Wild Dog Adventure Riding

Technical Section => Make / Model Specific Discussions => Suzuki DR & DRZ => Topic started by: Matie spero on March 26, 2015, 10:25:52 am

Title: DR650 Exhaust question
Post by: Matie spero on March 26, 2015, 10:25:52 am
Ok this has been troubling me for a while now, it seems like my header pipe start to rust, but its more of a mud burnt onto the pipe.

it all seems to start from the top of the pipe and runs down the inside, most DR fotos posted I see the same thing happening.

what can cause this? leakage past the exhaust gasket???

Title: Re: DR650 Exhaust question
Post by: ChrisL - DUSTRIDERS on March 26, 2015, 10:48:39 am
Mud burns onto the header when it is hot.
Get yourself some Autosol and some elbowgrease. They will look new again. :deal:
Title: Re: DR650 Exhaust question
Post by: Matie spero on March 26, 2015, 11:10:18 am
Mud burns onto the header when it is hot.
Get yourself some Autosol and some elbowgrease. They will look new again. :deal:

yes, thanks the plan, just want to find out if theres not something specific that causes this...

I just find it strange where the mud is burning onto the pipe...

it really looks more like fluid running down the pipe, where mud then burns onto it......
Title: Re: DR650 Exhaust question
Post by: chopperpilot on March 26, 2015, 07:35:05 pm
The header pipe is stainless. Keep mine clean with some scotch brite!👍


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Title: Re: DR650 Exhaust question
Post by: lecap on March 27, 2015, 09:04:36 am
You can polish the (stainless) header but it will go brow after a while again. Oxidation of the stainless steel due to exposure to high temperature and atmospheric oxygen. There is only one way to avoid this: Double walled headers as found on most classic Jap. bikes
Title: Re: DR650 Exhaust question
Post by: ZA on March 27, 2015, 09:48:32 am
Ceramic coat dit. Jy kan dit self ook doen, solank jou vrou jou net nie vang terwyl jy die oond gebruik nie. Dit kan nogal moeilik wees om te verduidelik as daar n exhaust in die oond le. 
Title: Re: DR650 Exhaust question
Post by: Matie spero on March 27, 2015, 09:50:31 am
thanks all, for the advise on how to clean it, but it still does not answer my question:

is this due to some or other leakage past the exhaust gasket or something?
Form the picture you can see it's just on certain parts of the exhaust...
my first thoughts was it was like oil is running down from the top of the exhaust and mud is burning onto it....

if it was just due to heat or exposure, the entire pipe would start to go brown?
Title: Re: DR650 Exhaust question
Post by: Matie spero on March 27, 2015, 09:52:00 am
Ceramic coat dit. Jy kan dit self ook doen, solank jou vrou jou net nie vang terwyl jy die oond gebruik nie. Dit kan nogal moeilik wees om te verduidelik as daar n exhaust in die oond le. 

hahahaha glo my sal nie die vreemdste ding wees wat sy al ooit in die oond gesien het as sy by die huis kom nie...

ek DIY graag in ding.

hoe kan ek dit self doen?????
Title: Re: DR650 Exhaust question
Post by: ZA on March 27, 2015, 09:57:41 am
thanks all, for the advise on how to clean it, but it still does not answer my question:

is this due to some or other leakage past the exhaust gasket or something?
Form the picture you can see it's just on certain parts of the exhaust...
my first thoughts was it was like oil is running down from the top of the exhaust and mud is burning onto it....

if it was just due to heat or exposure, the entire pipe would start to go brown?


http://dr650.wikia.com/wiki/Potential_problems_to_be_aware_of (http://dr650.wikia.com/wiki/Potential_problems_to_be_aware_of)

"Also inspect the header pipe for any hairline cracks which cause exhaust leaks."
Title: Re: DR650 Exhaust question
Post by: ZA on March 27, 2015, 10:02:16 am
Ceramic coat dit. Jy kan dit self ook doen, solank jou vrou jou net nie vang terwyl jy die oond gebruik nie. Dit kan nogal moeilik wees om te verduidelik as daar n exhaust in die oond le. 

