9.9 Evinrude, won't go over 3000 RPM

[DeanHensler]

I've got a 1992 Evinrude 9.9 electric start remote controlled engine. I have been battling and battling this motor. I finally got the thing to idle and run consistantly, but it won't go over 3000 RPM in forward gear with full throttle. I've insured that all the linkage is correct. The roller ball on the carb is wide open when the timing plate is maxed with full throttle.

In reverse it only turns 1500 RPM, which barely moves my pontoon boat.

Anyone have any ideas? I've insured the fuel pump is working just fine, its getting good spark to both cylinders, the carb has been removed and cleaned. I'm out of ideas...

HELP! PLEASE

 

[Rick.]

Re: 9.9 Evinrude, won't go over 3000 RPM

I know they have a rev. limiter for neutral and reverse so I'm not surprised you aren't getting full rpm in reverse. Have you checked the spark with an adjustable gap spark checker? It should jump 3/8 of an inch and be blue/white and snappy. These motors do run well on one cylinder but they lack power. I've never tried to push anything so heavy with a 9.9 so I'm not sure if that would affect the rpm or not. It's not uncommon to have to clean a carb. more than once but before you do wait and see what others have to say. Best of luck. Rick.

 

[DeanHensler]

Re: 9.9 Evinrude, won't go over 3000 RPM

It's not a rev limiter in neutral and reverse, it's a throttle stop. Its getting as much throttle as allowed in reverse and in forward gear.

 

[82rude]

Re: 9.9 Evinrude, won't go over 3000 RPM

you could have a spun prop.though im not too sure of that .you may also have to really drop your pitch because your trying to move a big object.

 

[boobie]

Re: 9.9 Evinrude, won't go over 3000 RPM

How are you checking your rpm ??

 

[Rick.]

Re: 9.9 Evinrude, won't go over 3000 RPM

It's not a rev limiter in neutral and reverse, it's a throttle stop. Its getting as much throttle as allowed in reverse and in forward gear.

OK. What does a throttle stop do? Rick.

 

[DeanHensler]

Re: 9.9 Evinrude, won't go over 3000 RPM

How are you checking your rpm ??

The boat console has a tach built in.

You can tell by the sound of the motor that it isn't running as hard as it should. When you first put in in reverse and give it full throttle it jumps to 2000 RPM, then slowely drops down to 1500 and then holds there.

 

[DeanHensler]

Re: 9.9 Evinrude, won't go over 3000 RPM

OK. What does a throttle stop do? Rick.

Its connected to the gear shifter. When you have it in neutral it only lets the throttle go so far. When you shift to reverse it moves up and allows the throttle to advance a little more. When you shift to forward it drops all the way down out of the way and let's the throttle go wide open.

Here is a picture with the arrow pointing to the throttle stop, snagged from Leeroy's Ramblings.

 

[the machinist]

Re: 9.9 Evinrude, won't go over 3000 RPM

These motors run suprisingly well on only one cylinder, which may be your situation. Yes, you may have spark, but is the plug good & firing?

 

[DeanHensler]

Re: 9.9 Evinrude, won't go over 3000 RPM

These motors run suprisingly well on only one cylinder, which may be your situation. Yes, you may have spark, but is the plug good & firing?

I just put 2 brand new Champion L82C plugs in it this morning. Same exact problem still exists. When I first put it in reverse and give it full throttle it will jump to about 2000 RPM, then drop down to about 1200-1500 and hold there. When I put it in forward with full throttle it goes to 3000 RPM and stays there.

Here is a quick video I shot today showing the motor running. I attempted to pull the bottom spark plug wire with it idling but it died. I did the same thing with it at full throttle and it did keep running, but a lot rougher. Shocked the hell out of me when I pull the plug wire with full throttle too. This tells me that both spark plugs are firing.

What is the spark plug gap supposed to be on this motor? I'm at .035 right now.

Note when I pulled the brand new plugs out after only running the engine for about 2 minutes, they were very wet with gas/oil. I think this thing continues to flood itself out.

Note 2: I ran out of gas while messing with the motor today. Right before I ran out, the engine took off and ran up to 5000 RPM in forward, then died as it ran out of gas. Strange... I thought for a minute the problem was magically fixed, but after refueling, the same problem continues.

 

[Scurvy Knave]

Re: 9.9 Evinrude, won't go over 3000 RPM

when you put the carb back on, did you seat the float properly parallel to the carb body?

 

[DeanHensler]

Re: 9.9 Evinrude, won't go over 3000 RPM

when you put the carb back on, did you seat the float properly parallel to the carb body?

