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Tohatsu M50C- New Prop has slack....

M

MarkNY

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i recently purchased a solas amita 3 blade prop for my early 90's M50C... there is about a 1/4" of slack in prop fore and aft. is this acceptable? if not, how do i fix it? thanks alot, mark
 
The prop must seat solidly on the prop shaft. It is normal for the shaft to have some fore/aft play. Is the prop seated on the shaft?
 
Hi Paul, the prop fits properly on shaft. 13 spline. First there is the thrust washer, then prop, then a plastic washer with brass ring that matches the spline, then a thick metal washer, then nut. When I push prop all the way down and tighten nut all the way there is approx a 1/4" gap... Hope that explains the setup. Appreciate any advice. Mark
 
Something's not right. Perhaps the prop is not the right dimension -- maybe for a different motor? If you assemble the thrust bushing and the stopper to the prop, and then the washer, the nut should come all the way down and snug everything together. What specific Solas unit did you get?

The same prop should interchange for the 2-cylinder C models and the 3-cylinder D models, as well as the modern TLDI motors.
 
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It's the 3 blade 11.63 dia x 11" pitch SR. Part # 5311-116-11 on iboats... Specifically for the M50C according to website. Hope that helps... Best, mark
 
If you have the old prop (which i presume fit correctly), compare the dimensions of the center splined "tube" between the 2 props. There is a possibility you got the wrong prop.
 
according to solas i have the right prop. i also talked to a tech at tohatsu but that wasnt very helpful. the prop seats onto the shaft and fits behind the thrust washer properly. the recessed edge on the front of the prop lines up with the gearcase. the space i have is on the splined part of the shaft behind the prop but before the threaded part of the shaft. when i install a stopper(plastic ring with brass inner ring that is splined) i have approx 1/4" gap between the next part which is a ss washer with the nut behind it. thats 1/4" gap with the nut tightened all the way down. i thought if i put another stopper on behind the other that would fill gap. any suggestions? thanks, mark
 
Clearly the prop isn't fitting correctly; Did the old prop fit properly? Is the length of the hub of both props the same? Either the prop, thrust washer, or stopper is a different dimension than what is needed. Yes, if the prop is properly seated, and has proper clearance to the housing, then the thrust washer is probably correct for the prop and LU, so the difference is likely either the prop or the spacer. You could "fill" the gap with another or different stopper (or a couple of washers), but that would be compensating for whatever dimension is wrong.
 
Paul, I found a different stopper and that filled the gap perfectly. Ran boat today and it worked great. Thanks for your help...
 
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