How do you fix broken fins on cylinder?
- Nelson
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How do you fix broken fins on cylinder?
21 Mar 2011 02:06
No I didn't break any...
I sometimes see good used deals on performance piston kits with a matching cylinder, but it has a broken fin so noone buys it or it sells cheap. I might buy one of these if the repair is simple/cheap enough to do. The engine has to look right, I don't want busted stuff on it!
I don't weld aluminum, but I'm guessing a pro could easily weld on a piece of plate and then shape it to match. Actually I could do a nice job of the shaping myself, but I can't do the welding.
Does this sound like something that would be easy for a pro welder to do? Is there anything I'm overlooking?

I sometimes see good used deals on performance piston kits with a matching cylinder, but it has a broken fin so noone buys it or it sells cheap. I might buy one of these if the repair is simple/cheap enough to do. The engine has to look right, I don't want busted stuff on it!
I don't weld aluminum, but I'm guessing a pro could easily weld on a piece of plate and then shape it to match. Actually I could do a nice job of the shaping myself, but I can't do the welding.
Does this sound like something that would be easy for a pro welder to do? Is there anything I'm overlooking?
Restoring and customizing a KZ1000. Click here to read about it.
Plated KTM, DR650, KZ1000, Former MC mechanic (eons ago). 40 yrs. of dirt and street.
Plated KTM, DR650, KZ1000, Former MC mechanic (eons ago). 40 yrs. of dirt and street.
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- wireman
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Re: How do you fix broken fins on cylinder?
21 Mar 2011 02:47
pretty much sums it up!
some guys buy junk cylinder heads just to use them for pieces to fix fins on good cylinder heads.
some guys buy junk cylinder heads just to use them for pieces to fix fins on good cylinder heads.

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- tinlizzie37
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Re: How do you fix broken fins on cylinder?
21 Mar 2011 11:38
Hi Nelson, I know it can be done. I repaired the cylinder fins on a H2 Kaw engine the was in a wreck .Not only the fins, but all the motor mount castings were broken off, and it had a large hole in the transmission. All turned out great. Bob
Bob KZ 650 E1, En 450
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- stonemaster
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Re: How do you fix broken fins on cylinder?
21 Mar 2011 11:45 - 21 Mar 2011 11:46Nelson wrote: No I didn't break any...
I sometimes see good used deals on performance piston kits with a matching cylinder, but it has a broken fin so noone buys it or it sells cheap. I might buy one of these if the repair is simple/cheap enough to do. The engine has to look right, I don't want busted stuff on it!
I don't weld aluminum, but I'm guessing a pro could easily weld on a piece of plate and then shape it to match. Actually I could do a nice job of the shaping myself, but I can't do the welding.
Does this sound like something that would be easy for a pro welder to do? Is there anything I'm overlooking?
thats how one of mine was repaired on another bike, dude shaped a piece of aluminum and tig welded it
Last edit: 21 Mar 2011 11:46 by stonemaster.
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- kawman14733
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Re: How do you fix broken fins on cylinder?
21 Mar 2011 14:36
if you can braze with a torch , build it up with aluminum rod and grind it /file to shape...
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- 531blackbanshee
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Re: How do you fix broken fins on cylinder?
21 Mar 2011 16:11
if it is going to be painted i have seen them tape cardboard under the fin and pile jb weld on let it dry and shape it.
we have a 1953 indian chief 80" engine that had broken fins on the aluminum flat head.the welder sat down and ran little beads down each fin until they were built up enough.then metal finished them back and you can not tell they were ever broken.
leon
we have a 1953 indian chief 80" engine that had broken fins on the aluminum flat head.the welder sat down and ran little beads down each fin until they were built up enough.then metal finished them back and you can not tell they were ever broken.
leon
skiatook,oklahoma 1980 z1r,1978 kz 1000 z1r x 3,
1976 kz 900 x 3
i make what i can,and save the rest!
billybiltit.blogspot.com/
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1976 kz 900 x 3
i make what i can,and save the rest!
billybiltit.blogspot.com/
www.kzrider.com/forum/5-chassis/325862-triple-tree-custom-work
kzrider.com/forum/5-chassis/294594-frame-bracing?limitstart=0
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- larrycavan
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Re: How do you fix broken fins on cylinder?
21 Mar 2011 18:31 - 21 Mar 2011 18:33Nelson wrote: No I didn't break any...
I sometimes see good used deals on performance piston kits with a matching cylinder, but it has a broken fin so noone buys it or it sells cheap. I might buy one of these if the repair is simple/cheap enough to do. The engine has to look right, I don't want busted stuff on it!
I don't weld aluminum, but I'm guessing a pro could easily weld on a piece of plate and then shape it to match. Actually I could do a nice job of the shaping myself, but I can't do the welding.
Does this sound like something that would be easy for a pro welder to do? Is there anything I'm overlooking?
Cylinder fins are small. That being the case you might consider getting one of those aluminum welding kits that use a torch. You would simply build up the broken area and grind it to shape. Kit's are not that expensive and will work for at least cosmetic repairs like that.
I tried those rods once on a broken pressure washer and the weld would not hold. After speaking to a pro welder I was informed that while it's not advertised, the rod has a shelf life. The rod I used was pretty old.
www.alumiweld.com/
Larry C
Last edit: 21 Mar 2011 18:33 by larrycavan.
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- stonemaster
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Re: How do you fix broken fins on cylinder?
21 Mar 2011 18:52+1 on the shelf life, i know some guys that keep rods in the refrigerator to increase their lifelarrycavan wrote:Nelson wrote: No I didn't break any...
I sometimes see good used deals on performance piston kits with a matching cylinder, but it has a broken fin so noone buys it or it sells cheap. I might buy one of these if the repair is simple/cheap enough to do. The engine has to look right, I don't want busted stuff on it!
I don't weld aluminum, but I'm guessing a pro could easily weld on a piece of plate and then shape it to match. Actually I could do a nice job of the shaping myself, but I can't do the welding.
Does this sound like something that would be easy for a pro welder to do? Is there anything I'm overlooking?
Cylinder fins are small. That being the case you might consider getting one of those aluminum welding kits that use a torch. You would simply build up the broken area and grind it to shape. Kit's are not that expensive and will work for at least cosmetic repairs like that.
I tried those rods once on a broken pressure washer and the weld would not hold. After speaking to a pro welder I was informed that while it's not advertised, the rod has a shelf life. The rod I used was pretty old.
www.alumiweld.com/
Larry C
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- Nelson
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Re: How do you fix broken fins on cylinder?
21 Mar 2011 22:08
cool, lots of ideas. I thought of the JB weld plan also, but it seems pretty redneck.. even for me.:laugh:
Restoring and customizing a KZ1000. Click here to read about it.
Plated KTM, DR650, KZ1000, Former MC mechanic (eons ago). 40 yrs. of dirt and street.
Plated KTM, DR650, KZ1000, Former MC mechanic (eons ago). 40 yrs. of dirt and street.
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- APE Jay
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Re: How do you fix broken fins on cylinder?
22 Mar 2011 00:39
Jim the welder at A1 Weldors in No.Hollywood is a genius. He does all of our fin repair. None better.
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- wireman
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Re: How do you fix broken fins on cylinder?
22 Mar 2011 01:21
Ztorch is actually the best in this part of the globe

posting from deep under a non-descript barn in an undisclosed location southwest of Omaha.
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