GSXR 750 1990 exhaust header

[justin]

Hi,

I have just joined the site and wondered if somebody had a GSXR 750 1990 and wouldn't mind checking a few points on their headers for me. I bought a GSXR 750 1990 last month and noticed the exhaust is touching the belly pan at 2 points. It might have an 1100 set of headers on, wrong link pipe or just a wrong exhaust. It also looks like the rear brake torque bar has been rewelded as doesn't quite look factory and the exhaust just touches it. If you do have one you can look at please could you answer the following.

1. Where the header enters the manifold mine stands proud by 1cm . This is due to the section after the flange measuring 2cm and it looks like the manifold only allows 1 cm to enter. Is yours flush?

2. I have a gap between sump and headers of about 2cm as well. Are your headers very close to the sump or do you have clear space like mine?

3. How much space do you have between the fairing by the RH footrest and the link pipe? Mine touches, do you have a small clearance or more like 1cm+?

Sorry for all the questions but I am trying to work out if all the exhaust is wrong or just the link pipe.

Not sure if my solution will be a new exhaust or dremmel the fairing where it touches. Tried looking for exhausts and they are not easy to find

Any help you can offer is gratefully received. I am down in Bath if anybody is in this neck of the woods.

Thanks

[Captain Chaos]

Standard 750L exhaust

no pics on bike since it has an 1100 engine now

[Captain Chaos]

And yes the brake torque arm is like that. 

[justin]

Thanks for the response captain chaos.

7 hours ago, Captain Chaos said:

Standard 750L exhaust

no pics on bike since it has an 1100 engine now

Thanks for the response. Yes my torque arm is just like yours. My headers are different to your standard version. Could you do me a favour when you get time and measure the diameter of your link pipe?

[Captain Chaos]

54mm

 

[justin]

Cheers Captsin Chaos, you're a star. My link pipe is 65mm or close to that and is of a totally different construction. Which means if I bought stock headers the Micron won't fit. Leaves me a few things to ponder to work out the best solution. I wonder what exhaust I have mmmm. Might try and locate drawings on the net but for sure it isn't a standard setup. I greatly appreciate you going to the effort of measuring them for me. Don't suppose you have a full Yoshi exhaust in the garage

[Captain Chaos]

when I bought the 750L (in 2003... time flies) it had a Yoshi slip-on, which is now modified to fit the B12 engined EFE.

Post some pics of the exhaust on your bike and we will probably be able to tell you what it is.

 

[justin]

Cheers, I will strip all the plastics next weekend and get some detailed pics posted with measurements. Will also keep an eye on Eblag as you never know your luck. The joy of buying old bikes

[martyngsxr]

sounds like you have a micron system on yours has the link pipe got a baffle/reducer welded in ive got a stainless micron system on mine and it touches the belly pan so i run it without ill post some pictures of mine later today 

 

[justin]

On 5/21/2020 at 10:22 AM, martyngsxr said:

sounds like you have a micron system on yours has the link pipe got a baffle/reducer welded in ive got a stainless micron system on mine and it touches the belly pan so i run it without ill post some pictures of mine later today 

 

Thanks for the reply. Where is the baffle / reducer inside the link pipe? Just before the end can ?

[justin]

Just now, justin said:

Thanks for the reply. Where is the baffle / reducer inside the link pipe? Just before the end can ?

My micron fits over the link pipe. The actual link pipe is 63mm dia going down to 41mm as it changes from 1 into 2.  My link pipe appears to be about 10mm larger than the OEM posted by Captain Chaos

[Gixer1460]

I'm guessing someone has fitted an 1100 system cos it fitted! If you want to keep the fairing then you need a 750 system - wrapped pipes will still melt / burn plastics - they still get f**kin hot, just not as hot as before! Respaced GSXR1000 K3 headers maybe a tighter fit but from the collector back is DIY territory!

[martyngsxr]

yeah the baffle is in the link pipe were the end can slips on 

 

[justin]

29 minutes ago, Gixer1460 said:

I'm guessing someone has fitted an 1100 system cos it fitted! If you want to keep the fairing then you need a 750 system - wrapped pipes will still melt / burn plastics - they still get f**kin hot, just not as hot as before! Respaced GSXR1000 K3 headers maybe a tighter fit but from the collector back is DIY territory!

Thanks, I will keep looking for the correct system. I might just have to buy in sections as I have located correct headers but need to find a decent link pipe and end can. I was thinking of cutting away parts of the fairing with a Dremel but going off that idea.

[justin]

31 minutes ago, martyngsxr said:

yeah the baffle is in the link pipe were the end can slips on 

 

Thanks, I will pop the end can off later today and take a look.

[justin]

Pics of the exhaust, can anybody identify the headers? Pretty sure the link pipe will be oil cooled Slingshot 1100. If the headers are simply the 1100 then that must make the manifold hole deeper on the 1100. Sorry I don't know the correct name Forgot to take the end can off to check for a baffle in the link pipe, bugger. I will pop it off during the week as it is beer time now.

[martyngsxr]

That definitely looks like the 750 system as all 4 pipes go to the right into the collector. As far as I'm aware the 1100 go 2 to the right of the sump and 2 to the left and then meet the collector behind the sump I'll add some pictures of mine camera not good on my phone though 

[justin]

4 hours ago, martyngsxr said:

That definitely looks like the 750 system as all 4 pipes go to the right into the collector. As far as I'm aware the 1100 go 2 to the right of the sump and 2 to the left and then meet the collector behind the sump I'll add some pictures of mine camera not good on my phone though 

Cheers that would be a help. My 4  section is 35mm dia,  2 - 1 section is a single piece. The 2 part is 42mm dia and 1 section 63mm. If it is a 750 section I wonder if it is for a water cooled rather than oil cooled. I'm not ruling out a Frankenstein mixed model headers and link pipe.

Edited May 25, 2020 by justin
extra detail

[justin]

17 hours ago, justin said:

Cheers that would be a help. My 4  section is 35mm dia,  2 - 1 section is a single piece. The 2 part is 42mm dia and 1 section 63mm. If it is a 750 section I wonder if it is for a water cooled rather than oil cooled. I'm not ruling out a Frankenstein mixed model headers and link pipe.

 

[justin]

Latest update on my exhaust journey. I have found out that Cobra still make a full stainless steel exhaust for my bike. There were a couple of choices and after much deliberation I ordered the S4 with name plate upgrade. They confirmed it will work with standard fairings and no alterations. I will post a full review when it arrives. The ordering process was great and the person in live chat super helpful. Lets see how fitting, quality and sound stack up. Once it arrives I will sell off my exhaust. If I can ID my current system it would be a huge help. 

[Crass]

Now the fun starts - getting the old headers off without snapping off the bolts in the head  (settles down with popcorn)...

[Fazz711]

Plenty of penetrant oil over a few days. 

 

[justin]

7 hours ago, Crass said:

Now the fun starts - getting the old headers off without snapping off the bolts in the head  (settles down with popcorn)...

I hope you don't mind if I try not to entertain you. I took 1 header off at the weekend to look at it and was rusty but only finger tight. However, we all know that was to lull me into a false sense of security. It will all go well until I get to that 1 bolt and then ......

[Gixer1460]

9 hours ago, Fazz711 said:

Plenty of penetrant oil over a few days. 

 

That's what I keep mentioning to SWMBO

[justin]

On 5/25/2020 at 7:05 AM, justin said:

Thanks for the reply. Where is the baffle / reducer inside the link pipe? Just before the end can ?

Yes, there is a baffle in the link pipe. The exhaust is in great condition and well made. It is a real shame it touches the plastics.