76 Evinrude 4HP carb adjustment.

[DDP7]

1976 Evinrude 4hp mdl# 4606M

Looking for a little guidance on making adjustments to carb. I have read several forms on this motor and tunning or clean carb. I know where to start and a little of the process. Just had some questions and hopefully someone could answer them.

1. Once I have removed knobs and gently bottomed out the low and high speed and made my back out turns. Which I find 1.5 for low and .5 for high. Should I reinstall knobs at this time. Or leave them off until adjustments are made.

2. When adjusting high speed is it best to do this under load?

Brief on motor. Starts great, sounds great, when in large trash can of water running at full throttle it sound great. Sounds wide open and top power. But under load (14' Jon with 200lb person) sounds the same but only moving maybe 5-10 mph. I know its only 4hp but I am not getting plane. I have seen a couple videos on this motor with same size boat. I am not achieving any thing close to what I have seen on this motors top speed.
Any help would be great. Plan on working on it today. Am I heading to the lake or playing in a trash can full of water?

 

[Vic.S]

Before you adjust be sure the carb is clean and that the adjusting screws are tight in their packing washers

Pull the knobs off and make the adjustments with a screwdriver ( the ends of the adjusting screws are slotted)

After adjustment refit the knobs in the centre of their range of movement.

High speed adjustment should be done at wot under load ( Initial setting ITYWF is 1 turn out). Good fun in small boat... take care.

See the full details in Joe Reeves Instructions on the Engine FAQs board. http://forums.iboats.com/forum/engi...nts-for-asorted-carb-variations-by-joe-reeves

There is also a link from the "Top Secret File"

While you are there, look at the FAQs board index for other useful topics.

 

[lindy46]

Not sure exactly how those carbs are set up, but I usually put the knobs on backwards so the stops don't limit movement, until I get everything adjusted properly. Then I turn them around into the proper configuration. Final adjustments must be done under load on the lake. First adjust the low speed for optimum trolling. Then run her a WOT and adjust the high speed for optimum RPM's/speed. That size boat isn't going to plane with a 4hp motor.