Link & synch advice for 2000 model 90hp Merc

[Bob Kimber]

Just checking if my procedure to adjust throttle arm cam and roller is correct with this newer model compared to previous models<br /><br />To adjust throttle cam after first checking carb linkage to confirm carb butterflies are fully closed.<br /><br /># With throttle control in neutral position loosen cam roller screw.<br /><br /># Hold throttle arm to ensure idle stop screw is against its stop and move cam roller to touch throttle arm cam, check that indicator mark on throttle arm aligns with mark on middle of cam roller. Adjust if neccessary with idle stop screw to align marks.<br /><br /># Tighten lock nut on idle stop screw when alignment is correct.<br /><br /># With engine in neutral and throttle arm in idle position adjust clearance between cam roller and throttle arm cam to spec (this model .005 to .020)when clearance is correct tighten cam roller screw.<br /><br /># Check wide open throttle setting and adjust throttle stop screw if neccessary to provide correct opening of carb butterflies.<br /><br />thanks for any advice<br />Bob

 

[graddy]

Re: Link & synch advice for 2000 model 90hp Merc

Bob, I posted the procedure to set the carbs for a good idle last week or so do a seach. FYI try to set the cam .005 or less but still turning freely.

 

[Bob Kimber]

Re: Link & synch advice for 2000 model 90hp Merc

Hi DTS<br /><br />I have just read your post and it is the same setting as I have previously adjusted carbs, I notice in the older manuals they said all the mixture screw settings are the same, Have they changed the carbs much? I notice that the new carbs don't have the back drag jet, just the threaded hole where they used to be beside mixture screws. <br /><br />I just wanted to be sure my procedure for adjusting cam roller was correct as it has been set incorrectly by someone else previously. My motor starts first turn of the key and runs well, but I felt there was a bit of a lag when opening throttle, current clearance on roller is about 1/8".<br /><br />Thanks for your advice<br /> Bob

 

[graddy]

Re: Link & synch advice for 2000 model 90hp Merc

One more thing to remember is to do all adjustment with the lower unit submerged in the water, back presure on the exhaust is important. Trying to set the carbs on a flushing attachment will not give you good results.

 

[Bob Kimber]

Re: Link & synch advice for 2000 model 90hp Merc

DTS<br />I have always set up and run my motors in a drum as I don't trust the flushing units, and then do final adjustments on the water. I usually find I have to richen mixture very slightly on the water for best running as I think there is greater backpressure with the engine at proper depth in the water<br />Thanks again for your time<br />Bob