Author Topic: Throttle cable slack adjustment & Question about restrictor plates  (Read 366 times)

Offline crackin

  • Trade Count: (0)
  • Formula Extreme Racer
  • ***
  • Posts: 240
  • Karma: +3/-0
Re: Throttle cable slack adjustment & Question about restrictor plates
« Reply #20 on: August 06, 2018, 09:08:53 AM »
Wow thats a hell of a lot of cash to drop on a carb service. I know mechanics charge like a wounded bull, but that would be near $400 aus dollars. You could buy an ultrasonic cleaner for 200 pounds where you are. Then you could clean your carbs when ever you liked.
 The slide insert's probably weren't entirely necessary, but if the mechanic has a good reputation as Sledge suggests, then he ain't gonna risk sending you the carb's back half done. He just charge's you for the part's and labour.
 Your running a stock air box and filter right? Maybe raise the E clip on the jet needles a notch if she's bogging.
 And pull those restrictors out. Your mechanic would not have set up your carbs the way he did if he knew they where in there.
« Last Edit: August 06, 2018, 10:32:33 AM by crackin »
No matter what i do to it, it's still a GS
 It's not how fast your bike is, it's how long you are prepared to hold the throttle on.

Offline sledge

  • Trade Count: (+2)
  • Motorcycle God!
  • ******
  • Posts: 4265
  • Karma: +42/-0
  • He's Mr Brightside
Re: Throttle cable slack adjustment & Question about restrictor plates
« Reply #21 on: August 06, 2018, 10:45:20 AM »
Break the costs down.
It was 60 for labour, the rest being parts and postage.

When you consider certain top flight franchised dealers in parts of the UK are now charging upwards of 75/hour + VAT at 20% it seems fair price to me, especially when you consider the calibre of the guy.




Offline Toner

  • Trade Count: (0)
  • Formula Extreme Racer
  • ***
  • Posts: 243
  • Karma: +1/-0
Re: Throttle cable slack adjustment & Question about restrictor plates
« Reply #22 on: August 06, 2018, 01:35:52 PM »
Wow thats a hell of a lot of cash to drop on a carb service. I know mechanics charge like a wounded bull, but that would be near $400 aus dollars. You could buy an ultrasonic cleaner for 200 pounds where you are. Then you could clean your carbs when ever you liked.
 The slide insert's probably weren't entirely necessary, but if the mechanic has a good reputation as Sledge suggests, then he ain't gonna risk sending you the carb's back half done. He just charge's you for the part's and labour.
 Your running a stock air box and filter right? Maybe raise the E clip on the jet needles a notch if she's bogging.
 And pull those restrictors out. Your mechanic would not have set up your carbs the way he did if he knew they where in there.

You know I think the issue I had may have been with the slide guides. You can see the issue I was having in this vid.
The choke wasn't working properly like the valves were sticking. I'd also stall out when stopped at lights unless I put the choke up but not every time.
He sent the old carb slides back so I'll post some pics later to see what you think.

« Last Edit: August 06, 2018, 01:37:30 PM by Toner »

Offline mr72

  • Trade Count: (0)
  • World Superbike Racer
  • *****
  • Posts: 1783
  • Karma: +27/-0
  • Musician, Engineer, Sci-Fi Author
    • Josh's Books
Re: Throttle cable slack adjustment & Question about restrictor plates
« Reply #23 on: August 06, 2018, 04:03:24 PM »
I think the 117.5 jets were sized to work with the restrictor plates in place. If you remove the restrictor plates, the 120 jets may wind up making it too lean, but you can sort that out yourself down the line. 122.5 or 125 jets were stock without restrictor plates.

FYI.

Offline sledge

  • Trade Count: (+2)
  • Motorcycle God!
  • ******
  • Posts: 4265
  • Karma: +42/-0
  • He's Mr Brightside
Re: Throttle cable slack adjustment & Question about restrictor plates
« Reply #24 on: August 06, 2018, 06:00:47 PM »
Given he has just had the carbs overhauled by one of the best guys in the UK I think he should leave everything well alone but if he does have an issue speak to the man himself for advice.......don't you?

FYI

These are the stock main jet sizes for UK models.

EK&EP 120
ER&ES 125 (LH) 122.5 (RH)
ET to EY 115
K1 and on 115

It's all there in black and white in the service manual  :thumb:

Maybe you should get yourself a copy and read though it rather than saying things that just aren't true and giving out misleading info.

BTW.....have you ever even seen a restricted GS5?

Offline Toner

  • Trade Count: (0)
  • Formula Extreme Racer
  • ***
  • Posts: 243
  • Karma: +1/-0
Re: Throttle cable slack adjustment & Question about restrictor plates
« Reply #25 on: August 06, 2018, 08:59:18 PM »
Mine's an EY model. I do wonder whether removing the restrictor plates would impact what jets are best and whether the manual takes that into account.
I took her out again with a full tank today up the mountains. No issues again. No bogging, no stalling so I'm happy with it.

Here's some pics of the old sliders. 










Offline crackin

  • Trade Count: (0)
  • Formula Extreme Racer
  • ***
  • Posts: 240
  • Karma: +3/-0
Re: Throttle cable slack adjustment & Question about restrictor plates
« Reply #26 on: August 06, 2018, 09:03:47 PM »
Break the costs down.
It was 60 for labour, the rest being parts and postage.

