A forum for owners of Yamaha TTR250 trail and enduro bikes!

jasparach · Senior Member

Left hand generator cover material

TTRfan · Super Guru

It must be an alloy of some sort as I have had two cracked covers successfully TIG welded.

Brian

barra8 · Guru

jasparach wrote:
Does anyone know what material the lefthand generator/starter cover
is made from, does anyone know if it can be welded where it cracks inside
around the starter motor?

It's a cast aluminium & as Brian says it can be welded athough not as easy as this sounds. If it's not too big you could use selleys Kneed-it but up to you.

.......................

Jarrah.

BM Steve · Guru

Most Japanese engine casings are made from Magnesium Alloy, yes you can weld them using TIG or Oxy / Acetaline if you have access to or know anyone with a DHC-2000 Welding and Cutting Torch, like mine biggrin

In Aus http://www.amweld.com.au/

barra8 · Guru

BM Steve wrote:
Most Japanese engine casings are made from Magnesium Alloy, yes you can weld them using TIG or Oxy / Acetaline if you have access to or know anyone with a DHC-2000 Welding and Cutting Torch, like mine

In Aus http://www.amweld.com.au/

Aha thats what i was thinking of but it won't matter either way..Same process for welding.

............

Jarrah.

jasparach · Senior Member

Thanks lads, that's what i wanted to know that it can be done
and someone has done it.

barra8 · Guru

fabspec wrote:
You guys are kidding right? Recommending welding magnesium using Oxy-Acetylene equipment is a bit dangerous. Although it can be done-generally with liberal use of the right flux, I would bet the novice welder would promptly oxidize the crap out of it, then start a fire he could not extinguish. Best to hold out for a proper TIG repair.

Umm okay lets see...

jasparach wrote:

Does anyone know what material the lefthand generator/starter cover

is made from, does anyone know if it can be welded where it cracks inside

around the starter motor?

Brian wrote:

.....................................................................................................................................

It must be an alloy of some sort as I have had two cracked covers successfully TIG welded.

Brian

...................................................................................................................................

Barra8 wrote:

It's a cast aluminium & as Brian says it can be welded athough not as easy as this sounds. If it's not too big you could use selleys Kneed-it but up to you.

.......................................................................................................................................................................................

BM Steve wrote:
Most Japanese engine casings are made from Magnesium Alloy, yes you can weld them using TIG or Oxy / Acetaline if you have access to or know anyone with a DHC-2000 Welding and Cutting Torch, like mine

In Aus http://www.amweld.com.au/
.........................................................................................................................................................................................................
At no stage did we reccommend using Oxy-Acetylene equipment.......
As you can see i said this is not as easy as it is written. We were assuming he will be getting someone else to do it as he did'nt know this could be done.
Any person competent at welding can carry out a job like this without drama so we merely told him it can be done & how.
By the way here is a (half-hearted) welcome to the forum
..................................

Jarrah.

-- Edited by barra8 on Friday 9th of November 2012 05:43:42 PM

fabspec · Newbie

You guys are kidding right? Recommending welding magnesium using Oxy-Acetylene equipment is a bit dangerous. Although it can be done-generally with liberal use of the right flux, I would bet the novice welder would promptly oxidize the crap out of it, then start a fire he could not extinguish. Best to hold out for a proper TIG repair.

barra8 · Guru

Maybe you need to know more about welders eg... From the link Steve gave above...

Welding Equipment & Supplies, Australia


6 REASONS TO BUY THE AUSTRALIAN INVENTED DHC 2000 OXY/ACETYLENE WELDING & CUTTING TORCH INSTEAD OF STANDARD OXY TORCH, MIG OR TIG


# 1 - The narrow concentrated flame of the DHC 2000 allows you to weld the very thinnest material with minimum distortion

GAS MIXING OPERATION OF THE DHC 2000 WITH NARROW CONCENTRATED HEAT & OXYGEN FREE ENVIRONMENT IN THE WELDING AREA.


			DHC 2000




THE STANDARD OXY TORCH HAS THE OPPOSITE, A WIDE HEAT SPREAD, OXIDISATION & HIGH VELOCITY





			THE STANDARD OXY TORCH



# 2 - The DHC 2000 has a unique internal mixing chamber that creates an oxygen free environment around the weld area just like a TIG, this also creates low flame velocity for more control.









# 3 - WELDS STRONGER THAN TIG (see test results for aluminium & stainless)


# 4 - Welds anything a MIG or TIG will weld, but with more pliability & no MIG splatter, great for Car Restorers in thin panel steel. (see tafe test here)



# 5 - Cuts from the thinnest panel steel up to 25mm like a plasma cutter. Welds steel to 12mm



# 6 - Uses less than half the gas of a standard oxy torch.

barra8 · Guru

fabspec wrote:
You guys are kidding right? Recommending welding magnesium using Oxy-Acetylene equipment is a bit dangerous. Although it can be done-generally with liberal use of the right flux, I would bet the novice welder would promptly oxidize the crap out of it, then start a fire he could not extinguish. Best to hold out for a proper TIG repair.

