2000 M70C Carb Sync?

scubayachts

Cadet
Joined
Jul 11, 2006
Messages
20
I am going to do a carb sync this weekend after I pull and clean the carbs. In the shop manual, it states:
"The boat and engine must be in the water under normal operation conditions. The boat cannot be tied to a trailer or dock and must be free to move"
What does this mean? Does it mean you go and have some one bump the boat into gear and drive around the canals while I adjust the pilot screws?

Also, when adjusting the pilot screws do I do the 1-3/8 turn to each pilot screw before I move down to the next one or do I do 1/4 turns on each until I get to 1-3/8+-1/4?
What does the manual mean " adjust each pilot screw to find the setting at which engine speed increases" When I get to a certain point of counter clockwise turning does the rpms start to drop again?

Any help and explanations you can give will be greatly appreciated!

This will be my first carb removal and cleaning. Any suggestions. The manual says do not do a carb dip but reading some of your posts, some of you say to do a 2-4 hr dip?

Thank you!
 

Sea Rider

Supreme Mariner
Joined
Sep 20, 2008
Messages
12,345
Re: 2000 M70C Carb Sync?

Not an expert or a multicarb engine lover, prior to any adjustment, boat must be on water and engine must be warm, TG or Pvanv should provide proper tech answer. If each carb has a vacuum port would be fantastic to tune with 3 vacuum gauges, one for each carb while engine is on for top of the line adjustment. It's near a science and have to be very ear skilled to hear good music while adjunting each carb individually... Clockwise should speed up, CC should speed down.

Happy Boating
 

scubayachts

Cadet
Joined
Jul 11, 2006
Messages
20
Re: 2000 M70C Carb Sync?

I don't believe the carbs have a vacuum port, but I could be wrong. Thanks for your response and Ill wait and see what TG or Pvanv says. Thanks!
 

pvanv

Admiral
Joined
Apr 20, 2008
Messages
6,573
Re: 2000 M70C Carb Sync?

Follow the procedure in the Factory service manual. Start with equal settings on the pilot screws.
 

scubayachts

Cadet
Joined
Jul 11, 2006
Messages
20
Re: 2000 M70C Carb Sync?

does the boat need to be in the water and in gear while doing the carb sync or just in the water idling? The manual does not specify. Thanks!
 

Sea Rider

Supreme Mariner
Joined
Sep 20, 2008
Messages
12,345
Re: 2000 M70C Carb Sync?

Adjust 3 pilot screws as suggested, place engine/boat on water, leg on bucket, muffs, warm engine and check at idle while engine is at neutral.
 
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