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Flywheel removalTHE NUCLEAR OPTION

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barato

Contributing Member
"hi all--

trying to get fly

"hi all--

trying to get flywheel off an old 40hp Johnson twin.
it was stored outside by prev owner, upside down.....so all the water that got into housing during years of our summer monsoons pooled inside cutout area around magnetos, which would normally be under flywheel.
lots of crusted dried mineral deposits on mag assy and results so far indicate that the flywheel is stuck to the crankshaft taper waaay better than usual.
i've tried every trick i've learned in 30ish years of working on saltwater engines....gallon size Wd40, PB B'laster, heating flywheel with torch, whacking from below with hand sledge while prying, whacking side of flywheel with brass hammer, etc...no luck. one of the 3 puller bolt holes in the flywheel stripped out so i'm now using giant 3-jaw puller and planning on writing off the flywheel.
anyone have any ideas? i'm about ready to get out the cutting wheel and slice the flywheel until i can split it with a cold chisel. THAT will no doubt be a party... hope the crank nose isn't either too bunged up or rust pitted.

thanks!"
 
"is this really worth the time

"is this really worth the time,what do you think you will find when the rest of this engine is opened up"
 
"this is my thoughts also,....

"this is my thoughts also,....i think,i would right this one off as 'too far gone',and get another."
 
"actually, it seems to have go

"actually, it seems to have good compression and otherwise not be too worn in all the moving assemblies, once i got the years of crud cleaned off. but yeah, if crank nose is pitted, it may be history.
i do have spare '64 which could be parts engine and am curently watching a flywheel/mag assy and a complete powerhead on fleecebay, but i'd like to try to get this one going.....sort of personal challenge to show my wife how cheap i can get this boat going.
smile.gif
"
 
Chuck it in a tank of diesel f

Chuck it in a tank of diesel for 3 months...its an old vintage bike restorers trick.
 
"You need to put a good puller

"You need to put a good puller on it (retap the holes if necessary) torque it up real good, start the nut to protect the threads then whack the crank with the BFH. This should pop it."
 
"lets re-cap--- a bit-----this

"lets re-cap--- a bit-----this eng,...has had wtr intrusion.....cant get flywheel off...and its an older model..............
in my opinion,...depending on the wtr intrusion,.......scrap it........"
 
"You have time on your side an

"You have time on your side and a point to prove. I would try Andys' idea with the Diesel. Is this a spare motor? If it sat in a bath till summer, that six months, what have you not achieved? Make sure it is not resting on bottom of drum. Water heavier than diesel. It took years for it to be in its present condition. Patients required. You should be able to salvage something. Who knows, if ok with [W] you may try to locate another 40 HP. No great cost to buy or store. Make sure you know the model number before the bathing. Keep us posted."
 
"thanks Jon & everybody el

"thanks Jon & everybody else. yeah, i realize it may be parts motor, but Jon hit it on the nose...i'd love to show my wife that i can get this boat going for cheap. the diesel idea gives me an idea tho....i have the gallon of WD40...why not flip motor upside down in shop, fill the same cavity that was filled with water with WD40, wait, and repeat"
 
"WD40, OR. Mix Kero and diesel

"WD40, OR. Mix Kero and diesel and follow your process as if it was the WD40. Initially the thinner the better. I do not know if auto trans oil will cut non ferros oxides???? [ anyone have thoughts!!! ]. Patients required. Have a collection pan under the motor and the motor supported= max filling of cavity. LET SIT. Ricks' idea of nut on the thread { flush } and tap is good. Vibration will do good. Then invert again. The quicker the entry rate into the pan the better the signal. Your are the judge. You can be the quiet achiever. No award given for a record removal."
 
"I have seen " Kroil "

"I have seen " Kroil " do miracles. Especially on tapered propeller shafts.
Like Rick,, Soak with Kroil, put on a good puller and apply plenty of tork and then let sit. Re-apply Kroil every few hours as you let it sit. Time is the key. I've seen 24 to 48 hours maybe more in this case. It's been said "what have you got to lose?" Good Luck ! Let us know how it turns out."
 