hahahaha glo my sal nie die vreemdste ding wees wat sy al ooit in die oond gesien het as sy by die huis kom nie...

ek DIY graag in ding.

hoe kan ek dit self doen?????

http://www.akmicorp.com/ceramic-coating-do-it-yourself-basics/ (http://www.akmicorp.com/ceramic-coating-do-it-yourself-basics/)

Youtube is jou beste vriend ook  :biggrin:
Title: Re: DR650 Exhaust question
Post by: Matie spero on March 27, 2015, 10:18:50 am
Ceramic coat dit. Jy kan dit self ook doen, solank jou vrou jou net nie vang terwyl jy die oond gebruik nie. Dit kan nogal moeilik wees om te verduidelik as daar n exhaust in die oond le. 

hahahaha glo my sal nie die vreemdste ding wees wat sy al ooit in die oond gesien het as sy by die huis kom nie...

ek DIY graag in ding.

hoe kan ek dit self doen?????

http://www.akmicorp.com/ceramic-coating-do-it-yourself-basics/ (http://www.akmicorp.com/ceramic-coating-do-it-yourself-basics/)

Youtube is jou beste vriend ook  :biggrin:

Thanks ZA!!!!!!!!!!!!!
Title: Re: DR650 Exhaust question
Post by: Black_Hawk on March 27, 2015, 10:37:35 am
Mud burns onto the header when it is hot.
Get yourself some Autosol and some elbowgrease. They will look new again. :deal:

+1.
Autosol and plenty of elbow grease is the way to go.
Title: Re: DR650 Exhaust question
Post by: 2wdrift on March 29, 2015, 11:02:04 am
thanks all, for the advise on how to clean it, but it still does not answer my question:

is this due to some or other leakage past the exhaust gasket or something?
Form the picture you can see it's just on certain parts of the exhaust...
my first thoughts was it was like oil is running down from the top of the exhaust and mud is burning onto it....

if it was just due to heat or exposure, the entire pipe would start to go brown?


As mens die pyp afhaal en skoonmaak is daar gewoonlik geen roes om die pyp nie, dis net modder wat 'n baksteen word om jou uitlaatpyp. Die plekke waar dit aanpak is gewoonlik die dele waar mens nie maklik kan was nie.

Op myne was die voorkant van die pyp ook baie meer skoon omdat ek baie sand pad ry en die voorwiel sand opskiet, amper die pyp sandblast.
Title: Re: DR650 Exhaust question
Post by: chopperpilot on March 29, 2015, 04:23:29 pm
Hier is myne, met Scotch Brite skoongemaak.😉(http://tapatalk.imageshack.com/v2/15/03/29/614c54bf6874df9bd756ddfa6884ada4.jpg)


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Title: Re: DR650 Exhaust question
Post by: Matie spero on March 30, 2015, 02:00:57 pm
thanks all, for the advise on how to clean it, but it still does not answer my question:

is this due to some or other leakage past the exhaust gasket or something?
Form the picture you can see it's just on certain parts of the exhaust...
my first thoughts was it was like oil is running down from the top of the exhaust and mud is burning onto it....

if it was just due to heat or exposure, the entire pipe would start to go brown?


As mens die pyp afhaal en skoonmaak is daar gewoonlik geen roes om die pyp nie, dis net modder wat 'n baksteen word om jou uitlaatpyp. Die plekke waar dit aanpak is gewoonlik die dele waar mens nie maklik kan was nie.

Op myne was die voorkant van die pyp ook baie meer skoon omdat ek baie sand pad ry en die voorwiel sand opskiet, amper die pyp sandblast.

