Old K&B 7.5...20+yrs sitting...crank frzn, HOW to unfreeze...some pics

[frankdoman]

Pictures are now attached >> OK, took the motor apart and was pleasantly surprised to find grease and oil in most spots...like drive shaft/lower unit, piston/cylinder. However, I can not get the crank to turn. I have it just in the crank housing, with carb off. Soaked in gas overnite, now have it doused in Liquid Wrench. I believe it should turn pretty freely by putting in the threaded shaft for the starter cone/flywheel and turning it there, or by turning it from the bottom with the pin that goes into the back of the piston...correct? Should I be able to knock the entire crank shaft assy out of the housing and thru the bearing at the top, how ? Can I try vice grips or something to turn the crank and if so grab it by the threaded shaft on top (where the cone attaches) , or by the pin on the bottom that goes into the back of the piston ?Neither place can I budge it at all...does look a little rusty/dirty espec when I look close up at the pictures of the inside...see pics. Any ideas on how to free this crank up, assuming it should spin/turn pretty freely ? I have the old model, per the spec sheet, with the set screws that held the carb in the carb body throat (now all removed). Piston moves in the cylinder nicely and some lube in there, and drive shaft well lubed and looks in good shape. Ideas on the crank welcomed...My crank does NOT look exactly like the one in the spec sheet (surely mine is older), and on the bottom has another spacer or bearing and the pin that grabs the piston looks like it is pressed in vs. the spec sheet model, but pretty similar...can I attach the treaded shaft, the cone, and the locking nut on top and then try to turn the crank by grabbing the cone with channel locks, or by putting bits into the holes and twisting, or something if the housing is in a vice ??? just wondering...I miss the squirrel talk....thanks. F

 

[kesso2118]

Frank,

There will be better people than me who will chime in here and give you advice but until they do, here are a couple of points to consider:

1. Don't use vice grips or anything brutal on the crank pin, crankshaft or crankcase
   
2. Yes, the crank should spin freely in the housing, however, if yours doesn't it's because it is "gummed up" or rusted and stuck to the front bearing
   
3. As per some of the earlier advice, have you tried heating the housing to help remove the crank? You may have to do it a few time but it always works...eventually.
   
4. Don't try and push the crank out through the front bearing (i.e. Flywheel end), it needs to go out the other way. I would try removing it by reassembling the front housing with the crankcase, using heat and placing the crankcase on a solid piece of timber with a hole in it large enough to allow the back of the crank to move through it. You place the crankcase assembly on the timber with the back of the crankcase sitting over the hole and the flywheel end pointing up. Once the front housing has been heated you should be able to give the threaded end of the crank a sharp (but gentle) tap and the crank should drop out the back of the crankcase and into the hole in the timber block. To prevent burring the thread it might be best to screw in the flywheel bolt and give it the sharp tap.
   

I hope this helps.

Good luck,

James

 

[frankdoman]

Frank,
There will be better people than me who will chime in here and give you advice but until they do, here are a couple of points to consider:

1. Don't use vice grips or anything brutal on the crank pin, crankshaft or crankcase
   
2. Yes, the crank should spin freely in the housing, however, if yours doesn't it's because it is "gummed up" or rusted and stuck to the front bearing
   
3. As per some of the earlier advice, have you tried heating the housing to help remove the crank? You may have to do it a few time but it always works...eventually.
   
4. Don't try and push the crank out through the front bearing (i.e. Flywheel end), it needs to go out the other way. I would try removing it by reassembling the front housing with the crankcase, using heat and placing the crankcase on a solid piece of timber with a hole in it large enough to allow the back of the crank to move through it. You place the crankcase assembly on the timber with the back of the crankcase sitting over the hole and the flywheel end pointing up. Once the front housing has been heated you should be able to give the threaded end of the crank a sharp (but gentle) tap and the crank should drop out the back of the crankcase and into the hole in the timber block. To prevent burring the thread it might be best to screw in the flywheel bolt and give it the sharp tap.
   

I hope this helps.

Good luck,

James

thanks James...I will try the heat and gentle tap method on the threaded rod or the rod with the cone attached and try to get the crankshaft to come out the back/bottom...will let ya know.

Frank

 

[John Kubitz]

The best way to free up the crank is to put it in hot (about 150-180) stright antifreeze. I had a frozen crank in an old airplane engine that I used kroil for 3 weeks no luck but the antifreeze did the trick.

 

[frankdoman]

The best way to free up the crank is to put it in hot (about 150-180) stright antifreeze. I had a frozen crank in an old airplane engine that I used kroil for 3 weeks no luck but the antifreeze did the trick.

Dang, I never heard of hot anti freeze to ungum something...good idea John. Will use this as we go forward. Thanks.

Frank

 

[topfuel443]

While probably not 'EPA' (or wife) approved, Antifreeze in a crockpot overnight is MAGICAL. It does amazing things for old gummed up/corroded aluminum.

 

[frankdoman]

wow...learn something every day. Will have to get my own crockpot at a garage sale.

F

 

[Dan Hydro]

Frank,

you were given the same trick I told you about on RCU,

now you know the crockpot really works.

Dan.

 

[frankdoman]

I am sure the crock pot will work....shocked I never heard about this little cleaning trick until I retired ! Thanks Dan.