my Johnson 90 idling RPM? on hose and in water??

[ib18]

I am trying to get my 1982 Johnson 90 v4 2 cycle ready to go fishing. It died after 4 minutes idling after 3 months of sitting. What is the idling speed RPM for both on a water hose vs. in river?

I thought I saw 1,000 RMP on land and 800 in river?

but My little kicker motor - a 1999 Honda 8 hp 4 stroke was almost choking when I slowed it down to 1,000 RMP in a bucket and it was idling better at 1,500??

so, does anyone know what is the ideal RPM for my little kicker motor to idle at in a bucket and in river?





Thanks.

 

[racerone]

?---1500 RPM is NOT idling at all.----Best to look into the carburetor as the wee jets are likely plugged from sitting with fuel in the bowl.

 

[ib18]

Thx.
i just removed and cleaned the jet hole and the idle mixture screw. It would only stay running for 5 seconds before that. Now it can idle at around 1500. I will try slowing it down to 1000 after work today and see what happens.

does it matter my bucket’s water is warm. It was sitting outside all day.

 

[Mohawkmtrs]

Honda book says 1200 rpms (+/- 100) in neutral after warm up.

 

[ib18]

Honda book says 1200 rpms (+/- 100) in neutral after warm up.

Thanks a lot. I wonder whether that is on river or on a hose (in a bucket).

 

[Mohawkmtrs]

In a river/lake...exhaust back pressure will affect idle (unlike on a hose).

Besides, you operate it in the body of water...can't go too far on a hose

 

[oldboat1]

don't know if you are being literal referring to a bucket, but should use a something the size of a barrel -- plastic trash can works. Idle or fast idle only, hose running. Water well above water pump -- 6 inches or so. Half way up the leg is good.

 

[ib18]

My Johnson 90 cannot idle below 1250 rpm on a water hose. Is this normal?

 

[racerone]

Not normal.-----Your motor needs work, lots of it I believe.-----Should just purr at 650 RPM in gear.-----Your tachometer is reading accurate numbers ?

 

[Joe Reeves]

Bucket?? Better be a hellava big one!

Idle rpm on a flushette.................
Long shaft (20") 1000 rpm
X Long shaft (25") 1200 rpm

The idle in the water will drop to normal.

If your engine won't idle at those settings (whichever)... you have a engine problem.

 

[ib18]

Not normal.-----Your motor needs work, lots of it I believe.-----Should just purr at 650 RPM in gear.-----Your tachometer is reading accurate numbers ?

No idea. Its a chinese made from ebay.

this is neutral on water hose. Will get a reading again when i go boating again

 

[ib18]

Bucket?? Better be a hellava big one!

Idle rpm on a flushette.................
Long shaft (20") 1000 rpm
X Long shaft (25") 1200 rpm

The idle in the water will drop to normal.

If your engine won't idle at those settings (whichever)... you have a engine problem.

Its a long shaft. It was idling beautifully until i tore apart the carbs and rebuilt it. I will take a reading when i go boating again. Yes this was on a water hose.

 

[Joe Reeves]

I'll try to keep track of you on the board. The message setup of iBoat's is a little hectic to navigate.

 

[ib18]

I'll try to keep track of you on the board. The message setup of iBoat's is a little hectic to navigate.

yes, there used to be a "your post" in profile so you can eaily find your posts. But, they got rid of that feature in the profile.

My little Honda 8 hp 4 cycly can go WOT at 5 miles per hour (2 of us on board less than 300 pounds combine) vs. my Johnson 90 hp 2 stroke 30 miles an hour in wide open throttle. Boy, what a difference! So, kind of inpatient but need to try this outboard so I just kept running it for the last trip. Big 90 hp is a must to get me from point A to point B faster - LOL

So, is my little Honda 8 hp 4 stroke speed normal at WOT?

 

[Joe Reeves]

Its a long shaft. It was idling beautifully until i tore apart the carbs and rebuilt it. I will take a reading when i go boating again. Yes this was on a water hose.

Assuming the compression is approximately 100 psi and fairly even on all cylinders... and with all the spark plus removed, the spark will jump a 7/16" gap with a strong blue lightning like flame... a real SNAP! (Check it)...........

Let me know what the compression is on all cylinders, and if the spark is as it should be... as above.

Therein your quote lies a clue you know. Assuming you cleaned all the jets thoroughly, including the two (2) high speed jets in each carburetor.... and not intending to insult your intelligence BUT... are you sure that you got "all" of the jets reinstalled in their proper location? A very easy mistake to make (Don't ask me how I know).

(Read the NOTE below before you do this)
The synchronization between the carburetors is pretty close to critical as is the relationship to the timing. Back the cam away from the roller... now make sure that the linkage between the two carburetors is set so that both throttle butterflies start to move as the same time... and also close at the same time. When closed, double check to make sure that the linkage between the carburetors isn't slightly too tight whereas one throttle might be closed and the other ever so slightly open.

Now, re-adjust the carburetor throttle cam roller so that the throttle butterflies just start to open when the scribe mark on the metal cam is dead center with the roller.

NOTE: The roller of yesteryear was a one piece roller, approximately 3/8" in diameter. Today's rollers, perhaps yours, are manufactured of two substances... a small black roller which is covered with an inferior clear plastic covering to bring its diameter up to the 3/8" size. The inferior clear covering breaks away resulting in the rollers diameter dropping to the approximate 1/8" which throws the engine/carburetor out of synchronization which in turn makes it impossible to function properly. (Check It!)

Let me know what you find.

 

[ib18]

Your explanation is over my head. Joe. Gosh, I really don't want to do anything extra unless this little kicker breaks again. I had it out and idled the kicker while I try to set up my Raymarine Axiom 3D fishfinder, my radio etc. becuase I remove and re-install everything from my boat for every trip. So, they don't get stolen. It is super time consuming. I spend at least 30 minutes to hook and load everything up so I can go fishing. Kind of a big pain in the butt. The Johnson 90 idled but died which is not NORMAL, but the Honda 8 hp just kept idling and never died. So, I know I still need to clean the Johnson 90 carb again to make it idle properly, but I am totally done with messing around with the small outboard. I want to spend more time fishing than boating - LOL
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