Man, I think so... What are your thoughts here? If it wasn't seated correctly what could be happening that would cause the motor to flood itself out?

 

[AlTn]

Re: 9.9 Evinrude, won't go over 3000 RPM

usual observation for the motor to rev like that when they run out of gas in the carb as the gas/fuel mixture goes lean...if your float level is off and is allowing too much gas into the bowl it will result in a very rich mixture possibly to the point of flooding...too little gas and the mixture may be too lean for ignition to occur...the float should be parallel to the carb body when the carb is inverted < bowl off >...slightly higher on the free end of the float is optimal,but that's a subjective measurement...the float should have the tab on the hinged portion of the float arm pointing upward towards the carb body

 

[Tim Frank]

Re: 9.9 Evinrude, won't go over 3000 RPM

I've got a 1992 Evinrude 9.9 electric start remote controlled engine. I have been battling and battling this motor. I finally got the thing to idle and run consistantly, but it won't go over 3000 RPM in forward gear with full throttle. I've insured that all the linkage is correct. The roller ball on the carb is wide open when the timing plate is maxed with full throttle.

In reverse it only turns 1500 RPM, which barely moves my pontoon boat.

Anyone have any ideas? I've insured the fuel pump is working just fine, its getting good spark to both cylinders, the carb has been removed and cleaned. I'm out of ideas...

HELP! PLEASE

1) Has this motor ever run satisfactorily FOR YOU?
2) Gap should be 0.030"
3) Did this motor always go on this pontoon? i.e. was the motor propped for this application?

 

[Scurvy Knave]

Re: 9.9 Evinrude, won't go over 3000 RPM

What conditions are the valve needles and seats in? You may have cleaned them, but a bent, nicked, rounded or worn high speed jet needle or seat will deliver too much gas and flood. turning in the knob on a bad needle may give unpredictable or non-linear results because the profiles no longer match and the apertures may be irregular.

Surging on lean is not uncommon for ICE's.

If everything fuel related checks out, then consider timing (see timing article in Secret Files) and gaps.

Finally, Tim's point #3 is good. Is the prop appropriate for the load. 9.9 to push a displacement hull might be forcing her a bit given the prop.

 

[DeanHensler]

Re: 9.9 Evinrude, won't go over 3000 RPM

Surging on lean is not uncommon for ICE's.

What are ICE's?

The guy I bought this motor from ran it in a tank for me. I couldn't tell hom any RPM it was turning and may have thought that 3000 RPM sounded good in the tank. Now that it is on my boat I can tell it doesn't sound right.

The motor was previously on a pontoon boat just like mine. The prop is not the issue. The issue is too much fuel. I'm going to perform a test by taking the boat out and running it full throttle in forward, then disconnecting the fuel line. I'll let it run out of gas and see if it takes off right before it runs out of fuel. If it does this again, I'm fairly certain the problem is that it's getting flooded. The question is WHY.

 

[Scurvy Knave]

Re: 9.9 Evinrude, won't go over 3000 RPM

ICE is internal combustion engine.

chances are the motor will surge as it runs out of gas. This often happens with all kinds of motors (just Google "lean surge" if you don't believe me)

If you are confident that the issue is too much fuel and not spark related, then assuming that the carb (float valve, needles and seats) checks out you should be able to turn the high speed jet in to lean out and prevent excessive fuel. Also, two other possibilities:

1. If your motor has a quick start function it could be malfunctioning.

2. is your choke plate stuck?

 

[kbait]

Re: 9.9 Evinrude, won't go over 3000 RPM

No adjustable high speed jet on that motor. Ensure that your main jet is clear, and your float is set correctly. 50/1 fuel-oil mix. Video sounds like it should turn more rpms at WOT. even w/heavy load.. as evidenced by your running out of fuel and gaining a bunch of rpms..

Before you install the cleaned/set carb, blow in the fuel inlet nipple. Air should pass when the carb is upright, and NO air should pass when you blow through w/carb upside-down. If any air can pass when inverted, look to your float valve (needle-seat).

Good luck!

 

[BoatingCop]

Re: 9.9 Evinrude, won't go over 3000 RPM

Just an observation that I made is that boat is huge for that engine. If you have the factory prop on that engine, I don't think you'll see WOT RPM's consistent with what the factory says they should be. What size prop is on it?

 

[BoatingCop]

Re: 9.9 Evinrude, won't go over 3000 RPM

By the way, check this site out. There's more information than you ever wanted to know about the 1974-1993 9.9/15 hp's. OMC outboard related articles