1969 Merc 800 Idle speed

[Hamhouse]

Just finished a restoration of this motor and for some reason I cannot get it to idle down. I had to adjust the throttle cable and throttle arm linkage to force the throttle back to normal idle rpms when the throttle handle is in neutral, but after you drive it a bit the idle speed is racing again. Each time, there is the smallest amount of movement in the throttle/distributor when checking under the hood with your hand. What could have changed that is causing this? I had the whole distributor apart for new bearings and a new rotor so it was apart all the way. I have checked the positioning of the two halves of the dist/throttle linkage to ensure they were assembled right and there are no problems there. The timing has been set, the advance hits it's stop and the economizer rotates the remaining amount correctly. All appears fine, and since I'm used to seeing throttle linkages that always return to zero I'm perplexed. Note that the throttle cable adjustment I am talking about has it adjusted all the way to one end of the adjustment screw so all my instincts tell me this is wrong.
Please help.
Thank You

 

[racerone]

Recheck timing of belt on distributor.

 

[1960 Starflite]

Agreed, my 1975, 850 (new to me) idled high also. Took it to marine mechanic, he said too many hands on engine. Wasn't any better after he "worked" on it. I obtained a manual, long and short of it, timing off 1 tooth on distributor pulley. The idle rpm is controlled by timing.

 

[Hamhouse]

Agreed, my 1975, 850 (new to me) idled high also. Took it to marine mechanic, he said too many hands on engine. Wasn't any better after he "worked" on it. I obtained a manual, long and short of it, timing off 1 tooth on distributor pulley. The idle rpm is controlled by timing.

OK thanks. So I need to retard it one tooth right?

 

[racerone]

No .------You need to check it first !

 

[Hamhouse]

No .------You need to check it first !

I have checked it and I have used a service manual to get the settings/procedure. This is one of those engines with 2 timing light marks on the flywheel, one for alignment during assembly and one for timing adjustment with engine running. I have noted that later models do not use this two mark system, therefore I wonder if this one really doesn't need it either. One tooth on the belt would be about the same as the distance between the timing lines.

 

[Hamhouse]

I have checked it and I have used a service manual to get the settings/procedure. This is one of those engines with 2 timing light marks on the flywheel, one for alignment during assembly and one for timing adjustment with engine running. I have noted that later models do not use this two mark system, therefore I wonder if this one really doesn't need it either. One tooth on the belt would be about the same as the distance between the timing lines.