People like you annoy me Here we are helping people out of the good of our heart,asking nothing in return apart from a little RESPECT.& you come along & think you know everything all of a sudden...Sorry to tell you this but you are'nt talking to amatuers that think they know what they are doing! If you want to find those guys there is plenty of other forums for you to put your two cents in (suggestion: www.weldingsolutionsforamatuers.com :)

Sorry to be honest but mate....We aint kids on here & don't need to be treated like kids.

I'm pretty sure everyone else will feel the same way ashamed

................

Jarrah.

-- Edited by barra8 on Saturday 10th of November 2012 07:29:24 AM

TTRfan · Super Guru

Good luck with the repair John - let us know how it goes. Pics are always good wink

When you take it for welding make sure that you take along the starter gear cover and bolts as anything to stop the weld distortion will help. You might have to do a bit of filing when it comes back.

Brian

PS The pics below show the sort of damage a worn sprag can cause.

Damaged casing and gears2.jpg

Damaged casing and gears1.jpg

jasparach · Senior Member

iI will go with the TIG weld on the case as Brian has already said that
he has had two done successfully so it's worth trying it at least. I know that it
can be difficult to do given the material but you pays your money and takes
your chances as the man said.

jasparach · Senior Member

The gear teeth on mine are all looking ok ; ie as in the one shown in the
second pic, am in the process of making a flywheel holder so as to get the flywheel
off and see what the rest looks like. The crack in my cover is not quite as big as that
i think said he hopefully. The starter pinion is quite worn down on the outer edge
where it engages the gears so i would presume that the sprag will
be in the same condition; ie as in having to be replaced. They were done as i said
before i bought the bike but that is 10 years ago. I will try and post some photos
as i go.

Thanks Brian for the photos.

John

jasparach · Senior Member

Cover and what appeared to me to be a crack, once i cleaned it with kerosene it doesn't seem to be cracked, is it possible that oil can seep through the o ring on the starter cover. The other pictures show the sprag clutch and gear wheels. Does that sprag seem worn to anyoneor what should the profile of the teeth on a new one look like?

jasparach · Senior Member

not a great pic of the starter motor area but no cracks that i can see at any rate

TTRfan · Super Guru

You may be lucky. My cracks were fairly obvious and caused by trauma i.e. broken gear tooth/teeth catching between the gears and cracking the casing. If your gears are all in one piece it seems unlikely that the casing has been cracked.

If the sprag is "banging" then I heartly recommend you don't take a chance and replace it whilst everything is apart and your starter gears and casing are still in one piece!

Rebuild carefully with a new gasket and everything clean so that you will more easily spot the source of any oil leak.

Brian

barra8 · Guru

An appoligy will not be given to Fabspec,although i would like to appoligize to all on this forum for having to put up with unsightly stuff like a few posts above. I think that this forum is awesome & all members so far (given one exception) have been great. I am so glad to be part of such a caring,helpfull,friendly forum & would like to keep it that way. Keep up the good work all and remember...KEEP IT REAL wink

..................

Jarrah.

barra8 · Guru

Thought i'd clean this up as it says pretty much the same thing below...

Appoligy to jasparach for hi-jackn his thread.

.............

Jarrah.

-- Edited by barra8 on Monday 12th of November 2012 09:05:21 AM

barra8 · Guru

If you have'nt noticed this is a forum for TTR owners not know it alls that like to google or rocket scientists. wink We are all (usually) calm & collective,helpfull people... What got me was how you just join & then all of a sudden trying to make us all look like idiots. eg...

FABSPEC wrote:

You guys are kidding right? Recommending welding magnesium using Oxy-Acetylene equipment is a bit dangerous. Although it can be done-generally with liberal use of the right flux, I would bet the novice welder would promptly oxidize the crap out of it, then start a fire he could not extinguish. Best to hold out for a proper TIG repair.

__________________

FABSPEC wrote:

First and foremost, I do apologize if I have offended anyone. However, as barra8 has seen fit to go ballistic, I will embellish on my original response.

I have more certifications than barra8 has extraneous parts on his body (that includes ears, nose and eyelashes).

If any of you are in my area, I’ll be more than happy to talk to any of you. I’ll even buy - Even for barra8.

Fabspec - OUT

..................................................................................................................................................................................................

I'll have you know there are some very smart mechanics on here & i am no exception. Also nobody on this forum was...... Recommending welding magnesium using Oxy-Acetylene equipment is a bit dangerous''.

Steve wrote:

Most Japanese engine casings are made from Magnesium Alloy, yes you can weld them using TIG or Oxy / Acetaline if you have access to or know anyone with a DHC-2000 Welding and Cutting Torch, like mine biggrin

In Aus http://www.amweld.com.au/

__________________

Which would be perfectly fine to use Did you click on the link above??? Guess not!

