[DennyDen]

Hello Everyone...Does anybody Know what the Idle Speed should be on my 1988 Carver Mariner....The engines are Mercruisers 5.0 Inboards with thunderbolt ingnitions...230 Hp....I'm guessing somewhere between 600 and 700 Rpm's would be correct...But is that in gear or in neutral...Thank You...Dennis

[NYCAP123]

Originally Posted by DennyDen

Hello Everyone...Does anybody Know what the Idle Speed should be on my 1988 Carver Mariner....The engines are Mercruisers 5.0 Inboards with thunderbolt ingnitions...230 Hp....I'm guessing somewhere between 600 and 700 Rpm's would be correct...But is that in gear or in neutral...Thank You...Dennis

Neautral.

[Fireman431]

I'm not sure about the 350, but my 7.4 is supposed to idle at 800 in neutral and 750 in gear.

[DennyDen]

Thanks Guy's, For some reason the P.O. had both motors set at 550 rpm's in neutral and lower in gear...I kicked it up to around 650 seems alittle better at the dock now.......Den

[Fireman431]

According to a Cycler manual (if yours has carburetors), it should idle 650-700 in neutral.

[tommyfmu]

Hi, I have Crusader 350 XL's , 5.7 L . I know how to adjust idle in neutral, but can anyone tell me if there's another screw on the carb's to adjust for when in gear? My port engine in gear is at about 500 rpm, but my stbd engine drops to about 250. Thanks, Tom.

[NYCAP123]

Originally Posted by tommyfmu

Hi, I have Crusader 350 XL's , 5.7 L . I know how to adjust idle in neutral, but can anyone tell me if there's another screw on the carb's to adjust for when in gear? My port engine in gear is at about 500 rpm, but my stbd engine drops to about 250. Thanks, Tom.

At 250 you're getting ready to stall. Yes there is, but if you're asking about that I would suggest you bring in a mechanic to make the adjustment this time and watch over his shoulder. There could be other reasons for that low RPM and a carburator can be a dangerous thing to mess with. I'm sending you a PM.

[Fireman431]

I have been wrenching on auto/marine engines for a while and have never seen one with a seperate screw for idle-in-gear. Usually, the idle is set in Neutral and it is going to drop lower while in gear due to the increased drag on the engine from the transmission clutches.

Most newer (early 90's & up) have idle control solenoids to assist in keeping the engines at the right RPM and that could be your issue.

If you're idling in Neutral at 550, bump it up to 700 RPM (where the specs say it should be) and see how it does in gear. That should also help you're handling around the dock as well because the props are actually turning while trying to fight wind/current.

[NYCAP123]

This may be found to be enlightening.
http://www.aa1car.com/library/carburetor.htm

Be sure to watch the video.

[tommyfmu]

NYCAP, thanks for the reply and PM info ; believe it or not, even at 250 and in gear without stalling is a big improvement after I cleaned both flame arrestors last night which were filthy black, changed fuel filters and added fuel stabilizer because of old gas that was just sitting for a long time. Huge improvement from the cleared air intake; both engines would stall when maneuvering in idle before, but last night in gear neither stalled.

Fireman, could the solenoid you're talking about be a black box next to the carb that says 'electronic timing module' or something like that?

[NYCAP123]

Had an ETM go once (on a Carver with Cummins). It was explained to me that it's like a "brain" (Pricey little thing as I remember), not a selanoid (had a bunch of those go bad...also on a Carver, but with Volvos) which atomize the fuel through jets.