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New 1409 Can't get high RPM's under load

J

Jfreeman1412

Regular Contributor
hey Guys I installed 2 new 1409 carbs and one runs like a champ and the other runs good until you get it up to 1600 rpms and then it doesn't want to go much higher. It doesn't spit or sputter but it just wont "r" up like the other engine will. And it takes more throttle to get it up to there than the other engine. Must be a carb adjustment issue? It "r" up fine with the other carb. What should I adjust Air Fuel Mixture? Thanks.
 
You can't adjust that. I suggest you switch carbs and see if it's the carb. I suspect it's not.

Jeff

PS: Are you sure the choke is opening?
 
Good Question.....My brother installed this carb and I figured he looked at the way I installed it and copied it. I will have to look.
 
Sorry for my Lack of knowledge, but can you break these down for me. I don't understand much of that. This is a brand new carb if that helps at all. Thanks
 
noelct said:
Check first fundamental, on the low rev engine is the carb wedge pointing in the correct direction?

Is the throttle cable stoking correctly?

What about the binnacle, working correctly?

,Noel.
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1. There is a wedge shaped mount that the carb is bolted to on the intake manifold. The wedge angle is there so that with the engine in its angled position, as mounted in boat, the carb will sit level. This will not be the case for a stern-drive. Make sure it is correct.

2. You have a cable that goes from the throttle lever (aka binnacle) to the carb. Make sure that it is moving in and out properly as you move lever. While you're there, make sure that throttle linkage on carb moves the same as good performing one. Disconnect cable from carb to test this.

3. Make sure that throttle lever (binnacle) is working correctly. When you move lever, cable should freely move in unison.

Lastly, does problem occur both in gear and out of gear?
 
Great...Thank you for you patients! I will defiantly look at that when I get back to the boat....It might be a couple weeks, as I am 6 hours away from it. Thank you for sharing your knowledge.
 
Like Jeff said....choke :D

By the way, where did you tap the power for the choke? Disconnect power to choke, loosen screws on choke, open choke (butterfly) by turning choke housing, tighten screws back...now the butterfly should be fully open. The boat should run fine with the choke disabled. Try it out :eek:

Report back to us :cool:...and blame it on your brother-in-law :p
 
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Awesome! Thanks.....Give me some Time I will not be able to make it back out to the boat until the end of the month, but I will definably let you know.

PS...I pulled power from the ignition side of the coil, and he suplosivley copied me, but I didn't look that close.
 
Ok Guys....I got to the boat and the electric choke was hooked up right and we adjusted it a few times, with little success. It then started dying and we changed the fuel filter and got some back. I can now run it at 2000 rpms, but it is not nearly as responsive and takes much more throttle than the other engine. The Starbird engine is very responsive and the Port is not. They both have new 1409 carbs. What could this be? Do I still need to make more adjustments or is there something else going on? Why does it take so much more throttle & less responsive?
 
Is the choke butterfly fully open when the engine is warm? Did you confirm this visually by removing the flame arrestor and looking?

-JJ
 
IF you have an anti-syphon valve, it will be in the fittings that attach the fuel line to the tank, If you do, remove it temporarily and see if that cures the problem.

Now, if that does NOT do it, then I'd start looking at ignition problems (bad wires, plugs, weak coil, etc.) Mr Carb gets blamed for lots of things it isn't doing!

Jeff
 
I dont believe I have a anti Siphon valve. I have one tank that feeds both engines and the one engine has never ran better, since I put the new 1409 on. The Port side has the problem.

Tonight I swapped the carbs and also Drilled and tapped the Carb on the Starboard Engine(the one that is running Great) and put it on the Port side. And obviously I put the Port side (Side with getting to higher RPM's) on the Starboard side. I have not run them under a load yet, but intend to in the morning. Both start and idle in neutral good in the harbor.

I did pull two spark plugs and found them to be grey. Like this: SP.jpgsp2.jpg

I also Changed the Coil on the Port (Problem) Side, because I had a brand new one that was in the extra/spare parts cubboard in the boat when I bought it. I will report back to as soon as I get back tomorrow. Thanks.
 
OK Guys We ran it and we got 2000 RPM's out of it and it was doing the same thing. This is more RPMS than we were getting at 1600 RPM's. But it still is not performing like the Starboard side. I will say that the plugs on the other (Starboard) were black and slightly wet looking. At this point I think we can eliminate the carb. I changed out the Coil. I will say that this is the same motor that sprays out and does not "pour" out like the starboard side. I am not sure that this has anything to do with it, but I thought I would expose all possibilities.
 
You said you were running both engines from one tank. Do you have 2 fuel pick ups or are you trying to run both engines from one pick up?
 
Check fuel pump pressure and volume?

"Soft" fuel line closing up or clogged filter?

Exhaust blockage?

Distributor advance locked up?

ECU failure?

Firing order correct?
 
I don't know, We have ran it like that since we have bought it. Saying that, there is nothing saying that there isn't something that got sucked up into the intake tube partially blocking the flow. However the starbird engine runs great and the gas line going to that sides is slightly longer. Frustrating!

Check fuel pump pressure and volume?
Exhaust blockage?
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I will definatley will be checking these two things. This engine will tend to run hot from time to time and there was water in the gas this spring when we put it in the water.

Does the White spark plugs indicate a lean or gas starvation at all?
 
I'm assuming the boat was run that way for years with no issues.

With the motors stopped, remove your flame arrestors and make sure your secondary butterflies are opening at full throttle.

Maybe your cables aren't setup correctly.

-JJ
 
I do believe. I bought it like that last year.

With the motors stopped, remove your flame arrestors and make sure your secondary butterflies are opening at full throttle.
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Are they the butterflies that the choke flap is not on?

There is only one throttle cable and one gas line (other than the choke wires) that gets attached to install these carbs. At least that is all we did attach.
 
I could be wrong, but I still believe your problem is the single pick up. I would run the engine your having trouble with on a portable tank and continue to run the good running engine on your boats tank and I'd almost bet your problem will be solved. If you do try it please let everyone know the results.
 
I could be wrong, but I still believe your problem is the single pick up. I would run the engine your having trouble with on a portable tank and continue to run the good running engine on your boats tank and I'd almost bet your problem will be solved. If you do try it please let everyone know the results.
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I was thinking that same thing! I am going to bypass everything right to the fuel pump and see if that does it. I will do that when I get back out next weekend. Thank you for the suggestion.

I will defanitley let everyone know when and what solved this. I am thankful for all of the help.

Here is a picture of how far the throttles get off. Don't let it fool you too much, they are pretty even until you hit about 1/3 throttle and the starbird side keeps gaining rpm's and the port side takes more throttle but doesn't gain any R's.

AAA.jpg

The one that has less throttle is the starbird and the one that has more throttle is the Port side.
 
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I'm assuming its a 70s vintage boat? We didnt stumble onto a twin engine single pickup issue after 30a years.

Were the carbs you replaced 2 or 4 barrels? If they were 4 barrels and ran with a single pickup, then its probably not your issue.

Yes, your secondary barrels are the ones without the choke flap.

-JJ
 
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