re-engine an Eska lower unit. anyone use lovejoy, jaw type couplers?? or what??

[gary79]

I have an old 4.5 horse Eska lower unit. I am looking at a new B&S engine, 4hp, shaft is 7/8" x 1 13/16", a log splitter or pressure washer replacement motor is what it is tagged as, heavy flywheel, no brake. I plan on making an adapter or mounting plate out of aluminum plate to match the engine to the lower unit.

the problem is coupling motor shaft to the existng lower unit shaft

the lower unit drive shaft is splined, appears to be 7/16" in diameter. I also have the original coupler, splined on one end, and the other end has a keyway, 5/8' hole. the origninal coupler is 1 1/8" in diameter. my original thought was to bore the coupler out to 7/8" but that means that collar is only going to be 1/8" in thickness, and there would be no keyway. there's not wnuf metal left after boring out for a new keyway.

looking at Lovejoy jaw couplers, anyone use them???

open for any and all suggestions, solutions.
I want to get this project going. gonna be crappie season soon!!!

 

[mrcrabs]

Re: re-engine an Eska lower unit. anyone use lovejoy, jaw type couplers?? or what??

check out the Eska Electric post below.
The coupler in the article seems like a good Idea. I can see many adaptations to his solution when it comes to shaft size. You take a 3/4 impact type socket have the ratchet end machined to fit the engine shaft then weld a appropriate sized nut to the drive shaft and your there.

The eska coupler you have is more than likely the notorious eska clutch and might give you some trouble working the way you want it to.

http://forums.iboats.com/showthread.php?t=460641

 

[gary79]

Re: re-engine an Eska lower unit. anyone use lovejoy, jaw type couplers?? or what??

I saw that electric conversion and their "socket" solution. I hope I can explain adequately how I may have some problems with that method. the motor shaft is 7/8" diameter, that means the socket will need to be bored out to 7/8" diameter, that will require a sizeable socket in outside diameter, and allowance for a keyway slot needs to be added into the equation. so imagine a top view of the socket, start with 1/4" of metal collar, add 7/8" bore hole, add another 1/4" of metal collar = a socket of 1 3/8" in outside diameter, keep in mind that the 1/4" metal collar surounding the shaft will need a keyway slot cut in it, eating into that 1/4" metal collar. that doesn't leave much metal around that keyway slot. so I wiil have togo to an 1 1/2" outside diameter socket, chances are the nut that fits in that socket will be sizeable and that nut's hole will exceed the driveshaft diameter of 7/16". follow me???? perhaps reviewing the original coupler dimensions will put in into perspective.

review the stock coupler dimensions. the outside diameter is 1 1/8". the stock coupler collar has a splined 7/16" bore on one end,. the other end has a 5/8" bore, the surrounding metal collar is
1/4" thick with a 3/32 keyway cut into it. so if we view the collar from the top and add things up..... 1/4" metal collar + 5/8" bore + 1/4" metal collar = 1 1/8" outside diameter.

an impact socket will be needed because they are stronger than a conventional socket. I have concluded I need a socket with an outside diameter of 1 1/2", minimum of 1 3/8". and it all depends on the size of the nut that fits in that socket and what bore the thread hole is in that nut. otherwise, I'll have to sleeve the bore on the nut down to 7/16".

I took my ideas to a machine shop and they suggested 2 things, the lovejoy jaw couplers, or disassembly of the new engine, so the crankshaft end can be turned down to a 5/8" diameter and use the original coupling collar. I'm not too hip on disassembling a brand new engine. and the lovejoy couplers I have looked at online do not have a keyway when they get to the 7/8" size. I'm also trying to keep my machine shop bill to a minimum. the shop I deal with is very capable. they have worked on my stuff/projects for about 20 yrs. the shop foreman recommended the lovejoy coupler, and the local merchant that is the dealer. he also said, I could just give them all the pieces/parts/motor/lower unit and they would figure it all out, and hand it it back to me as a working unit. probably at an addl cost of $150-$200. the cost of the motor is $150, so if I let them do the all the work(coupler, adapter plate) I'm looking at $300 to $350.

 

[mrcrabs]

Re: re-engine an Eska lower unit. anyone use lovejoy, jaw type couplers?? or what??

What ever you decide to do Gary I hope you will share it with the forum and post some pictures.

 

[gary79]

Re: re-engine an Eska lower unit. anyone use lovejoy, jaw type couplers?? or what??

went to the local Motion Industries, Inc store, and ordered a Lovejoy joy coupler, approx $20. it'll be here this Monday. 7/8" diam one jaw half and 7/16" on the other jaw half

 

[gary79]

Re: re-engine an Eska lower unit. anyone use lovejoy, jaw type couplers?? or what??

looks like this

 

[mrcrabs]

Re: re-engine an Eska lower unit. anyone use lovejoy, jaw type couplers?? or what??

Not wanting to knock that coupler but I have considerd it from time to time but lateral motion seems would be excesive according to the design. I guess you could fill up the lower unit with lubraplate and keep the oil check religiously in the engine because i can see the oil seals getting beat out quickly....or I could be wrong:facepalm:

 

[gary79]

Re: re-engine an Eska lower unit. anyone use lovejoy, jaw type couplers?? or what??

