Logo
FULL SITE MENU

1961 RDS-23 won't run

T

tsteelman

Member
Ready to run up the white flag. Motor acts like it wants to start, but will only occasionally backfire. New coils (green), points, condensers, plug wires, and plugs. Points gapped at 0.020. Spun the engine with plugs out and both are getting spark. Cleaned and rebuilt carb and new fuel pump diaphragm. Good fuel flow to float bowl, primer bulb nice and firm. New head gasket, bolts torqued to 15 ft/lbs. New impeller and seals. Replaced leaking power head base gasket and the inner exhaust housing was loose. Tightened it up with a new gasket and lower seal as the old ones were trashed. Any ideas on what could be the problem?
 
Points must be set when the flywheel key is perfectly aligned with the fiber rubbing portion of the points. Set the points so that a .020 gauge will pass thru BUT a .022 will not.

The vertical metal portion of the coils must be aligned with the top inside bevel of the aluminum seat upon which they sit. (small bevel but it's there... look for it).

The flywheel nut MUST be torqued to 105 foot pounds otherwise the key will shear, effectively throwing the engine out of time.

Let us know what you find.
 
The backfiring sure sounds like a possible sheared flywheel key, doesn't it?
In addition to the proper torque, the shaft must be perfectly clean and dry before installing the flywheel.
 
Thanks for all of the responses. Points gapped properly. Coils flush with the bevels. flywheel torqued to 105 ft/lbs. Wires run properly. Notice flywheel isn't going all the way down. The flange on the flywheel is not sitting all the way down inside the groove on the armature plate. Needs another 1/4 inch to sit all the way down.
 
The flywheel NOT sitting down properly indicates that possibly you are using a woodruff key from a hardware shop instead of the more expensive factory key (#307480 - $4 or $5) for that 1961 40hp Johnson. If this is the case, toss that off brand key and purchase the proper one as you CANNOT substitute that special key.

Also, the outer straight edge of the key must be vertical with the engine... NOT aligned with the crankshaft taper.
CS-FW_Key_Align.jpg
 
Hey guys. I am using a factory woodruff key I bought from Marine Engine. I use a three bolt puller to remove the flywheel. The key I got from Marine Engine has two marks on the side.
 
tsteelman said:
Hey guys. I am using a factory woodruff key I bought from Marine Engine. I use a three bolt puller to remove the flywheel. The key I got from Marine Engine has two marks on the side.
Click to expand...

Okay, that's proper... good for you to be going by the book. Flywheel key the proper number.... 307480?

Obviously we aren't there to visualize what's keeping that flywheel 1/4" from seating properly. What have you found that's interfering with it?
 
Removed the armature plate to get a better look at the bottom of the flywheel where it rests on the crankshaft. The flywheel won't go any further due to the taper of the crankshaft with or without the key installed. So I am assuming the top of the flywheel is not supposed to be flush where the threads end?
 
If the top of the flywheel was flush where the threads end, it would be impossible to torque (105' lbs) the flywheel nut as it would have run out of threads.
 
Makes sense joereeves. Buttoned up everything, 105 ft/lbs torque on flywheel. Spun engine with plugs out. Big, fat spark on each plug. Still won't start. Needless to say, I am completely stumped. At least it isn't backfiring when I pull on the starter rope.
 
kimcrwbr1, I tried that this morning. Pulled plugs and they are bone dry. Removed carb, manifold, and reed valves thinking the carb wasn't delivering fuel. Backside of the reed valves were wet with fuel. Each reed is sitting flush on their respective seats. Any ideas on what could be going on?
 
Back
Top