rpms are down by 400 , why?

mbb

Petty Officer 2nd Class
Joined
Apr 20, 2001
Messages
176
changed stator and replaced a cracked plastic float chamber on my 112 johnson with metal float chamber. New jets in the metal chamber, but they are the same size as before. (.067 high, .025 intermediate). The motor now runs good, Ive put about 60 miles on it in two trips but tops out at 400 rpm less than before (4400, and thats too low), takes 5mph off top end too by gps, so its not a bad tach reading. I did change the fuel pump too.<br /><br />Any ideas why? Yes I synched the carb linkage, Ive cleaned carbs and adjusted linkage several times before so Im sure its correct.<br /><br />Pickup timing is fine, Changing stator shouldnt change the max advanced timing, but I cant check that anyway. Any ideas before I take the carbs apart and examine? (was done only 3 months ago anyway and everything was fine till I changed thet stator and float chamber.)
 

Terry H

Lieutenant Commander
Joined
Sep 25, 2001
Messages
1,862
Re: rpms are down by 400 , why?

sounds like you are running on 3 cylinders...do a spark test...just a thought :)
 

mbb

Petty Officer 2nd Class
Joined
Apr 20, 2001
Messages
176
Re: rpms are down by 400 , why?

Originally posted by Chief 101:<br /> sounds like you are running on 3 cylinders...do a spark test...just a thought :)
Im sure its 4. 3 would be a big power loss, and there really isnt any. It runs great with good power and acceleration, just tops out 400 rpm lower than it used to. Ive run on 3 before when accidentally left spark boot off, that is evident.
 

mbb

Petty Officer 2nd Class
Joined
Apr 20, 2001
Messages
176
Re: rpms are down by 400 , why?

I pulled the carbs. One had a small piece of trash in one of the high speed jets. dont know how, I use air and blow everything out and keep everything clean when putting together, but it was there. Everything is back together and hopefully great.
 
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