I'll see what happens. the local supplier got the wrong size coupler in today. so tomorrow the correct should be in. the coupler is designed for a little "slop". the machine shop foreman and the counter guy at supply house said that this would work. using a log splitter motor with heavy flywheel, so it should be more balanced that say a lawn mower engine minus the blade. actually lawm mower engines count on the blade to help balance. the coupler that goes on the engine should be okay. the 7/16th coupler going over the splined shaft is the "worry" part. if it doesn't work them and oil seals go out, then will pull the crank out, and have machine shop cut it down to 5/8" so I can use the original coupler.

I pulled the shaft assembly out of the lower unit, so the I can cut/grind a keyway into it. while I was doing this I was checking if I could have used a socket/nut as a coupler. I concluded the nut would have to be welded once the shaft was asssembled in place, cuz if the nut is welded to the shaft before assembly, it will not fit thru the lower unit casting.

 

[mrcrabs]

Re: re-engine an Eska lower unit. anyone use lovejoy, jaw type couplers?? or what??

it will not fit thru the lower unit casting.

well that sucks,

the splined end of the shaft is 7/16 right? shouldn't the lovejoy coupler have a set screw that would hopefully hit between the splines??

 

[gary79]

Re: re-engine an Eska lower unit. anyone use lovejoy, jaw type couplers?? or what??

the shaft is 7/16" but the set screw will not fit between the splines, besides you don't want to rely on just that set screw to transmit the power. I had to file a keyway to fit, and I slightly widened the area between two splines, and used a dremel tool with a cutter blade to add some depth. the orignal spline coupler still fits. I've kept that option open in case this doesn't work, I could take the crank out of the motor and have the crankshaft turned down to 5/8".

anyway, got lots of work done. check the pics. I need to make some mounting blocks between motor and alum plate. I have some 1" and 2 1/2" black nylon "dowels" that I got from work a long time ago(i'm retired telco splicer). need to cut them to a height of slightly less than an inch, drill hole thru the middle for the mounting bolts to pass thru. tighten everything down, add oil and fuel and test run it. tomorrow could be the day. I think I'm gonna call it the Briggska. I used 2 drills, 2 sizes of hole saws, a dremel tool+ attachments, hand files, and a cut off tool and luck. never forget the luck. I used 3/8" alum plate, 12" x 18", cost $80. ouch! steel was $40 but 23 lbs, the alum was 8 lbs, less now with the holes in it. I've got a little Flip brand video cam, so if it works I'll post up a video.

 

[mrcrabs]

Re: re-engine an Eska lower unit. anyone use lovejoy, jaw type couplers?? or what??

Briggska

I like it, when you get done we will add this to the Eska Files

 

[gary79]

Re: re-engine an Eska lower unit. anyone use lovejoy, jaw type couplers?? or what??

if this one works okay, I might build another. the guy across the street has an old Eska. it's missing parts and he thinks it's worth $35 still. he's a little wonky. I think I'll offer him $10. I also have an old Mercury 10hp lower unit from a 1947. it weighs a ton tho. but first things first, finish this one.

 

[gary79]

Re: re-engine an Eska lower unit. anyone use lovejoy, jaw type couplers?? or what??

it's complete, except for the "tiller" handle. so I hauled it out of my shop, added the liquids, and it runs!!! yay! not gonna be terribly fast. not sure what rpm it turns, but I think the old 2 cycle spun a little faster. it's fairly quiet. I think I can live with that. if it was too noisy, I was gonnna have my buddy, Ray, who has an exhaust shop, fab a down & away pipe. he'd probably do it for $5 just for Ss &Gs. will get some pics up. can I put a video on here direct from my PC?

 

[mrcrabs]

Re: re-engine an Eska lower unit. anyone use lovejoy, jaw type couplers?? or what??

you need to use something like youtube to post a video

 

[gary79]

Re: re-engine an Eska lower unit. anyone use lovejoy, jaw type couplers?? or what??

see if this works. first time I have uploaded to youtube.

the fuel in the tank is half old(w/stabil) and half new. it ran better once the new was added.

lind doesn't work, go to you tube and search for "briggska"

 

[mrcrabs]

Re: re-engine an Eska lower unit. anyone use lovejoy, jaw type couplers?? or what??

Check out this Gary,

http://cgi.ebay.com/ebaymotors/ws/e...akeTrack=true&ssPageName=VIP:watchlink:top:en

no affiliation with seller

 

[gary79]

Re: re-engine an Eska lower unit. anyone use lovejoy, jaw type couplers?? or what??

hey, that ebay unit looks really good, a neat clean conversion. I wonder where he's getting new Tecumseh engines. as they are no longer made. he cut his adapter plate much smaller than mine. I made mine large because the original Eska "handle" part was broken on mine.

 

[mrcrabs]

Re: re-engine an Eska lower unit. anyone use lovejoy, jaw type couplers?? or what??

One thing is RPM, that lawn mower engine is just not going to achieve the RPM needed to crank the prop to the design spec's. re-proping may be an answer but I wouldn't put money in it no mater how pretty it looked IMHO my old 3 hp tanaka could eat that guys remaned 4hp Eska and you can buy them all day for $250 or less.

Gary you can buy brand new tecumseh engines all day long cheap from http://www.smallenginewarehouse.com/ you can even find the original AV600 AV750 and AV817 short blocks and many others even older....just got to look