Odd question about an Evinrude Carb

TinBoats.net

Help Support TinBoats.net:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

catmansteve

Well-known member
Joined
Apr 18, 2012
Messages
196
Reaction score
0
Location
Berkeley Springs, WV
I've got a 66 Fastwin 18hp and just got finished rebuilding the carb. I noticed something funny; the instructions in the rebuild kit showed a low speed needle up top going into the carb body, and a high speed needle down below going into the bowl. Mine has the low speed needle, controlled by the idle knob next to the choke lever, but where the high speed needle "should" be, there's simply an aluminum machine screw, no bushing or anything.

The motor runs great, fast throttle response, revs good, doesn't smoke much (a little but I attribute that to running 40:1 mix)... So what's the deal with the screw? Did it come from the factory like this or did someone pull the bushing and needle out and plug the hole? If this is the case, why, and how does it not run seriously rich?

Not that any of this matters, the motor runs great, I'm just curious. Can anyone shed some light on this?
 
Well............when you did your carb job you apparently didnt pull the high speed jet (that is behind that screw you want to know about) out of the fuel bowl or even take that screw loose to see what was behind it?!
Had you done that you would have known that the high speed circuit in that engine is controlled by the fixed high speed jet in place of the adjustable needle. Carb kits will very often fit several different models of carburetors.
When doing a carb job it is always best to completely disassemble and thoroughly clean each passageway and orifice. Glad yours is running well !
 
Please forgive my lack of knowledge on the subject, this was my first carb rebuild. I started to take the screw out, but it felt like the head was going to snap off so I thought it best to leave it be. Thanks for the insight, I will know next time
 
Hey, not to worry....your first carb job turned out better than alot of folks on here! There is a current post on an 8hp that the fellow has gone into his carb twice so far and according to where the needle is running.....still doesnt have it clean!
 

Latest posts

Top