If you would like to share some of your ideas & thoughts on welding ect. please do so but making someone look dumb for something your wrong about aint on in my book. Sure enough it is dangerous but we like danger on here wink All this said a tig would be best for the job. Thats not to say there are not other methods to this & if they work they don't seem dumb to me.

.....................

Jarrah.

-- Edited by barra8 on Monday 12th of November 2012 09:21:41 AM

fabspec · Newbie

Okay, since this keeps coming up, I feel a little explanation is in order on my part. First and foremost, I do apologize if I have offended anyone. However, as barra8 has seen fit to go ballistic, I will embellish on my original response.

I have been welding 45 years, the last 30+ years on man-rated rocket systems. Space Shuttle engines since their inception and now the current system. I weld more X-ray quality aluminum, magnesium and other alloys than most people have ever heard of, daily. I have trained hundreds and hundreds of welders through my years (yes on my own systems at home), free of charge. I have more certifications than barra8 has extraneous parts on his body (that includes ears, nose and eyelashes). I have never taken a cent for my efforts outside of my daily job. I hire welders and train them daily. I think I can handle your TTR problems.

You have a new member in my area, he is welcome to visit me and report back to you – an un-biased opinion. Your toy weld equipment will get somebody hurt trying to weld magnesium – why do you think they have outlawed magnesium wheels in racing? If any of you are in my area, I’ll be more than happy to talk to any of you. I’ll even buy - Even for barra8.

Fabspec - OUT

brindabella · Senior Member

yeah, ok, ok... but does anyone actually KNOW how much (if any) magnesium is in those aluminium alloy cases?

The only thing I know is that both magnesium powder and aluminium powder can make excellent solid rocket fuel,
when combined with ammonium perchlorate - but I guess that's not relevant

barra8 · Guru

brindabella wrote:
yeah, ok, ok... but does anyone actually KNOW how much (if any) magnesium is in those aluminium alloy cases?

The only thing I know is that both magnesium powder and aluminium powder can make excellent solid rocket fuel,
when combined with ammonium perchlorate - but I guess that's not relevant

I do not claim to be a rocket sceintist on this subject but this is what the encylopedia says...

Practically all the commercial magnesium alloys manufactured in the United States contain aluminum (3 to 13 per cent) and manganese (0.1 to 0.4 per cent). Many also contain zinc (0.5 to 3 per cent) and some are hardenable by heat treatment. All the alloys may be used for more than one product form, but alloys AZ63 and AZ92 are most used for sand castings, AZ91 for die castings, and AZ92 for most used for permanent mold castings (AZ63 and A10 are sometimes used). For forgings, AZ61 is most used, with M1 employed where low strength is required and AZ80 for highest strength. For extrusions, a wide range of shapes, bars, and tubes is made from M1 alloy where it’s low strength suffices or where welding to M1 castings is planned. Alloys AZ31, AZ61, and AZ80 are employed for extrusions in the order named, where their increase in strength justifies their increased cost.^[1]

Magnox (alloy), whose name is an abbreviation for 'magnesium non-oxidising', is 99% magnesium and 1% aluminium, and used in the cladding of fuel rods in some nuclear power stations.

Magnesium alloys tend to be referred to by short codes (defined in ASTM 275) denoting the approximate chemical composition by weight: for example, AS41 has 4% aluminium and 1% silicon; AZ81 is 7.5% aluminium and 0.7% zinc. If aluminium is present, manganese is almost always also there at about 0.2% by weight to improve grain structure; if aluminium and manganese are absent, zirconium is usually present at about 0.8% for the same purpose

-- Edited by barra8 on Tuesday 13th of November 2012 12:21:59 AM

barra8 · Guru

Wheres that rocket scientist when you need him to do the maths aye ??? biggrin

.............

Jarrah.

A forum for owners of Yamaha TTR250 trail and enduro bikes!

TO BUY THE AUSTRALIAN INVENTED DHC 2000 OXY/ACETYLENE WELDING & CUTTING TORCH INSTEAD OF STANDARD OXY TORCH, MIG OR TIG

# 1 - The narrow concentrated flame of the DHC 2000 allows you to weld the very thinnest material with minimum distortion

GAS MIXING OPERATION OF THE DHC 2000 WITH NARROW CONCENTRATED HEAT & OXYGEN FREE ENVIRONMENT IN THE WELDING AREA.

DHC 2000

THE STANDARD OXY TORCH HAS THE OPPOSITE, A WIDE HEAT SPREAD, OXIDISATION & HIGH VELOCITY

THE STANDARD

OXY TORCH

# 2 - The DHC 2000 has a unique internal mixing chamber that creates an oxygen free environment around the weld area just like a TIG, this also creates low flame velocity for more control.

# 3 - WELDS STRONGER THAN TIG

# 4 - Welds anything a MIG or TIG will weld, but with more pliability & no MIG splatter, great for Car Restorers in thin panel steel.

# 5 - Cuts from the thinnest panel steel up to 25mm like a plasma cutter. Welds steel to 12mm

# 6 - Uses less than half the gas of a standard oxy torch.