Date: 29-03-24  Time: 07:30 am

Author Topic: Exhaust Down Pipes Question  (Read 3011 times)

YamFazFan

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Exhaust Down Pipes Question
« on: 03 February 2018, 07:29:42 pm »
What purpose do these screws, one in each down pipe, serve?.

Thanking you all kindly :)

« Last Edit: 14 November 2020, 07:58:05 pm by YamFazFan »

fazersharp

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Re: Exhaust Down Pipes Question
« Reply #1 on: 03 February 2018, 07:47:36 pm »
Often wondered that myself but have been too embarrassed to ask
I think their main roll is to rust themselves stupid
I wonder is it is something to do with factory set up - like when you attach hoses to your carbs to balance the carbs, or like a lot of stuff on the FZS 600 it has something to do with the bike they were first designed for
I don't do rain or threat there of. dry rider only with no shame.

YamFazFan

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Re: Exhaust Down Pipes Question
« Reply #2 on: 03 February 2018, 07:53:55 pm »
More modern bikes would have a lambda sensor there wouldn't they?.


unfazed

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Re: Exhaust Down Pipes Question
« Reply #3 on: 03 February 2018, 08:07:01 pm »
Setting the CO2 levels at the factory

YamFazFan

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Re: Exhaust Down Pipes Question
« Reply #4 on: 03 February 2018, 08:43:11 pm »
Thanks Unfazed.

I thought the FZS 600 was prior to the first phase of emission law though?.

That's why they all had to be registered by the June/July of 2003 wasn't it?.

fazersharp

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Re: Exhaust Down Pipes Question
« Reply #5 on: 03 February 2018, 09:34:34 pm »
Thanks Unfazed.

I thought the FZS 600 was prior to the first phase of emission law though?.

That's why they all had to be registered by the June/July of 2003 wasn't it?.
My first off the production line 98 has them if that helps -------- or not.
There was a tread like this a while back about that funny hole in the front fender with a bung in it and it turned out to be because the fender was from another bike that had a cable run through it. Maybe same thing here - the downpipes were for another bike
I don't do rain or threat there of. dry rider only with no shame.

unfazed

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Re: Exhaust Down Pipes Question
« Reply #6 on: 03 February 2018, 09:41:47 pm »
Nothing to do with emissions just to set up the individual carbs correctly, a bit of fine tuning

Most emission checks are at the  end of the exhaust which assumes the individual the carbs/throttle bodies are set correctly, getting an incorrect reading will tell you there is a problem but wont tell you which cylinder, that will require further investigation

YamFazFan

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Re: Exhaust Down Pipes Question
« Reply #7 on: 03 February 2018, 10:37:52 pm »
Good info.

Did many other bikes of that era have the same set up for CO2 testing?.



tommyardin

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Re: Exhaust Down Pipes Question
« Reply #8 on: 03 February 2018, 11:02:18 pm »
My understanding of the FZS600 was that it was a budget bike brought out because Honda and Suzuki had 600 4's, Yamaha had nothing really to compete sports touring wise, with that so the FZS 600 was born, again it's only what I have heard and read in a variety of places, Yamaha looked in the store room and found bits that they had an abundance of and used those parts, why else would a budget bike have the one of the best sets of front brakes on the market, the Multi Pot Blue Spots?


No decent mono shocks in stock, so manufacture an inferior cheap shock and nail that on, along with a not very satisfactory rear caliper, along with a few other dated looking components.


Painted down pipe and collector that rust again a bit on the cheap side, but, its a budget bike brought out in a hurry to compete with machines that were grabbing the mid range market.
I don't know, but, could the down-pipes also of be from old stock? I have heard that the Lump in the FZS 600 is a de-tuned R6 or ThunderCat mill. I often wondered if the welded threaded stubs on the down-pipes were ever designed to have a perhaps chrome shied to cover the black pipes just maybe they could be a fixing point for them.
I don't know and I am just speculating, it's a thought.
I bet when Yamaha launched the FZS600 back in 98 little did they know what a huge success that bike would be, or what a huge following it would have, the machine really is a legend in its life time.


