Big 4 h.p.

tyleryamaha

Active Member
#1
Does anybody know if the side engine cover on a big 4 h.p. will interchange with a 5 h.p. cover. mine has a extra shaft that I want to eliminate. Thanks
 

Motra

Active Member
#2
It probably will as long as the crank is the same size where it comes through the cover. The extra shaft is an extension of the cam so you'd either have to use the 4HP cam, which might be different, or cut down the 5HP cam very precicely.
 
#5
Ok since we are on the subject of the extra length of the cam shaft.....

it is for reverse on the tillers. Which in my opinion are dangerous. Just inmagine if you will..........tilling away at the garden wether it be a flower garden or a vegitable garden. Most folks around here put up little fences to keep varmits out, which dont help much, and you decide to use reverse.... You are tilling back wards at full speed and the engagement lever gets stuck, you trip over the little fence and the tiller runs you over..............Then you look like me with no legs................that is why I wont hook reverse up on a tiller.

Now back to your story.....

Just cut off the end, flush with the sump cover. it dont need a special plug or any thing and dont go tearing it apart to change the cam. Cause then you will need a pan gasket because if it hasnt been changed in for ever.... it will break on you. But it is your stuff do what you will. Just my 2 cents.
 

delray

Well-Known Member
#6
yes you could just cut it off? pluging it would be one less thing to link oil out if seal gets old. if you do have the option to look for a different side covers? you may want to look for one with the 4 bolt holes. this will allow you to bolt a torque converter or bolt on jackshaft. also make sure it has front oil fill plug if you use this type of side cover.
here is couple different side covers with this option:thumbsup:



 
#7
yes you could just cut it off? pluging it would be one less thing to link oil out if seal gets old. if you do have the option to look for a different side covers? you may want to look for one with the 4 bolt holes. this will allow you to bolt a torque converter or bolt on jackshaft. also make sure it has front oil fill plug if you use this type of side cover.
here is couple different side covers with this option:thumbsup:



if you dont mind me asking what were those engines off of???? I know they are briggs but I havent seen one with the gear or the threaded pto shaft.
 
#8
I wouldn't go through all the trouble, just cut the reverse shaft flush with a hack saw or sawsall and clean up the end with a sander then change the oil and clean the gasket. It won't even be seen with a chain guard and looks cool spinning backwards anyway.

This 5HP is one of my kids favorite engines and the most ridden, it's been a GREAT engine for a few years now and is now a permanent fixture on his Bonanza (which both needs paint). Best $20 we've ever spent,, We've had zero problems with it and no leaks.

 
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#11
I remember a lot of cheapo snowblowers and old Craftsman reel-type mowers (4HP) had the planetary, internal gear reduction units. They can still be found in metal scrap yards, flea markets, and at the curb on trash nites! The 4HP mtors have a better connecting rod, lighter piston.
 
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