play in prop

[jimlad]

d i have a mariner air cooled 3.5hp i have slight play with the shear pin in the prop shaft is this normal or should it be quite a tight fit

jimlad

 

[Silvertip]

Re: play in prop

Check the holes in the prop shaft and the prop hub for elongation. Some looseness is normal but if the holes show elongation, acceleration and deceleration forces can start a rocking motion that will eventually shear the pin. That said, I doubt it will be a problem with 3.5 HP.

 

[jimlad]

Re: play in prop

well when i bought the motor second hand the shear pin was broken so i had to try and find a new one but i think the one i purchased seems to small but was told it was for this motor on the packet i bought the pins in it says they are tohatsu parts they are silver in colour but the one i took out that was broken looks a coppery colour and is thicker than the new one i got,the hole that the shear pin goes into one side does seem slightly bigger than the other side what could i do.

many thanks for help

jimlad

 

[Silvertip]

Re: play in prop

To check the diameter of the hole in the drive shaft, get out your set of drill bits and the one that fits the tightest is the hole size. Next time you visit a hardware or farm store, check in the tools area for bronze (copper colored) brazing rod (uncoated welding rod) in the size that's closest to or exactly the same size as the drill bit you used to gauge the hole. You can now use a hacksaw to cut as many shear pins as you like. The key here is to get as tight a fit as possible. One rod should give you a dozen pins and will cost a few cents (but you may have to buy more than one rod). Failing that, a local machine shop shoud be able to drill a new hole in the drive shaft 90 degrees from the existing hole. The motor is light and would not need to be disassembled.

 

[jimlad]

Re: play in prop

8) 8) thank you very much for that idea i will get some rods and do that, i am all for saving a bit money where you can
you have saved the day i was getting worried that i couldnt get the correct size pin
many thanks againd d