Now I don't know if any of the stuff I have written here holds water or not, but it's ideas I have picked up from others and have read.     
« Last Edit: 03 February 2018, 11:04:04 pm by tommyardin »

tommyardin

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Re: Exhaust Down Pipes Question
« Reply #9 on: 03 February 2018, 11:08:08 pm »
Nothing to do with emissions just to set up the individual carbs correctly, a bit of fine tuning

Most emission checks are at the  end of the exhaust which assumes the individual the carbs/throttle bodies are set correctly, getting an incorrect reading will tell you there is a problem but wont tell you which cylinder, that will require further investigation


I have to say though that this does make sense. so my theory becomes just that foolish speculation lol.
Oh well if the hat fits :lol

unfazed

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Re: Exhaust Down Pipes Question
« Reply #10 on: 04 February 2018, 12:11:26 am »
My understanding of the FZS600 was that it was a budget bike brought out because Honda and Suzuki had 600 4's, Yamaha had nothing really to compete sports touring wise, with that so the FZS 600 was born, again it's only what I have heard and read in a variety of places, Yamaha looked in the store room and found bits that they had an abundance of and used those parts, why else would a budget bike have the one of the best sets of front brakes on the market, the Multi Pot Blue Spots?


No decent mono shocks in stock, so manufacture an inferior cheap shock and nail that on, along with a not very satisfactory rear caliper, along with a few other dated looking components.


Painted down pipe and collector that rust again a bit on the cheap side, but, its a budget bike brought out in a hurry to compete with machines that were grabbing the mid range market.
I don't know, but, could the down-pipes also of be from old stock? I have heard that the Lump in the FZS 600 is a de-tuned R6 or ThunderCat mill. I often wondered if the welded threaded stubs on the down-pipes were ever designed to have a perhaps chrome shied to cover the black pipes just maybe they could be a fixing point for them.
I don't know and I am just speculating, it's a thought.
I bet when Yamaha launched the FZS600 back in 98 little did they know what a huge success that bike would be, or what a huge following it would have, the machine really is a legend in its life time.


Now I don't know if any of the stuff I have written here holds water or not, but it's ideas I have picked up from others and have read.     

You are right in all the rest  :thumbup

unfazed

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Re: Exhaust Down Pipes Question
« Reply #11 on: 04 February 2018, 12:23:14 am »
Good info.

Did many other bikes of that era have the same set up for CO2 testing?.
Quite  a few including the Fazer 1000, Thundercat, ThunderAce, Fzr600, R6 Carb ver, YZF750R, R1 Carb ver, I am sure there were more, mostly late 90s early 2000s

celticdog

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Re: Exhaust Down Pipes Question
« Reply #12 on: 04 February 2018, 02:00:08 am »
Yes it was all the range back before the millennium, everything went emissions crazy, catalytic converter in cars etc. Yamaha obviously felt the need to pay for the extra nuts, I don't believe they where only for fine tuning, I suspect they a anticipated future use.
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unfazed

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Re: Exhaust Down Pipes Question
« Reply #13 on: 04 February 2018, 12:26:02 pm »
How would you fine tune the pilot circuit of the carbs without CO2 testers? This is the only adjustable point of the individual carbs, all other parts are fixed by design. Technically the only true way to set up carburetors properly including jet setting and needles is by checking  the CO2 levels at different revs.
Mike (Falcon269) and I and probably many others have noticed they must have forgotten to do it with the FZS1000 as the pilot screws were a bit erratic to say the least in their set up.
Not sure how well know it is, but the the last of the FZS1000s the 1C2 models were left out of the factory with the TPS setting and carb synchronising set incorrectly.
« Last Edit: 04 February 2018, 11:41:11 pm by unfazed »

stet

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Re: Exhaust Down Pipes Question
« Reply #14 on: 04 February 2018, 06:57:56 pm »
Good info.

Did many other bikes of that era have the same set up for CO2 testing?.
Quite  a few including the Fazer 1000, Thundercat, ThunderAce, Fzr600, R6 Carb ver, YZF750R, R1 Carb ver, I am sure there were more, mostly late 90s early 2000s

The Yam FZS1000 service manual does list them as 'Emission Check Bolt' (4 of), but the Yam FZS600 service manual is not so specific, although it does list some exhaust bolts which probably have the same function.
« Last Edit: 04 February 2018, 07:09:19 pm by stet »