1987 force 15hp lower unit help

[Guest]

Question: I changed my impeller but for some reason one of the bolts does not tighten up. I looked at the thread and it looked fine. can the thread inside the unit itself be stripped and if it can how can I repair it without buying a new lower unit.

 

[scottmm73]

Re: 1987 force 15hp lower unit help

The thread on the bolt may be fine, however the thread in the lower unit may be stripped. You can purchase a "helicoil insert kit" from any auto parts store. Just search what is in quotes.

 

[Frank Acampora]

Re: 1987 force 15hp lower unit help

Those are 1/4 X 20 bolts. usually they only go into the lower unit casting about 1/4 to 3/8 inch. Look closely: If there is no interference, the bolt hole can be drilled deeper and tapped for a longer bolt. Use some RTV silicone seal on the bolts to prevent corrosion of the casting and don't tighten them too much. 70 inch pounds is MAX and you can easily exceed that by hand. Too much torque can warp the pump too. Tighten them to the point where they will not back out and the pump body seals against the plate.

 

[Guest]

Re: 1987 force 15hp lower unit help

The thread on the bolt may be fine, however the thread in the lower unit may be stripped. You can purchase a "helicoil insert kit" from any auto parts store. Just search what is in quotes.

does it go by bolt sizes?

 

[Guest]

Re: 1987 force 15hp lower unit help

I been trying to find a diagram with bolt size but cannot find one

 

[scottmm73]

Re: 1987 force 15hp lower unit help

Here is one from Napa

 

[maytheforcebewithus]

Re: 1987 force 15hp lower unit help

Someone once recommended this product to me instead of using a helicoil, check it out I prefer this for thread repair whenever possible...

https://www.google.com/url?sa=t&sou...cc4vD1kJdzTixKkaN_2Su5g&bvm=bv.48572450,d.dmg