Thanks, ek het die header gister af gehaal, sal vanaand n foto neem, dit lyk stteds vir my verdag, mar dit maak sin.
Title: Re: DR650 Exhaust question
Post by: Matie spero on March 31, 2015, 02:19:16 pm
thanks all, for the advise on how to clean it, but it still does not answer my question:

is this due to some or other leakage past the exhaust gasket or something?
Form the picture you can see it's just on certain parts of the exhaust...
my first thoughts was it was like oil is running down from the top of the exhaust and mud is burning onto it....

if it was just due to heat or exposure, the entire pipe would start to go brown?


As mens die pyp afhaal en skoonmaak is daar gewoonlik geen roes om die pyp nie, dis net modder wat 'n baksteen word om jou uitlaatpyp. Die plekke waar dit aanpak is gewoonlik die dele waar mens nie maklik kan was nie.

Op myne was die voorkant van die pyp ook baie meer skoon omdat ek baie sand pad ry en die voorwiel sand opskiet, amper die pyp sandblast.

Thanks, ek het die header gister af gehaal, sal vanaand n foto neem, dit lyk stteds vir my verdag, mar dit maak sin.


Ok ek het n foto van die header van n beter angel af, verstaan nou hoekom dit vir my lyk asof daar iets teen die pyp afloop....
Title: Re: DR650 Exhaust question
Post by: Matie spero on March 31, 2015, 02:28:20 pm
so klein bietjie staalwol gevolg deur autosol, maar net op klein stukkie, nog nie tyd gehaad om werklik te doen nie....

plus my autosol applicator wou nie vir lank saam werk nie...
Title: Re: DR650 Exhaust question
Post by: chopperpilot on March 31, 2015, 02:47:40 pm
Goeie werk! Lyk netjies! :thumleft:

Asbakkies mooi leeg gemaak! :imaposer: :thumleft:
Title: Re: DR650 Exhaust question
Post by: Kykdaar on March 31, 2015, 03:45:52 pm
[quote

Asbakkies mooi leeg gemaak! :imaposer: :thumleft:
[/quote]

 :laughing4: ja, het ook daai opgelet.

Net jammer hyt nou sy kamera staan en breek
Title: Re: DR650 Exhaust question
Post by: Matie spero on April 20, 2015, 12:17:20 pm
ok, so alles is nou mooi skoon en oppad terug vanaand.

Twee vragies:
1) Sal julle aanraai dat ek copperslip op die boude sit wat die header pyp aan die head vas maak?
2) Die Splinter nuwe OEM muffler gasket wat ek gekoop het is presies die selfde buite diameter as die FMF pyp, so dit gaan nie werk nie.
    waste ander opsies is daar om daai seel daar te kry, het laas gungum gebruik... miskien heat resistant silicon?

Title: Re: DR650 Exhaust question
Post by: Woestynhond on April 20, 2015, 12:25:49 pm
copperslip sal nie skade doen nie, beter as om die stud af te draai v roes... n stukkie van die geweefde veselglas wat met high heat silicone  gesmeer is en droog laat word het om die header pyp sal werk.....
Daai header gaannie lank mooi blink bly nie so hou op om makeup aan die fiets te sit en gaan maak hom eerder vuil in die modder!.... ;D
Title: Re: DR650 Exhaust question
Post by: Matie spero on April 20, 2015, 12:55:30 pm
copperslip sal nie skade doen nie, beter as om die stud af te draai v roes... n stukkie van die geweefde veselglas wat met high heat silicone  gesmeer is en droog laat word het om die header pyp sal werk.....
Daai header gaannie lank mooi blink bly nie so hou op om makeup aan die fiets te sit en gaan maak hom eerder vuil in die modder!.... ;D

baie dankie vir die advies!!!!! ek sal doen soos jy voor gestel het buide met die copper slip en di glasvesel en silicon.

vir die res:

Ek het die bike 2 en n bietjie jaarterug gekoop, van toe af het ek haar net soos n slet behandel!!!!! olie en lugvultertjie is altyd mooi versorg, maar ekt haar gery soos n goedkoop slet.

so nou sit ek net bietjie pampelang in want syt gedreig om te loop....
so een van die dae is sy weer mooi en lief vir my....
net om twee jaar later weer gepamperlang te word!

