Additive for rough idle/warm bogging?

J

JeffsAV

Seaman
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Dec 6, 2008
Messages
59
I recently found this; http://www.goldeagle.com/brands/start_your_engines/default.aspx

I am wondering if this will help to smooth my idle, and generally clean out my 1977 70HP Johnson. It cold starts great, but it will idle a little rougher than I think it should. I have also noticed that it will bog and die if I push the throttle down too fast after being run across the lake, stopped a few minutes, and restarted. I have to really ease into the throttle and let the engine s l o w l y build up RPM's.
 
T

tx1961whaler

Vice Admiral
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May 31, 2008
Messages
5,197
Re: Additive for rough idle/warm bogging?

Probably doing an engine decarb with Seafoam would be better. If you do it on the lake, people will look at you like you're clubbing a baby seal to use for bait (it smokes ALOT), but usually your engine runs smoother after burning the gunk out of it.
 
Mas

Mas

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Re: Additive for rough idle/warm bogging?

Sounds like fuel delivery to me...being that rpms eventually build up. Try pumping the fuel bulb as you accelerate. If you get better rpms...look to your fuel pump. Also, a gummed up carb can exhibit the same issues until the carb begins to deliver fuel from the high speed jet.

When was the carbs last rebuilt?

MAS
 
tashasdaddy

tashasdaddy

Honorary Moderator Emeritus
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Re: Additive for rough idle/warm bogging?

it sounds like you are due for carb cleanings, and rebuild kits. nothing is going to clean a dirty 2 stroke carb other than dismantling, and rebuild kits. Seafoan is for decarbing the engine, and with clean carbs, will keep the carbs and engine clean. http://forums.iboats.com/showthread.php?t=244013
 
J

JeffsAV

Seaman
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Messages
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Re: Additive for rough idle/warm bogging?

I think it may be running too rich(purely uneducated guess). As I am trying to accelerate after warmup/restart, I momentarily choke it, and it wants to die immediately with choke, but then surges a very tiny bit a second or two after I have let off the choke. I pump the bulb, and it has no effect. In neutral I idle it up to 2000-2500 RPM for a few seconds, let it come back down to normal idle, and it seems to clear out the extra fuel(another guess), and then it runs a little bit better and accelerates more quickly. Does this make any sense, or am I chasing my tail? I am also curious if the additive I mentioned will do any harm to try running through my motor as a stop-gap/trial for a band-aid fix.
 
tashasdaddy

tashasdaddy

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Re: Additive for rough idle/warm bogging?

probably not, but will be a waste of money. if you want to add something add seafoam. but with out cleaning the carbs properly, it will be a waste of $$$.
 
U

U-turn

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Mar 7, 2009
Messages
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Re: Additive for rough idle/warm bogging?

JeffsAV said:
In neutral I idle it up to 2000-2500 RPM for a few seconds, let it come back down to normal idle, and it seems to clear out the extra fuel(another guess), and then it runs a little bit better and accelerates more quickly.
Click to expand...
Jeff-
This sounds like the same issue I'm having with my 65 hp Johnson. Let us know if you figure it out, I've just replaced my reeds and rejetted (I was getting some decent spit-back, but my reeds weren't broken). Hopefully I'll see how mine now runs in the near future.

Good luck!
 
U

U-turn

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Messages
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Re: Additive for rough idle/warm bogging?

BTW-
What altitude are you operating at? I noticed that my problem(s) was worse when I switched from sea level to 2000' last summer.

Cheers
 
tashasdaddy

tashasdaddy

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Re: Additive for rough idle/warm bogging?

you should have not problems with original jets.
 
M

marquette

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Apr 18, 2006
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Re: Additive for rough idle/warm bogging?

i'd say try it. it's made by the same people that make Stabil and we all trust it. it only costs a few bucks and takes no effort to dump it in the fuel tank and run around the lake for a while. if it doesn't work you are no farther behind and if it does you can come back here and tell us you have found a miracle cure. i'm with TD in that i don't think it will work but why not satisfy your curiosity. most people didn't think Stabil would work until someone tried it and now we all use it.
 
Silvertip

Silvertip

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Sep 22, 2003
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28,764
Re: Additive for rough idle/warm bogging?

I would not waste my money on that stuff. Notice the label that indicates "revitalizes fuel".. That is B as in B, S as in S. Bad fuel is bad fuel. Use Stabil or SeaFoam BEFORE storage to prevent the fuel from going sour. Once it is sour, it stays sour. What you really nead is a thorough engine tune up, carb rebuilding, link&sync and a decarb, as mentioned, wouldn't hurt either.
 
CATransplant

CATransplant

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Feb 26, 2005
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6,319
Re: Additive for rough idle/warm bogging?

Folks have been selling one "Tune-up in A Can" or another since the internal combustion engine was invented. Mostly, they don't do much, but folks like to try them instead of doing a proper carb cleaning and ignition tune-up.

It won't hurt your outboard, but you'll still have to do the real tune-up.
 
J

JeffsAV

Seaman
Joined
Dec 6, 2008
Messages
59
Re: Additive for rough idle/warm bogging?

I ran that stuff through the engine, and it did help slightly. I had checked my spark plugs beforehand and they were coated with carbon buildup. I made the run with the additive mentioned, and checked the plugs after. The plugs were MUCH cleaner...no joke. I changed them anyway, and the new plugs made a huge difference on how the engine ran. Idle is very smooth, power is instant and steady, and trolling speed is even smoother. Go figure, huh? I don't think the additive hurt anything, and from what I saw it do to the plugs, it looks like it cleaned up the fuel path pretty well. I guess the combination worked like I had hoped.
 
U

U-turn

Cadet
Joined
Mar 7, 2009
Messages
16
Re: Additive for rough idle/warm bogging?

Thanks for the follow-up. I was just curious where you bought the additive that you used? I'm getting ready to break mine out of winterization. Glad it worked out for you.
 
J

JeffsAV

Seaman
Joined
Dec 6, 2008
Messages
59
Re: Additive for rough idle/warm bogging?

I bought it at a local surplus hardware store called Bargain Depot. It is available through online retailers also.
 
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