69 Evinrude 40hp Lark

"Model: 40973R

I would like

"Model: 40973R

I would like to get some prices for 11 - 13 pitch props for my Lark 40. Graham Lamb ran some numbers for me last year(thanks) but I never got the chance to buy anything before the Wisconsin winter kicked in. Who stocks OE style older Evinrude props? I ran into a bunch of walls trying to search locally due to the age of my outboard. My current prop has slipped a couple times and I have no useable spares (the previous owner must have been slightly blind because I found 3 bent up, dog-earred props in a stowage compartment). The few times it slipped, I backed off the throttle and punched neutral then forward on the selectric shift with no problems but the problem repeated at plane at just under WOT once more in the season. The only prop I have is in so-so shape but still gets me up on plane without vibration. Also, I seem to be missing what is called a 'thrust washer'. What does this do? Is this possibly the reason for slipping? Or am way off course? How do I find one of them regardless? My old OE manuals make an important note that I should have one, it just doesn't explain exactly why. I assume I am losing thrust somehow? Any help will be appreciated."

Is the belt driven generator w

Is the belt driven generator working? It must work in order for this motor to stay in gear properly.

"I haven't had any chargin

"I haven't had any charging problems, I run nav and search lights and have a key start and my battery has never dropped below 12v - even when stored over winter. The gen belt is great shape and tensioned correctly. From what I understand, the gear engagement (forward or reverse) is held in place by electro-magnetism - could it lose engagement from a momentary loss in the generator harness? Or is the gear circuit running off battery supplemented power?
The slipping happened only 6 times in 40 hours of operation - I just assumed it was hub slippage due to the age of my current prop."

"Guess what, I just learnt my

"Guess what, I just learnt my Evinrude 40 hp Lark uses a shear pin drive so there can't be hub slippage (the pin is intact). So with the generator in good shape I'm still at a loss as to why it has kicked out of gear and over revved on me. Sorry I'm a slow learner, but I'm brand new to old boat motors and any help would be great.
Note: Has anyone heard anything good about the 'prop doctors' out of Kansas? I found my prop options on their website and might try them out."

"Yes there can be hub slippage

"Yes there can be hub slippage!----- the prop on your motor is not a one piece item--- it is a brass / bronze hub with rubber bonded to it, This is then pressed into the aluminium outer part.The pin should be steel and is not supposed to shear."

Hey thanks - I would never had

Hey thanks - I would never had known by just looking at it.
While I'm waiting to get a new prop - my procedure for immediately dropping revs and selecting neutral than forward seems to work - is this going to be okay but why do you think it re-engages? Do you think I could damage the drive doing this? I am dropping revs to the desired shift range.

Check your lower unit for wate

Check your lower unit for water in the oil! If a new prop fixes the problem great--- if not you have a problem with the clutch spring and clutch hub---If you then continue to operate you could be looking for an honest mechanic who really understands the electric shift and knows the simple repair for this--failing that a good used lower unit.New parts are super expensive as per ' shop.evinrude.com "

"I haven't seen water in t

"I haven't seen water in the oil yet. I changed the oil out when I bought it and have changed it out again as one of the things for winterizing in Nov 07.
Next item while waiting for a new prop is figuring how to set up a tachometer so I can check for correct rpm during WOT. I guess if I am going to be messing around with pitch options - I should know what my engine is achieving currently. Do you know of any examples of basic wiring diagrams (for dummies)on the web for generic aftermarket tachometers? My OE service manual has an electrical diagram that shows an available ground connection which eventually ends at the cut-out switch mounting screw. The diag doesn't show the other end of the harness, just shows a symbol labelled tachometer ground lead."