replace main jet or try "sea foam:?

[scottandrea]

hi. i have cleaned and cleand the carb on my '94 9.9hp jhonson and i can see a good spray of gas at wot but it still lacks about 500 rpm unless i tap the primer button about once every 5 seconds. the motor runs awsome except for this and a very slight ping noise at mid throttle. once in a great while it will start to recover its full rpms only to lag a bit. the motor is adjusted good,starts first try,and will idle for hours. any thaughts?????

 

[HighTrim]

Re: replace main jet or try "sea foam:?

It does sound like its starved for fuel. If you do decide to decarb with seafoam (which I dont think is your problem by the way, but im no expert by any means) try this.

In a portable tank, mix 3/4 gallons of premix gas, an 3/4 can of seafoam, (assuming you don't have the vro connected). Put the remaining seafoam in a spray bottle, run the motor up to temperture, remove the plugs, one at a time, spray some seafoam into each cylinder and replace plug. let sit 15 minutes, remove the air silencer from the carb while waiting, restart motor, and spray seafoam into each carb, until it start to stall. repeat till seafoam is gone. run out the rest of the gas. it is going to smoke like it is on fire, and drip goo on the ground. replace the plugs with new ones, and then do the compression check again. this procedure burns the carbon out of the motor and been known to free up rings, and increase compression. let me know the results.

 

[tashasdaddy]

Re: replace main jet or try "sea foam:?

HighTrim, glad to see someone reads my post. good quote.

i don't think that is the problem either. i think link n sinc is out a little. or there is a minor obstruction in the high speed jet, which the seafoam may clear.

 

[scottandrea]

Re: replace main jet or try "sea foam:?

is there a place to view "linc n sinc" online?

 

[scottandrea]

Re: replace main jet or try "sea foam:?

hey if the timing was off a bit wold the xtra squirt of gas from the primer give me my lost rpms? cause i know the throttle cam adjust is perfect.............

 

[tashasdaddy]

Re: replace main jet or try "sea foam:?

sorry no, they are specific to each individual model and HP. the best direction are in the OEM manuals. outboardbooks.com