Title: Re: DR650 Exhaust question
Post by: chopperpilot on April 20, 2015, 01:49:51 pm
Ek smeer net 'n lagie silicon, waar die FMF aan die header pyp pas.


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Title: Re: DR650 Exhaust question
Post by: Morokai on April 21, 2015, 07:28:29 am
ok, so alles is nou mooi skoon en oppad terug vanaand.

Twee vragies:
1) Sal julle aanraai dat ek copperslip op die boude sit wat die header pyp aan die head vas maak?
2) Die Splinter nuwe OEM muffler gasket wat ek gekoop het is presies die selfde buite diameter as die FMF pyp, so dit gaan nie werk nie.
    waste ander opsies is daar om daai seel daar te kry, het laas gungum gebruik... miskien heat resistant silicon?



Ek het gum gum gebruik om my FMF pyp aan te heg. werk soos n bom
Title: Re: DR650 Exhaust question
Post by: Matie spero on April 21, 2015, 08:36:11 am
Ek het die vorige keer ook gun gum gebruik.

toe het die pyp gekraak, nie a.g.v. die gun gum nie, maar ek kon nie vas stel of ek n 100% seel gehaad het nie.

Chopper:
sukkel mens nie erg om die silicon weer af te kry as jy weer die pyp afhaal nie?

die gungum het eintelik bitter maklik af gekom. +1
Title: Re: DR650 Exhaust question
Post by: lecap on April 21, 2015, 09:05:47 am
ok, so alles is nou mooi skoon en oppad terug vanaand.

Twee vragies:
1) Sal julle aanraai dat ek copperslip op die boude sit wat die header pyp aan die head vas maak?
2) Die Splinter nuwe OEM muffler gasket wat ek gekoop het is presies die selfde buite diameter as die FMF pyp, so dit gaan nie werk nie.
    waste ander opsies is daar om daai seel daar te kry, het laas gungum gebruik... miskien heat resistant silicon?



I am not quite sure if I got the first question. You should definitely use copper compound on the bolts that hold the header on the cylinder head. Also replace the crush gasket when ever you had the header pipe off. I like to use a bit of copper compound on the crush gasket too, prevents it from sticking on the aluminium of the cylinder head the next time you disassemble.
And don't forget to torque the header pipe bolts again after one or two rides or they WILL come loose.

The second question: Unfortunately many aftermarket exhaust manufacturers think the OEM gaskets for the silencer connector are useless rubbish. Their gasket less direct slip on systems in fact are the rubbish as they are almost always leaking to varying degrees, either don't clamp at all or are near impossible to detach after having been fitted for a longer period of time. Sealing with gun gum or silicone is problematic (besides looking shite) as the gun gum will sooner or later crack and the silicone will burn - besides from none of the products actually being able to seal INSIDE the cylindrical connection.
Common problems caused by loose or leaking silencer connections are gas grilled rear shocks and holes burned into air boxes (commonly found on KLR's) and vibration cracks in silencer shells and mounting brackets.
Title: Re: DR650 Exhaust question
Post by: Matie spero on April 21, 2015, 09:29:14 am
ok, so alles is nou mooi skoon en oppad terug vanaand.

Twee vragies:
1) Sal julle aanraai dat ek copperslip op die boude sit wat die header pyp aan die head vas maak?
2) Die Splinter nuwe OEM muffler gasket wat ek gekoop het is presies die selfde buite diameter as die FMF pyp, so dit gaan nie werk nie.
    waste ander opsies is daar om daai seel daar te kry, het laas gungum gebruik... miskien heat resistant silicon?



I am not quite sure if I got the first question. You should definitely use copper compound on the bolts that hold the header on the cylinder head. Also replace the crush gasket when ever you had the header pipe off. I like to use a bit of copper compound on the crush gasket too, prevents it from sticking on the aluminium of the cylinder head the next time you disassemble.
And don't forget to torque the header pipe bolts again after one or two rides or they WILL come loose.

