OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions On Briggs & Stratton Engines 130902 swap shaft

Hi--
I'm new here... I've been learning motors lately out of necessity. Mostly two-stroke chainsaws... Have those in check! Then my log splitter broke. I don't want to buy a new one so decided to work on it. Got quite a ways and have now entered new territory.

I have a 130902-1015 (pic attached) that I've uninstalled from the splitter's pump. I recently bought a brand new 130902-0016 (attached pic)that I hoped would be identical, but isn't--the shaft differs from the '1015'. Before I remove the shaft casing I figured it would be wise to ask folks here if there are any gotchas... With chainsaw I would have to split the case using "case-splitter" tool. I'd also want a new gasket on hand prior to doing this type of work... With the 130902 finding another gasket concerns me and I may use liquid gasket. But I really don't know what's in the case (I expect there is a seal around the shaft that may be delicate/irreplaceable?) Figured someone here can share concerns, or have ideas before I do something stupid with a new motor.

Thanks.

Hi JL43062,
Welcome here,
What I have to ask is what is the problem, shaft length. If that is the case there is no way in hell that you would consider swapping the crank over, really bad idea. If the shaft is the issue, just cut the crank to the length you need and using a dremmel cut a new keyway

Hi Norm--thanks for the welcome. I appreciate the ideas/response!
I'm realizing I didn't focus on the shaft details enough... Sorry for this. I attached a couple more pictures in this post. Attached '0052' displays shaft I'm attempting to fit pump to. '0054' is the new motor shaft. They're very different shafts.

Length is greater on the new motor shaft. The new shaft also has an indented notch... The old shaft has a key that protrudes. Hopefully the pictures do better at explaining details as I don't know the terms well. To me, it looks like the shaft diameter comes out of the case the same diameter (haven't measured this yet to confirm), but is is milled completely different. I have no experience cutting shafts, but cutting everything around the key seems like a lot of dremel work. This is why I was considering the next steps of swapping shafts... They're basically the same motor except shaft. Bummer if this isn't an option.

I suppose I can hunt down a pump that fits the new shaft? Or, just work on the broken motor... Piston is seized on old one. Likely can use the new to troubleshoot/replace jug/piston in new. I'm a "two is one, one is none" kind of guy. But I had one (broke it), bought one, and now have none! lol. Brainstorming options. Thanks for reply.

JL as I say do not consider pulling the motor apart, you will just open up a can of worms. Cutting the shaft is easy with a grinder and a thin cutoff wheel and all you need for the new shaft is a keyway or a bit of keysteel and make your own key. Half an hour and you should be able to have it all fitted up

Thanks for your input, Norm. I have the tools... Will investigate into what it'll take to pursue what you suggest. When I look into the the differences into the shafts, and my skills with cut-offs and dremels, I don't see a half hour as my estimate! lol I first just have to measure to make sure that I have enough material on the new shaft to mirror the old shaft. Will inform the forum on next step. Thanks again!

One thing I don't know is if you need a bolt in the end of the shaft or does the pump connect to it directly or does it have a pulley. The other thing to be aware of is the Woodruff key is narrower that the keyway in the shaft on the new motor and that will require you to male a stepped keyway. That is easy with the keysteel in the vice and notch it with the grinder

My suggestion with this would mirror what Norm has said.

It looks like they are similar in basic configuration, however that could be deceptive. Just double check that the shaft diameter is identical and that this is maintained if there is any taper. I would use a micrometer but decent calipers or even dividers will do the same job; provided accuracy is consistently maintained.

If they’re not the same diameter in the working/fitting part of the shaft no amount of judicious and careful dremmel work is going to help. They need to be identical or the resulting misalignment will result in catastrophic failure.

According the two IPLs it looks likes someone has already chop part of the new 130902-0016 crankshaft (260922 superseded to 397109). The 492091 crankshaft is the one for 130902-1015. Should be able to swap them as the internal section looks to be the same. The only problem would you need to use the Magnetron coil as the 1015 probably is a points setup.

Thanks AVB... Hate saying, but that its above my technical level. I'm concerned that regardless of whether I modify the shaft or swap it is that I can't back out easily--I'd turn the motor to trash as the parts for these motors seem to be scarce. I'm not following you when you said it looks like someone chopped the new motor shaft? The motor was received new in box. You've got me thinking I should test it! I know better than to assume it works...lol. The shaft doesn't look like what's illustrated in your post--260922 or 397109 as those are keyed protrusion. The shaft on new motor I have is notched.

Something I question is the couplings between the shaft and the pump... I've attached pictures of what mated with the 130902-1015. The pump side looks like it may fit a standard coupling. If this is the case, why couldn't I buy a coupling that mates correctly with the new shaft? I'd also be open to decreasing the length of new shaft if necessary. At this point, I question if purchasing a pump that mates the new shaft is something to consider?

Thoughts?

Looks a pretty straight forward fit to me

Hi JL43062 Norm and AVB,

Something like this ,I would normally just change the crank if the main shaft is the same diameter in the bearings.

I've had a few and when I change the crank the stroke is different or the big end is a different size and I just pull the gudgeon
pin out from the crankcase end and swap the conrod with the crank , no need to take the piston out or remove the head.


I've seen cranks cut down but I just prefer to change the crank, I normally change the crank in motors with bent cranks
and put a shorter crank in.

Cheers
Max.

Call me old fashioned but I would not pull down a brand new motor to fit a second hand crank in it

Max, If my Briggs info is correct then the throw is the same. Now with Norm on the not using the old crankshaft; unless, necessary.

