you have. At onetime when powerheads were replaced or rebuildt the main were bump up 2 sizes, I don`t know when or how this got started. This may be the cause for the jets being different.

Are you sure the seal is not covering any of the jets when installed?

 

[fish2day]

Re: 1991 Johnson 200hp Air Silencer help needed...

I really appreciate all the help. I was hoping some you Marine Techs could come up with a possible jet combo that might work. If anyone has them in stock I would be glad to purchase them.
Here are some pics that maybe will help.

 

[clanton]

Re: 1991 Johnson 200hp Air Silencer help needed...

Where does this boat live?

 

[fish2day]

Re: 1991 Johnson 200hp Air Silencer help needed...

pensacola, florida. No, I'm not sure the gasket is not covering any of the jets, I can place it on by hand tomorrow and check it. If the gasket was covering either the idle or inter jet would it cause it to do this because of starving for air??

 

[clanton]

Re: 1991 Johnson 200hp Air Silencer help needed...

Sure. You are in luck. I hang out in Panama City, Navarre, and Milton. I`m in South Florida until the end of April. I will look at the engine when I return to North West florida if you like. No charge I`m retired and like to stay clean, you will have to turn the wrenches.

 

[fish2day]

Re: 1991 Johnson 200hp Air Silencer help needed...

You have got a deal !!! And I will make up for your trouble if you can figure this out.
Rick 850-287-2103 rickylipham@gmail.com
Contact me when your ready and I'll get you directions.

 

[fish2day]

Re: 1991 Johnson 200hp Air Silencer help needed...

I took a closer look by placing the gasket on by hand, and it is not covering neither the idle nor the intermediate jet.

 

[dazk14]

Re: 1991 Johnson 200hp Air Silencer help needed...

To answer daselbee's question...where we fished out the info...
The jets from the service manual, and the block information from the BRP Dealer service line.

The OP will need to answer my questions and post pics of plugs, before we invest any more time on this.

 

[clanton]

Re: 1991 Johnson 200hp Air Silencer help needed...

I have not been able to look at this engine yet, but it had the wrong carbuators on the engine.

 

[skeeter beeter]

Re: 1991 Johnson 200hp Air Silencer help needed...

i have the same problem... 225hp carbs on a 200hp. runs like crap. 1986 200stlcdr.