The second question: Unfortunately many aftermarket exhaust manufacturers think the OEM gaskets for the silencer connector are useless rubbish. Their gasket less direct slip on systems in fact are the rubbish as they are almost always leaking to varying degrees, either don't clamp at all or are near impossible to detach after having been fitted for a longer period of time. Sealing with gun gum or silicone is problematic (besides looking shite) as the gun gum will sooner or later crack and the silicone will burn - besides from none of the products actually being able to seal INSIDE the cylindrical connection.
Common problems caused by loose or leaking silencer connections are gas grilled rear shocks and holes burned into air boxes (commonly found on KLR's) and vibration cracks in silencer shells and mounting brackets.

Thanks lecap, you got both questions 100%

will use the coper slip, have the new crush casket, and will tighten after first two rides.

on the muffler seal, what I take from what you said is:
1) OEM gasket si shit en in my case does not fit.
2) Gungum will crack and looks shit.
3) silicon will burn, and looks like shit.

so what would you recommend for the seal, or are you saying I should not seal at all?
Title: Re: DR650 Exhaust question
Post by: lecap on April 22, 2015, 10:20:07 am
...

so what would you recommend for the seal, or are you saying I should not seal at all?

Ideally modify the exhaust to take the OEM gasket. If you use the OEM header and a slip on with a connector pipe it should be no more than a simple chop off and weld job although it might be a bit of a mission to find the correct diameter tubing. (You might have to roll and weld it from a piece of sheet).

Next best is just fit it "dry" without anything. Make sure it does not blow against the air box or shock. Comes with all the disadvantages mentioned earlier.
Title: Re: DR650 Exhaust question
Post by: Matie spero on April 22, 2015, 11:12:00 am
...

so what would you recommend for the seal, or are you saying I should not seal at all?

Ideally modify the exhaust to take the OEM gasket. If you use the OEM header and a slip on with a connector pipe it should be no more than a simple chop off and weld job although it might be a bit of a mission to find the correct diameter tubing. (You might have to roll and weld it from a piece of sheet).

Next best is just fit it "dry" without anything. Make sure it does not blow against the air box or shock. Comes with all the disadvantages mentioned earlier.

great stuff thanks!!!

if I was still in Struisbaai, I would have modified the exhaust...

but trying to get that done here in PTA after all the driving around to get other parts and sorting out other shit on her, not gonna happen!!!
every mission is a 1:30 round trip to drop off an then again to collect...

I will continue to search for something in the line of a thin asbestos gasket that will fit.

what about that cloth people use to wrap their exhausts????


Title: Re: DR650 Exhaust question
Post by: Serfie on April 22, 2015, 03:21:40 pm
"Oxidation of the stainless steel due to exposure to high temperature and atmospheric oxygen. There is only one way to avoid this: Double walled headers as found on most classic Jap. bikes" - lecap



Aw thanx lecap...mine is exactly the same and I haven't been through mud in ages...nothing to worry about then...
Title: Re: DR650 Exhaust question
Post by: Serfie on April 22, 2015, 03:28:00 pm
but trying to get that done here in PTA after all the driving around to get other parts and sorting out other shit on her, not gonna happen!!!
every mission is a 1:30 round trip to drop off an then again to collect...



Welcome to Gauteng Matie...I have had nearly 17 years of that, BUT soon that will change when I move to Kleinmond!!! What did you do at Struisbaai?...also far removed from bigger areas?
Title: Re: DR650 Exhaust question
Post by: Matie spero on April 22, 2015, 03:48:06 pm
but trying to get that done here in PTA after all the driving around to get other parts and sorting out other shit on her, not gonna happen!!!
every mission is a 1:30 round trip to drop off an then again to collect...