I have done horizontal shaft log splitter engines new engine installs where I had to remove up to 3/4 of an inch of the crankshaft PTO end so I could reuse the pump mounting brackets.

One question the comes to mind here. Is the pump using the 7/8 step down or is using the full one inch shaft? If using the full one inch then it is simple to shorten the crankshaft. Otherwise there are two options.

1>Extend the current pump mounting bracket if no clearance issues.

2>Install a different pump.

I’m gathering that JL43062 hasn’t had much experience stripping and rebuilding engines and that the crank swap operation is outside his comfort zone. That’s why I was trying to minimise the challenging steps.

If you’re new to rebuilding then watching a few videos of others doing the same procedures can improve confidence. You can also grab a junk motor from recycling, strip it and reassemble it for practice. The second one is so much easier than the first and so on.

Swapping bits around isn’t a problem provided that they’re the same in the critical dimensions. As an example: I’ve rebuilt a few car engines using mix and match for cranks, blocks, corods, pistons, heads etc. As long as clearances and other dimensions are within tolerances then it works just fine.

You're right, Ironbark--I have little experience stripping/rebuilding engines. The extent of my knowledge is rebuilding chainsaw, but parts were available and videos were a'plenty. Also, I have several saws so the risk was less if I failed. I only have this one splitter that is currently out of commission. Splitting season is around the corner so aim to have it ready.

I'm really trying to keep up/follow everyone's considerations/suggestions. They've been good... Very helpfuI, and food for much thought.

I still don't understand how I could modify the 3" shaft (attached '0068') to spec of 2" shaft ('0066'). The length isn't what concerns me--a cutoff wheel handles length easily. But the keying of the shafts is entirely different. If was to cut the 3" shaft to 2" in my first step, what is my next step? To me, it would seem I'd need to "turn" (in a lathe) the shaft to maintain uniform diameter? I can't imagine trying to do this with the shaft "static" while I'm operating dremel. I really feel like I'm missing something here. And then, if somehow successful at removing the material to the spec displayed in '0064', I'd still need to figure out the protruding key.

Doesn't sound like an option, but from my layman mind, I'd like to purchase a pump coupler that mates with the '0068' shaft. Would likely have to reduce the length of the shaft, but this is fine (this part I'm comfortable with). But moot as I guess such a coupler doesn't exist.

If nothing else, I just hold to the new motor for rainy day... Work on the old motor that seized up due to low oil running on very un-level surface. I've read these have forgiving tolerances that bode well at a chance that once unseized it still has compression... But time will tell as I work on it. And working on something that is broken is always justified. My hope was to have two identical motors, but the shaft is a critical component and it greatly differs between them. It happens...

Aside...
Unseizing piston... I removed the plug months ago and flooded the cylinder with penetrant. Attempting to pull start still is unsuccessful (I expect this) at getting it unseized. Is next step attempting to torque the shaft, or better to access the piston in attempt to break it loose (thinking piece of dow and mallet). If torguing shaft, I've been thinking of what kind of "lawnmower blade" type part I have that I could attach to the shaft to gain leverage. The plan isn't really to crank the hell out of it, but to jar it back/forth some in hopes that something gives. Ideas on this?

Thanks to everyone. Big help. I'm learning a little too.

Okay you going to need to the engine side Lovejoy coupler (Sintered Iron Jaw Coupling Hub) to one that has a 1" bore instead the current 7/8" one. What the OD diameter of the Lovejoy coupler (Sintered Iron Jaw Coupling Hub).

Alright. If there's an option to change the coupler then this looks to be least intrusive. Not a perfect "two is one, one is none" as coupler will need changed specific to motor... but pert near. There are many options for that coupler. I don't understand difference between "Sintered" and "Lovejoy"? Sintered has two teeth?; Lovejoy, three? (teeth are mating protrusions with spider; spider mates both) I apologize that my terms aren't likely correct--just trying to communicate best I can.

If Lovejoy is what is in use now (three teeth), sounds like pump side would need replaced also if using sintered?

When I sort grainger 'jaw coupling hubs' by 1" bore diameter I only see a key of 1/4" by 1/8". All of these seem to be "male" shafts, where the key protrudes. The shaft I have would be female key, right? I'm not seeing a coupler of this type. Possibly overlooking it.

If this is an option, I'd like to pursue it.




I really appreciate everyone's help with working through this problem. Truly the real value of internet... I owe The Australian gear heads (meant to be a compliment) a Fosters--or whatever the beer down under is?; Only brew I've had in TN was at Morristown--1907 brewery. Nice place. On me!

Thanks.

Ok so from what I see the old shaft is 7/8th and the new is 1 inch. Just find somebody with a lathe in their shed and get them to bore the coupling. Try your local bearing shop and they usually know somebody who can do it. He will also be able to set you right on the keyway which is a simple fix. And as I don't know if the coupling is held on by a bolt in the end of the crank ( I doubt it) while you are getting the coupling bored out I would get a grub screw fitted in the coupling so it locks down on the keyway another simple job if you have the tools

Boring and broaching in a keyway is something only a machine shop can do normally. Also going to 1" is going to weaken the coupler quite a bit.

Okay you got the L075 style couplers. The ones you need are the L095 ones. But you need make sure you have the side clearance for 2.1" Diameter plus some wiggle room.

The 7/8" one uses a 3/16 " key and the 1" uses a 1/4" key. Prices are for reference only and are USA prices.

Hi AVB,
Boring it out is not going to weaken it, you are only taking 1/16th of an inch out of the wall thickness and you don't need to broach the keyway out, a grinder will quickly take 1/16th of an inch off a bit of keysteel