"Proper bolts in puller/flywhe

"Proper bolts in puller/flywheel threaded holes, screwed in at least 3/8". Center spindle tightened down to an extreme tightness. Large screwdriver or tool of your choice prying up on flyheel.

Smack center spindle straight down with the biggest hammer you can find, as hard as possible."
 
"Bruce,

An impact tool capa

"Bruce,

An impact tool capable of 350 foot/pounds usually gets the job done if the threads in the flywheel holes hold up.

Or you could suspend the flywheel and engine with a couple of steel plates under the flywheel. Leave the flywheel nut on loosely. Take a bronze shaft and a sledge hammer and pound the crank out.

Tony"
 
"it's soaking in the pan a

"it's soaking in the pan as we speak. thanks for all ideas....Joe and TOny, unfortunately i've already destroyed one of the puller holes so i'm using my huge 3-jaw puller and planning on writing off the flywheel.
i'll probably try another heat-n-beat session this weekend. Tony, are you suggesting using the impact wrench on the puller center nut?
one other suggestion from a friend here was to get puller & prybar in place & tensioned, then go at bottom of flywheel with flat head on air impact chisel...he thinks the "sharpness" and velocity of the blows from the air chisel works better than hitting with big hammer.
i'm gonna try everything until we get it off, so i appreciate all the different approaches. the acetone & ATF idea sounds interesting but not sure how to cover pan well enough to keep shop from being full of evap'd acetone!"
 
"Gerard J., Acetone {hydro car

"Gerard J., Acetone {hydro carbon} would that disolve non ferros oxides?. Is there a specific mix rate for auto trans fluid and acetone. Jon"
 
"Sorry it took me a while to t

"Sorry it took me a while to track this down for you but I found it, it was a controlled test by machinist magazine. 8 hr soak before testing.

http://bbs.homeshopmachinist.net/showthread.php?t=27429&highlight=penetrating+fl uid+test

ATF mixed 50/50 with acetone, it beats the crap out of anything else out there.Power steering fluid with acetone works too. The idea is have some sort of fluid to prevent the acetone from vaporizing immediately.

Severely rusted parts can be dressed with muriatic acid and liquid soap, soap being a surfactant."
 
"I'm a fan of the impact d

"I'm a fan of the impact drivers too, I did the balljoints on my 1 ton truck with one, using a balljoint press , the impact tool makes them slide in like they are a slip fit.

I would definately try retapping the flywheel for bigger grade 8 bolts and putting an elec impacter to the center bolt."
 
"Gerard J. That is a good site

"Gerard J. That is a good site!. For an inboard motor and hence, this is unrelated. Presently soaking a cast OSCO 90 degree and riser in canoal oil and will sit there untill required. The logic is- oil will transfer into the porous cast. Before required, will allow to drain and then install. During normal operational running the oil will be glazed into the risers and elbow and will help retard rust. Any thoughts. I will do a seperate post on the inboard site. But thought of some feed back here. Jon"
 
"New user here,first post,I&#3

"New user here,first post,I've read on the smokstak.com website that the old timers used to use pure beeswax,heat the part smear beeswax on and it'll penetrate better than any solvent.Haven't tried it yet but thay say it work's!"
 
"Gerard, thank you so much for

"Gerard, thank you so much for posting that stuff! and your idea of drilling flywheel out and retapping for 5/16 bolts is bluddy brilliant....duno why i didn't think of that....wonder why factory didn't use 5/16 in the 1st place? heading off to sunny Mexico for fishing this week and will leave it soaking in the ATF. you think xylene or lacquer thinner would work for the acetone, being as how i have gallon of each?

THANK YOU!!!"
 
"i'd wondered what i was g

"i'd wondered what i was going to do with the ATF left over from ex-girlfriend's volvo, since i never plan to have another auto trans vehicle..."
 
"Believe it or not we have use

"Believe it or not we have used real peppermint oil, not close facsimile, on metals joined by electrolysis to great results. Patience is always the winning ingredient though."
 
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