Any one know of a site that will tell me what parts will interchange with
I have a great running 8HP with a tapered output shaft.
I want to use it to replace a tired 7HP that has a key shaft.
So I have to replace the existing tapered shaft in the 8HP with a keyed
shaft that matches the 7HP.
Changing the cranks is no problem. Finding the correct crank, for the
replacement, is proving difficult.
The older, (valve in block), 7 and 8 HP B&S engines are very similar. I
think the stroke was the same, but the bore was different. (maybe the other
way around??) The crankshaft should swap over, but you may need to swap
connecting rod and piston too.
I forget if it was the bore or the stroke that was different, but I do know
you should be able to do the swap with the parts from each engine.
I have a manual around somewhere so I could get more specific if you want me
Thanks for the quick reply.
If the strokes are the same I am good to go.
I could just order a new crank for the model/type 7HP and put it in the 8?
Is there a listing of what cranks were used in what engine.
8HP is model 190412 type 3129
7HP is model 170452 type 2351 (this has a gear reduction unit that I will
remove and rebolt to the 8HP)
Ok, I got out my manual.
Bore is the same on the two models you have, so that makes the crank
different, and I checked, the pistons are the same, the connecting rod is
Yes, but you will have to move the side cover for the gear reduction to the
other engine too.
If I understand you correctly, the 7HP has a gear reduction box and you
would like to remove the gear reduction, side cover, and crankshaft and
install it on the 8HP engine. No problems so far, but you will need to use
the 7HP connecting rod too. The 7HP and 8HP block should be identical, the
only possible problem I can think of is if one of the two engines has a ball
bearing crankshaft on the flywheel end, but the other is plain bearing! I
believe that both engines has plain bearings on the flywheel end.
The side cover for the gear reduction needs to stay with the reduction unit
as it is different from most other variations.
The only other question I have is are both engines aluminum bore? Some were
aluminum block with a cast iron sleeve so you need to use the correct
piston, don't mix them up!
Yep, but there is a butt load of them and only a very knowledgeable parts
man would know what fits what. Bearings, side covers plus some other
variations complicate things!
(E-mail is good if you waant to go off line.)
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