Port repair

[djr]

Mick D, "with respect" as you say, this thread is about welding a CZ barrel not a Maico barrel ,
 and yes we all know the difference between pure aluminium and aluminium alloys ,
I doubt the alloy used in the CZ is exactly the same as Maico or any other manufacturer so you wont know how it welds until you try.
 when selecting an alloy to use for a casting I don't know if weldability is considered by the manufacturer or not, but I doubt it
many aluminium alloys are not recommended to be welded but we all ignore that when repairing or modifying old bike parts, sometimes they weld up nicely, sometimes it gets messy.
would you please explain the new welding process you say you have invented ?
I am always interested in new inventions but I haven't got a Maico, will it work on other bikes ?

[80-85 husky]

a mate stripped his sump plug on his new 85 kdx 200 (years ago) and in getting it welded up, the cases peeled apart and it looked like half a coke can was layered in the cases. Kawasaki stumped up some new cases.

[Mick D]

a mate stripped his sump plug on his new 85 kdx 200 (years ago) and in getting it welded up, the cases peeled apart and it looked like half a coke can was layered in the cases. Kawasaki stumped up some new cases.

That doesn't surprise me Husky Man,,, none of that Jap stuff seems to be up to Maico Quality
They even bought a few to spy on and still could come close guess that's what happens when you cut corners

[Mick D]

Mick D, "with respect" as you say, this thread is about welding a CZ barrel not a Maico barrel ,
 and yes we all know the difference between pure aluminium and aluminium alloys ,
I doubt the alloy used in the CZ is exactly the same as Maico or any other manufacturer so you wont know how it welds until you try.
 when selecting an alloy to use for a casting I don't know if weldability is considered by the manufacturer or not, but I doubt it
many aluminium alloys are not recommended to be welded but we all ignore that when repairing or modifying old bike parts, sometimes they weld up nicely, sometimes it gets messy.

No, no  Pretty obvious that I was clearly responding to the comments about "Castings being more difficult to weld",,,which is a total load of bolocks
Welding aluminium alloys ease or degree of difficulty mostly depends upon the composition of the parent metal!

would you please explain the new welding process you say you have invented ?
I am always interested in new inventions but I haven't got a Maico, will it work on other bikes ?

I just bought some new "maintenance repair items" for this process last week, still some more on the way


I can already replace them near "flawlessly". Maicos are easy because the Radial fin configuration allows better access than tight parallel fins. It is a pain to have to remove upper of lower fins to access the one that needs to be replaced or repaired. I was able to get in tight and replace the last Maico one without removing anything above or below with the tools I developed. I want to try a Parallel alloy fin next without removing above or below for access
I will post before and after and maybe in between pics,,,,soon I am hoping, but it is gingle bells time and I am in jingle bells mode until the new year

[Mick D]

you say

No, no, Have

[djr]

mick D, if you are going to quote me then quote the words I actually wrote don't make things up

I did not say - "castings are difficult to weld"
I actually said - " if that barrel is SAND CAST they don't always weld nicely due to some SAND getting into the casting"
try reading properly first before commenting

moulding sand can sometimes mix with the liquid metal if the pouring speed is too fast or the sand is weak/thin in places, this is not a problem until one day you decide to weld the casting and hit an area where there is some contamination, over a 25 year period I have had many sand cast aluminium parts welded and every decent welder I have been too has mentioned this potential problem
 

[Mick D]

mick D, if you are going to quote me then quote the words I actually wrote don't make things up

I did not say - "castings are difficult to weld"
I actually said - " if that barrel is SAND CAST they don't always weld nicely due to some SAND getting into the casting"
try reading properly first before commenting

Who said I was quoting you? Well? At least your self inflating
DH

[Mick D]

Make things up, F--- y-- DH

[Mick D]

Well come on, show me where I was quoting you when I made that first post! come on DH

[Mick D]

would you please explain the new welding process you say you have invented ?

What would be the point in that?

over a 25 year period I have had many sand cast aluminium parts welded and every decent welder I have been too has mentioned this potential problem

According to you,,,you wouldn't even be able to apply it? would you? so what would you do with my intellectual property? dispute it with nothing more than so called  "here say" ability? because you are unable to weld yourself? DH

[djr]

question - what would I do with your intellectual  property ?

answer - nothing, you don't seem to have any

[djr]

would you please explain the new welding process you say you have invented ?

What would be the point in that?

over a 25 year period I have had many sand cast aluminium parts welded and every decent welder I have been too has mentioned this potential problem

According to you,,,you wouldn't even be able to apply it? would you? so what would you do with my intellectual property? dispute it with nothing more than so called  "here say" ability? because you are unable to weld yourself? DH

its a bit hard to understand you here , are you trying to say the 10+ qualified welders who have mentioned potential sand contamination in sand castings to me  are all wrong ?
and that this is just  "here say" ?
is that what you are trying to say , because that's how it comes across ?

you also say    "because you are unable to weld yourself "?
I can weld fine with MIG, TIG, ARC, Oxy , but I choose to delegate some sand casting repairs to other people

[sa63]

I have been told by a (very good) welder the jap al. castings have a lot of zinc in them which makes the metal flow better during the casting process. When he welds them he takes his time "burning off" impurities, whether from the initial casting or later contamination. All done with a water cooled tig torch.
He crack tests afterwards as well. Also has a mini torch for ports/ valve pockets etc.

For sure every manufacturer has their own blend for castings

[tony27]

The welding will probably get done by the engine rebuild guys who bored the cylinder for me. They did some welding & machining on another cylinder for me a while ago & made a good job of it
I don't plan on getting full depth of the port welded, just 1 or runs(5-10mm) wide to allow me to taper from the sealing surface back to the rest of the port.

[fred99999au]

Personally, Tony, I'd be backing away from the welding right about now.