Power pack symptoms?

[Joe Reeves]

Re: Power pack symptoms?

DK.... The "L" in your model number simply indicates that the engine is a "Long" shaft model, ignore the "L" and apply the rest of the model number as per my previous post. As Hooty states, a inline fuel filter takes care of any possible sediment problems. The high speed jet fouling problem is 99.9% of the time caused by having the engine sit for long lengths of time. The other 1% is due to problems such as deteriorating fuel lines, etc. The tube leading from the bottom of the carb up into the venturi (throat) is called a nozzle.... mainly the high speed nozzle. Good Luck........

 

[dennisknight]

Re: Power pack symptoms?

Ok, the carb is cleaned and reinstalled. Seems to run much better, but can't run WOT in a garbage can, will try on lake tomorrow. Still won't run on just the top cylinder at low idle and have tried swapping coils. It does run on top only if I open it just a bit. Some other observations and dumb questions: There are two exhaust ports in back center of exhaust housing that spit exhaust and water when in neutral, but only spit exhaust when in gear. Does this sound right? Also, the one on the right (starboard side) spits a little stronger than the one on the left, not much, maybe 20% more. Does this mean anything?

 

[dennisknight]

Re: Power pack symptoms?

Hooty, thanks for the idea. I think I'll buy a small one and install it right inline on the feed to the carb. Joe, thanks for your tutorials. I'll let you know how it runs tomorrow.

 

[dennisknight]

Re: Power pack symptoms?

Hats off to Joe Reeves! It's going as fast as it ever has (27mph pushing a 16' Sea Mymph aluminum hull). Thanks so much for all your help. Glad I didn't buy a new power pack now. Can you comment on my last questions about the running on one cylinder and exhaust concerns. Any ideas or am I just getting paranoid?

 

[Joe Reeves]

Re: Power pack symptoms?

DK..... Dropping one (top) cyl at an idle (if you have proper spark) would most likely be that the idle adjustment (top needle valve) is set slightly too lean. Proper adjustment follows:<br /><br />(Carburetor Adjustment - Single S/S Adjustable Needle Valve)<br /><br />Initial setting is: Slow speed = seat gently, then open 1-1/2 turns.<br /><br />Start engine and set the rpms to where it just stays running. In segments of 1/8 turns, start to turn the S/S needle valve in. Wait a few seconds for the engine to respond. As you turn the valve in, the rpms will increase. Lower the rpms again to where the engine will just stay running. Eventually you'll hit the point where the engine wants to die out or it will spit back (sounds like a mild backfire). At that point, back out the valve 1/4 turn. Within that 1/4 turn, you'll find the smoothest slow speed setting. <br /><br />When you have finished the above adjustment, you will have no reason to move them again unless the carburetor fouls/gums up from sitting, in which case you would be required to remove, clean, and rebuild the carburetor anyway.<br />---------<br /><br />The two exhaust ports you mention.... Inside that long exhaust housing is another tube (housing). Between the outer and inner tube is water, otherwise that external housing would get so hot, it would be quite dangerous. Those two exhaust ports are actually relief ports. The purpose of which is to allow excess water to escape. You'll note that when you slow the boat down, quite often the water will come boiling up on the surface towards the stern. At the same time, it is racing up towards the boat under the surface. If those two holes (ports) weren't there, the water would enter the prop exhaust section, travel up the exhaust tube and enter the piston area via the cylinder exhaust ports.