1970 25hp johnson runs great with hood off put hood on chokes motor out

Chinewalker

Fleet Admiral
Joined
Aug 19, 2001
Messages
8,902
More often than not, that means you've got an exhaust leak. Check the base gasket and exhaust cover gaskets for evidence of blow-out (oily residue).

Occasionally, it may point to a spark plug lead being pinched to the belly pan and shorting out.
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
36,297
So is this with the motor running in a barrel ??????-----Do you have a fan to blow the exhaust away ??
 

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,195
That was my immediate thought also. Running in a barrel? Get it out of that barrel and on a boat, on the lake, where it was designed to run. Then report back if you still have trouble.
 

snostuddd

Recruit
Joined
Jul 27, 2015
Messages
4
I have run my other motors in barrel and had no problem with them choking out. I will test today at a close lake thanks.
 
Top