J10Rena engine

[ba_50]

Joe,

1992 Johnson 9.9 J10RENA idles great but only makes a half hearted attempt to get a 14’ aluminum fishing boat up on plane. It ran great when I first got it (used but low time)

A mobile mechanic thought it was burning too rich since leaning the carb needle made it run better. He was supposed to come back and check the carb but never did. I think it burned a gallon of gas going about 2 miles with the throttle at 2/3 trying to clean it out.

FR-yes, it runs on both cylinders
It has a new carb kit (3yrs old but not really used, no pin holes in diaphragm that I could see) and looked over by an auto mechanic, updated redesigned carb cover, proven fuel pump( haven’t tried it yet and no leaks in either pump).
New spark plugs, fuel lines, and use an inline fuel filter.

7/16" spark jump
I adjusted the idle cam screw to be on the mark when the throttle started to open and at full throttle the roll pin is straight up and down. It helped some because at full throttle the motor lost power then came back up some when reduced before. Squeezing the fuel bulb doesn't help get any power.
I put soap suds on the gaskets looking for blow by and they looked ok.
Compression was 122# and 120# the last time I checked.
The float was adjusted per specs in the OMC manual
flywheel key was ok
Tried two different coils off a different motor
Plug and coil wire continuity was ok.
New head gasket

Tried sea foam.

It ran fine before I got that new carb cover. The original roller broke. The new one is an upgraded version and has a plastic pin for the roller.

I don’t have a DVA adapter or timing light.

RacZekp1 wrote:

1. hi,
here is a carb photo taken from http://www.sschapterpsa.com/rambling...lings.html.its model 89, but earlier carb models are symiliar

when botl no 1 is screwed to far, cause throttle leaf in carb troath(there are 3 small holes at upper inner carb wall) open more then 1 hole.
play with screw no 1 and no 2 (I'm not sure how to transfer the photo but he is talking abot the right hand cam adjustment screw next to the link as #1 and the left side as #2



I’ve read the SSchapter several times

My 3 new ideas are 2 new or different plugs (again), a proven fuel pump and what RacZekp suggested but I’m not sure how I would adjust them.

I have to borrow a boat to test the motor.

 

[F_R]

Re: J10Rena engine

Nowhere in that long story and all that work do I see where you checked to see if it is running on both cylinders. That would have been the first thing I would have checked.

 

[Joe Reeves]

Re: J10Rena engine

It ran fine before I got that new carb cover. The original roller broke. The new one is an upgraded version and has a plastic pin for the roller.

This is the part that caught my eye. Like having a car that runs perfect, you change spark plugs and then the car runs lousy.... Hmmm.

There are two top plates for that carburetor... Early production & Late production. There is only one gasket listed for both (unless a gasket comes with the plate).

Plate: Early production = 336049 Supercedes to 433973 ($88.30 in 2010)

Plate: Late production = 337883 (Does not supercede) ($8.96 in 2010)

One Hellava Difference In The Above Prices!!

Gasket = 334043

Possibly you have the wrong plate. Install the old plate momentarily to observe the difference.

 

[AlTn]

Re: J10Rena engine

"it ran fine before I got that new carb cover"..I fooled with an evinrude of that model no. ba , but it wouldn't idle and would die frequently at wot...I learned this from that experience...the float height with the carb inverted had to be increased almost 1/4" from the hinged end to the free end, in other words, it wasn't close to level...also, for some unknown to me reason, omc decided that they would use a ball socket end on the idle adjust screw..HB had them in a pack of specialty bits for cheap, though the driver handle lacks a lot.
I wonder if you have the carb top and gasket for the 9.9 or 15..or even if it would make a difference? Marineengine.com has a diagram of this carb if you need to check part numbers. Seems like I had that carb off an on at least 4 times before it was halfway right.
Do both plugs look the same?

 

[ba_50]

Re: J10Rena engine

The original top had a roller that was held on by a screw and it broke off. I found a picture of it and it looks like 331735 but I'm not sure if the number is the original.

The numbers you came up with are the same ones I did from evinrude.com 336049 and 337833. I have the last one. Actually it is a kit #435356 with a needle for both a 9.9 and a '92 15hp.

Looking at SSchapters again, it states that repair kit 433973 replaces 331735. According to SSchapters, the '92 is a late production carburetor. These aren't even mentioned on Evinrude's website.

I talked with two dealers and one didn't know and the other one said 337833 when I first started looking.

Very confusing isn't it?

F_R, in case you didn't see my re-edit, it was firing on both cylinders.

 

[raczekp1]

Re: J10Rena engine

maybe best way is to buy an old type carb?
look on ebay

 

[ba_50]

Re: J10Rena engine

I guess I'm not the only one that can't figure that top business out.

A post from Caber-Fedh on glen-l.com suggested pinching the fuel line between the fuel pump and carburetor or pulling the fuel line off while running at WOT 3x. If it gets a power surge when the fuel runs out it indicates a very rich mixture. Makes sense to me.

 

[Tim Frank]

Re: J10Rena engine

Just a suggestion....going back and editing your OP is going to be confusing to many people; not sure why you would do that, but it may be better just to "build' the thread in its normal sequence so that potential problem-solvers don't get confused and simply dial-out.

 

[25xs]

Some suggestions...

Some suggestions...

I don't think the new cover is intended for installation on the "early production" carbs... That is why the early production replacement cover is priced so high; as incentive to simply upgrade the entire carburetor to the late production style. I agree with the advice to reinstall the old cover and operate the throttle shaft manually (your cam is broken, I understand) to see if the problem goes away.
Also, your mobile mechanic apparently doesn't realize the high speed jet is a fixed orifice? Adjusting the screw on the carb front when you mention it idles fine made no sense. "He's fired"

There is no mention of care taken while changing the cover... Any chance you simply need a thorough carb cleaning & reassembly? I would also replace the "Nozzle, top&bottom gaskets and the idle tube" prior to reassembly. A hairline crack in the nozzle well, or the idle tube (common occurance) can cause hair-pulling symptoms such as yours.

Tom

 

[ba_50]

Re: Some suggestions...

Re: Some suggestions...

Tom,

I don't have the original top anymore.

There is a hairline crack at the top of the nozzle tube alongside the metal insert, like maybe it cracked when the metal was pushed in. It didn't look like it would cause a problem, since the insert should block any leaks. The nozzle well gasket is kind of limp but not to bad that I can see. The carb has been cleaned and/or soaked in Gunk cleaner at least 10x and a fine wire was gently used in all the holes. The cover screws were put back according to the numbers on top. One thing I don't like about this top is the plastic is uneven all the way around. Maybe the gasket makes up for it but it seems like a bad idea.

I would still have to spend about $50 on a guess that the nozzle is the problem.

Tim, Are you suggesting I re-edit the first post with an update each time? I guess it wouldn't hurt, but the readers will probably read it all anyway if they are really interested. I figure it might be just as confusing to have the information out of order. I know that when there are lots of suggestions, it is hard to sift through them all.