Welcome to Gauteng Matie...I have had nearly 17 years of that, BUT soon that will change when I move to Kleinmond!!! What did you do at Struisbaai?...also far removed from bigger areas?

that where I spent my youth!!!! til 5 years ago, moved uphere.
Title: Re: DR650 Exhaust question
Post by: Matie spero on April 24, 2015, 10:28:38 am
ok so I have also done the header weld grind that every one is talking about.

then when I wanted to refit the header is saw that the header port hole itself is quite smaller than the inlet to the header pipe.
in the photo below I put the crush gasket back, the gasket is the same size as the header pipe.

now the question:
Grinding down the weld does not remove any obstruction as the actual port is smaller then the weld reduced the header pipe.
what is your thoughts on doing "port matching" between the header pipe and the header i.e. also grind the port hole a bit open to almost match the header pipe?
Title: Re: DR650 Exhaust question
Post by: Matie spero on April 24, 2015, 10:31:46 am
here's an example of what I am refereeing to:
Title: Re: DR650 Exhaust question
Post by: chopperpilot on April 24, 2015, 02:38:43 pm
Sal graag die DR performance gurus se opinies hieroor wil hoor! :thumleft:

Ek self gaan nie daar karring nie. Dalk eendag as die enjin moet oop! ;)

Title: Re: DR650 Exhaust question
Post by: Kykdaar on April 24, 2015, 04:21:30 pm
Sal graag die DR performance gurus se opinies hieroor wil hoor! :thumleft:

Ek self gaan nie daar karring nie. Dalk eendag as die enjin moet oop! ;)



Ja, behalwe as daar n blob welding daar in die pad hang hang gaan  ek ook nie die grinder ding doen nie.
Title: Re: DR650 Exhaust question
Post by: pielas on April 24, 2015, 04:50:13 pm
I know very little about porting and the nitty-gritty of airflow dynamics, but do know that when working in ports the opposite of what you might expect is often true.  Your argument to get rid of the ridge makes sense , and as such I would be very careful before proceeding.

Bigger is not always better ( velocity decrease), a mirror finish is not better than  as a rough one ( laminar flow), Wave dynamics, are affected by the lenth of the port, conrod angle, etc

Rather have an expert on this have a look at it. My XR 650 R was "gas flowed" by Tim Basson by the previous owner and it made a big difference. To do porting successfully you will need an air-flow bench and a solid understanding of the principles involved. This is a specialist job, and mainly done by people who do it and it only.

I know you dont want to do a whole porting exercise, but working in there is a "dark art"and can easily do more harm than good. If you decide to go through with it, please do it after the dyno, and we can do a dyno afterwards again and compare graphs. I will contribute half of the R's for the after dyno.  :thumleft:
Results should be interisting, .

Edit: spelling
Title: Re: DR650 Exhaust question
Post by: chopperpilot on April 24, 2015, 05:49:08 pm
As die exhaust port so klein is, help dit dan enigsins om die header weld te grind, behalwe as jy natuurlik 'n vol gas flow op die head doen.


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Title: Re: DR650 Exhaust question
Post by: lecap on April 25, 2015, 08:46:54 am
You should only grind the weld's end blob (if there is a significant one), not the whole bead. Grinding the bead weakens the weld significantly.
Title: Re: DR650 Exhaust question
Post by: Matie spero on April 28, 2015, 10:33:50 am
I know very little about porting and the nitty-gritty of airflow dynamics, but do know that when working in ports the opposite of what you might expect is often true.  Your argument to get rid of the ridge makes sense , and as such I would be very careful before proceeding.

Bigger is not always better ( velocity decrease), a mirror finish is not better than  as a rough one ( laminar flow), Wave dynamics, are affected by the lenth of the port, conrod angle, etc

Rather have an expert on this have a look at it. My XR 650 R was "gas flowed" by Tim Basson by the previous owner and it made a big difference. To do porting successfully you will need an air-flow bench and a solid understanding of the principles involved. This is a specialist job, and mainly done by people who do it and it only.

I know you dont want to do a whole porting exercise, but working in there is a "dark art"and can easily do more harm than good. If you decide to go through with it, please do it after the dyno, and we can do a dyno afterwards again and compare graphs. I will contribute half of the R's for the after dyno.  :thumleft:
Results should be interisting, .

