Thanks. I estimate there is clearance in the pump housing... I'll measure when I get a chance to be sure. Looks like that L095 '1 in' would to the trick. I plan to purchase, then evaluate once received. Will then decide whether I hire a machinist or not. Thanks!
Taking a 1/16 out of the key can be a problem if the hub (drive) has a hundred thou depth to the keyway as you would remove around 62 thou leaving a 38 though depth, that's less than 1 mm of key engagement.
Sometimes I have hubs that you can't remove 1/16 as they are not very thick to start with and some casting shifts leaves the machining thin on one side.
I wouldn't have a problem putting a second hand crank in a new briggs motor as it should measure up fine and is not much different than a reco motor.
As Ironbark suggested there are lots of youtube videos dismantling and assembling Briggs motors.
Probably the easiest thing for you to do is to change the coupling and shorten the shaft as others have suggested .
I would also try to free up the original motor ,I've had a lot of Briggs seize on the big end con rod from running out of oil , put some WD40 in the crank case or a fair amount of oil and make sure the lubricating fluid reaches the rod by tipping the motor over then use a big shifter on the crank to turn the motor , you will need a key in the crank so the shifter doesn't slip and this can sometimes damage the key if it's really tight to free up ,but you can use an old key or buy a new key.
Once the motor is turning remove the spark plug and make sure the motor turns easily this can take a while , sometimes I use a drill to spin the motor over.
I've had a lot of Briggs motors that I've done this too and they have lasted many years afterwards ,I've also know sometimes they don't last very long if the conrod lets go and some that people remove the conrod and linish the alloy off the crank big end, those linished seem to have too much clearance and you end up with knocking noises and don't last as long.
We’ve got some solid information now. As the two shafts are of different diameters you can’t simply swap them between crankcases as the major diameter is greater on the new shaft than the the original.
The couplings, as described by AVB, may be the simplest solution. Doing this you can rebuild your old engine and have a “spare”. If you don’t want to rebuild or can’t find the correct coupling then any decent machinist will be able to turn down your current coupling. However, before ordering one I would just check that you have clearance with the new shaft length. If it’s a through shaft with an opening at the back ignore what follows
You may be able to measure the depth available with the depth gauge on your calipers. Measure the shaft length from the mating surface with the pump and compare that with the corresponding depth available on the pump side from the same mating surface. Normally, you’d want 10thou or about 3mm of clearance as a minimum.
Sometimes getting an accurate measurement is very difficult in which case you can manually check by mating the engine up. To do this you’ll need to remove the 7/8 coupling and place a small spherical ball of machinists putty on the end of the shaft. You can substitute blue tac or kids play-dough. Just make sure the end of the shaft is completely clean and free from grease or oil.
Carefully, making sure not to catch the end of the shaft on anything, align and bring the two components together and then, equally carefully, pull them apart. Inspect your ball of putty and if it is compressed measure the extent of any compression.
Also, before pursuing machining of your existing coupling, I’d double-check for taper on both the new shaft and your existing coupling. If the coupling is tapered, that is used to reference the location it is designed to sit at and control for clearance. If the new shaft is tapered then you’d need to do some maths to make sure you’re getting the correct fitment. Machining a taper requires a little more work than a straight bore.
We’ve got some solid information now. As the two shafts are of different diameters you can’t simply swap them between crankcases as the major diameter is greater on the new shaft than the the original..
From what I see both new and old shafts are 1 inch but the old shaft is stepped down to 7/8 so cranks are interchangeable.
Boring out couplings we did on a regular basis when I was building fire fighting pumps ( some with very big turbo Cummins motors) and we never ever had any issues with the couplings failing, but anyway what would I know I'm done with this topic
I give to experience but I just don't have the time nor want risk a modified repair on a customer's machine.
And Max is right the older worn crankshaft will in the new engine but why be so penny pinching on a good piece of equipment. It does cost that much to install the correct parts; unless, it is that hard to get them. Yes I understand things are over expensive in your neck of the woods but they getting just as expensive here too. Shipping fees has nearly double in the last year along parts costs.
But course I have seen some of the makeshift that Aussies do like this one.
A lot of the websites time out if you take a certain amount of time to do your reply so when you hit post reply all is lost, I open a new text document and copy and paste the reply before hitting send ,that way if the site looses the reply I can just copy and paste my reply again and hit post reply. I only do this if it's something you don't want to type out again .
Machining is fine if you can find someone like Norm to do decent machining at a fair price.
I've had no luck with fitters and turners in my area ,if I take a simple job to them they are not interested and I have to contact them multiply times to ask if the job is finished ,ends up taking a month to remove 1 mm of steel then they over charge and stuff the job up.
The last job I had was to turn down square axle spindles to fit in a trailer drop axle ,the square axle had to go in a round hole, I was converting a disc brake trailer axle that needed new discs and calipers to electric drum brakes because I had the parts.
I explained what I wanted done and gave them the square spindles with a bit of thin alloy sheet to clamp in the lathe to use as a soft jaw so the seal surface was not damaged .
Get the spindles back weeks later and I have jaw mark damage on both where the seal runs from the lathe chuck ,I had to spend time linishing the marks out and now they will be slightly undersized.
I guess every time I get a job done they have no common sense , don't care or they are getting the first year apprentice to do the work and charge top dollar.
Update. Was able to get seized motor unseized and started. Did this using the coupler (without spider) and small pry bar. I was thankful to have it turn without applying much force. The motor has always been relatively difficult to start, and was consistent in this regard. Once started, it missed some at low rpm (I never run it low when in production), but ran well when throttled. Happy about this--haven't tested under load yet though. Compression is 75 and the new motor tests roughly the same. This is a big positive to me, but testing old motor under load, over time, will be the real test.
I'm undecided on what I'm going to do with the new motor. Purchasing a coupler that mates with the shaft would be good insurance for future splitter use case. But I'm unsure of what use cases I'm sacrificing by cutting down length of shaft? So I'm hesitant to do this until forced if splitter need arises. This is where I'm at.
Thanks to everyone that spent time helping research, determine/weigh options, and provide guidance. I learned from you all. Truly appreciated.
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