love my big twin!

[pcrussell50]

rds21b 1959 super seahorse 35hp

sure, she has a confounding stumble at idle, but she starts every time, and if she doesn't, it's easy to figure out why. and the stumble smooths out with a little extra power.*

today i found out my fancy oil-injected yamaha on my fancy boston whaler, won't crank.

looks like i'll be boating in my '59 span america runabout, with the '59 super seahorse again while the newer stuff is down for repairs.

*i was thinking of replacing the carb needle packing

what else could cause it to be stumbly at idle and smooth under power?

-peter

 

[tashasdaddy]

Re: love my big twin!

low speed mixture, adjust it 1/8 turn and wait 15 seconds.

 

[jbjennings]

Re: love my big twin!

If not what TD said (most likely, or vacuum leak), possibly compression a tad bit low.
Later,
JBJ​

 

[pcrussell50]

Re: love my big twin!

low speed mixture, adjust it 1/8 turn and wait 15 seconds.

i'll try it some more, but i posted to this effect back in june. it has persisted through several low-speed needle settings. i was thinking of removing the needle and looking at it, but i don't know if that AUTOMATICALLY ruins the packing. IOW, do you have to replace the packing every time you remove the needle?

what are the symptoms of a worn low speed needle?

-peter

 

[Daviet]

Re: love my big twin!

You do not have to replace the packing every time you remove the needle, you might have to tighten up the packing nut a bit.When the needle is worn the low speed adjustment will be hard to adjust properly.

 

[pathfinderz1]

Re: love my big twin!

Take the low speed needle out and check for ware on the tip. If it is you can dress it up by putting it in a drill press and take a fine file vary gently dress it till the ware doesn't show and it will be like new.
Mike aka pathfinderz1

 

[asdasc]

Re: love my big twin!

what a great idea. I hadn't thought of doing that. It is just a straight taper to a fine point, right? Is there any problem with making it too sharp?