Edit: spelling

Hi Pielas

You are 100% right that I do NOT WANT TO DO A PORTING exercise.

I will try and make contact with a professional and ask him this question, as it (in my mind) makes sence to grind it open a bit.

but I hear your comments about the bigger not always better and velocity getting lost...




Title: Re: DR650 Exhaust question
Post by: Matie spero on April 28, 2015, 10:36:15 am
As die exhaust port so klein is, help dit dan enigsins om die header weld te grind, behalwe as jy natuurlik 'n vol gas flow op die head doen.


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Chopper

Dit is 100% hoekoem ek die vraag gevra het. ek het fotos gesien op die interwebs waar daar werlik baie groot obstructive blobs is, maar in 99% van die geval is dit nie so nie, en dan maak dit nie veel sin om die weld weg te grind nie.

Title: Re: DR650 Exhaust question
Post by: Matie spero on April 28, 2015, 10:39:38 am
You should only grind the weld's end blob (if there is a significant one), not the whole bead. Grinding the bead weakens the weld significantly.

Lecap
I did not have a significant blob, but also did not grind the weld away completely, left about 1mm there still.

agree that this could be the hottest part of the exhaust and would require a proper weld for structural integrity.

Title: Re: DR650 Exhaust question
Post by: chopperpilot on April 28, 2015, 10:45:26 am
As die exhaust port so klein is, help dit dan enigsins om die header weld te grind, behalwe as jy natuurlik 'n vol gas flow op die head doen.


Sent from my iPad using Tapatalk

Chopper

Dit is 100% hoekoem ek die vraag gevra het. ek het fotos gesien op die interwebs waar daar werlik baie groot obstructive blobs is, maar in 99% van die geval is dit nie so nie, en dan maak dit nie veel sin om die weld weg te grind nie.


:thumleft:
Title: Re: DR650 Exhaust question
Post by: Kykdaar on April 28, 2015, 11:08:20 am
No blob = no grind.

Now go and put your bike together so we can go for a ride ;D
Title: Re: DR650 Exhaust question
Post by: Matie spero on April 28, 2015, 11:55:07 am
Heres an interesting read:

http://drriders.com/topic2360-30.html (http://drriders.com/topic2360-30.html)
Title: Re: DR650 Exhaust question
Post by: Matie spero on April 28, 2015, 11:56:26 am
No blob = no grind.

Now go and put your bike together so we can go for a ride ;D

as dit van my af gehang het was sy al lankal aan mekaar...

dis n fyn balanseerings oeffening tussen haar, mamma gelukkig hou en tyd....
Title: Re: DR650 Exhaust question
Post by: lecap on April 29, 2015, 09:31:02 am
Heres an interesting read:

http://drriders.com/topic2360-30.html (http://drriders.com/topic2360-30.html)

What scares me about this article is that the author does not see a gasket even if he takes a VERY clear picture of it ::)

If you're really that hot in pursuit of some extra power you should maybe DIR and cut the flange off the header below the clamping ring, machine a new flange on the lathe with an inner diameter matching the port and then TIG weld it back on from the outside. If you do this right you will have a 100% quality strong weld with no significant protrusion to the inside and very little protrusion to the outside. The problem with the OEM weld is it's MIG and done from the inside likely for cost reasons.
Grinding around on a weld is a no no. It's kind of acceptable to clean off an over sized end blob. As long as it's not a structural weld.
Title: Re: DR650 Exhaust question
Post by: Matie spero on April 29, 2015, 12:27:09 pm
here's also something interesting:
but requires an extreme technical knowledge:

http://dairally.net/daihard/chas/MiscCalculators/DaiPipes.htm (http://dairally.net/daihard/chas/MiscCalculators/DaiPipes.htm)

and some more (I found this probably the most useful):

http://hotrodenginetech.com/porting-pointers/ (http://hotrodenginetech.com/porting-pointers/)

anybody keen to do some maths????????