1969--85hp Starflite, model 85993E possible carb swap?

[68glasspar]

Are the carbs for the newer mid 70's 85hp that don't have idle/slow speed mixture screws interchangeable with earlier models? Where the carbs with fixed mixture less troublesome?

Whats the correct/recommended spark plugs for the 1969 85hp?

 

[jimmbo]

In the Mid 70 and 80s, a lot of Owners were trying to swap the Other Way. I will admit it is a Pain to Adjust 4 Idle Mixture Needles, and the Fixed Jets eliminated that, but if you boated higher than Sea Level, the Idle Mix was too Rich, and often made for a Cantankerous Motor.

 

[racerone]

Running / idling issues with your 55 year old motor ?

 

[68glasspar]

In the Mid 70 and 80s, a lot of Owners were trying to swap the Other Way. I will admit it is a Pain to Adjust 4 Idle Mixture Needles, and the Fixed Jets eliminated that, but if you boated higher than Sea Level, the Idle Mix was too Rich, and often made for a Cantankerous Motor.

Elevation here in wisconsin is under 1000ft

 

[racerone]

Go ahead and install a set of fixed jet carburetors off say a 73 to 77 model 85 HP.

 

[68glasspar]

Running / idling issues with your 55 year old motor ?

Mid range and idle are rough, WOT is very good though. I previously had a sticky timer base due me misrouting one of the points wires. And i put in new L20V spark plugs. The original manual says L19V plugs.
I will recheck compressions today.

 

[68glasspar]

Go ahead and install a set of fixed jet carburetors off say a 73 to 77 model 85 HP

Any thoughts on whats the best spark plug for this engine?

 

[racerone]

depends on the condition of the motor.----Is thermostat working properly?----What do you do with this motor / boat.

 

[68glasspar]

depends on the condition of the motor.----Is thermostat working properly?----What do you do with this motor / boat.

The high temp light has never come on, but it hasn't been run long enough on the lake without one problem or another to really know. I plan on just using it for cruising around my lake. mostly mid range or idling during no wake periods

 

[68glasspar]

Compressions are 120-120-115-118