When you consider certain top flight franchised dealers in parts of the UK are now charging upwards of 75/hour + VAT at 20% it seems fair price to me, especially when you consider the calibre of the guy.

 Yep, that sounds reasonable i guess. The main thing is Toner has piece of mind that the carbs are "tip top".
I think the 117.5 jets were sized to work with the restrictor plates in place. If you remove the restrictor plates, the 120 jets may wind up making it too lean, but you can sort that out yourself down the line. 122.5 or 125 jets were stock without restrictor plates.

FYI.

 I don't think the restrictor plates are going to make any difference to how the carbs mix the air/fuel ratio. It doesn't matter how much suction there is at the intake, the air/fuel mixture at the carbs will be reasonably constant. You just won't be able to make full power.
 I could be wrong though. My DR-Z had a similar restrictor, I just took it out and there was no need for a re-jet. But boy did the power output increase.
No matter what i do to it, it's still a GS
 It's not how fast your bike is, it's how long you are prepared to hold the throttle on.

Offline crackin

  • Trade Count: (0)
  • Formula Extreme Racer
  • ***
  • Posts: 240
  • Karma: +3/-0
Re: Throttle cable slack adjustment & Question about restrictor plates
« Reply #27 on: August 06, 2018, 09:10:47 PM »
Mine's an EY model. I do wonder whether removing the restrictor plates would impact what jets are best and whether the manual takes that into account.
I took her out again with a full tank today up the mountains. No issues again. No bogging, no stalling so I'm happy with it.

Here's some pics of the old sliders. 

 They look pretty normal to me, mine are worse looking than those.
 Good to hear she's running well.
 Now all that's left to do is remove those darn restrictors and throw them in the ocean lol
No matter what i do to it, it's still a GS
 It's not how fast your bike is, it's how long you are prepared to hold the throttle on.

Offline Toner

  • Trade Count: (0)
  • Formula Extreme Racer
  • ***
  • Posts: 243
  • Karma: +1/-0
Re: Throttle cable slack adjustment & Question about restrictor plates
« Reply #28 on: August 06, 2018, 09:48:30 PM »
Mine's an EY model. I do wonder whether removing the restrictor plates would impact what jets are best and whether the manual takes that into account.
I took her out again with a full tank today up the mountains. No issues again. No bogging, no stalling so I'm happy with it.

Here's some pics of the old sliders. 

 They look pretty normal to me, mine are worse looking than those.
 Good to hear she's running well.
 Now all that's left to do is remove those darn restrictors and throw them in the ocean lol

They're already out, lol. Don't think I'll be throwing them in the ocean when I see them going for 60 on ebay. 
https://www.ebay.com/itm/Suzuki-GS-500-F-Restrictor-Kit-35kW-46-46-6-46-9-47-bhp-DVSA-RSA-Approved/321483435521

Offline sledge

  • Trade Count: (+2)
  • Motorcycle God!
  • ******
  • Posts: 4265
  • Karma: +42/-0
  • He's Mr Brightside
Re: Throttle cable slack adjustment & Question about restrictor plates
« Reply #29 on: August 07, 2018, 07:03:20 AM »
When the restrictor plates were fitted there will have been a certificate issued by the authorised installer, it will have included the VIN and reg numbers and acted as proof to the police and insurance company that. the machine has actually been restricted. Unlikely anyone will want to buy them if they don't have the certificate, without it they are useless.

There are a few ways to restrict a GS5, the plates you have are the most common, probably because they are quick and easy to fit. I have removed several from bikes I sold in the past. Can't say I ever saw one restricted in this way that was not jetted as stock as part of the restriction. They don't effect the carb settings, they limit how much mixture enters the engine.

Interestingly, some restriction kits are now tamperproof

https://www.morebikes.co.uk/14360/anti-tamper-device-deter-riders-illegally-derestricting-moped-motorcycle/
« Last Edit: August 07, 2018, 07:08:38 AM by sledge »

Offline Toner

  • Trade Count: (0)
  • Formula Extreme Racer
  • ***
  • Posts: 243
  • Karma: +1/-0
Re: Throttle cable slack adjustment & Question about restrictor plates
« Reply #30 on: August 07, 2018, 01:22:11 PM »
That's interesting Sledge, cheers.

Offline mr72

  • Trade Count: (0)
  • World Superbike Racer
  • *****
  • Posts: 1783
  • Karma: +27/-0
  • Musician, Engineer, Sci-Fi Author
    • Josh's Books
Re: Throttle cable slack adjustment & Question about restrictor plates
« Reply #31 on: August 07, 2018, 02:00:30 PM »
Since they affect both vacuum and air velocity, restrictor plates like this will directly affect mixture.

Offline sledge

  • Trade Count: (+2)
  • Motorcycle God!
  • ******
  • Posts: 4265
  • Karma: +42/-0
  • He's Mr Brightside
Re: Throttle cable slack adjustment & Question about restrictor plates
« Reply #32 on: August 07, 2018, 05:41:49 PM »
A restriction to flow in the inlet tract means the carb slides wont rise as high as they would without the restriction. There will still be mixture there and in the correct ratio just not as much, in the same way it would be with a part open throttle.

Coincidentally this is how Suzuki themselves restrict the bike, not by the use of plates but by limiting how far the slides can travel in the body.

This really is simple stuff and I am somewhat surprised the theory behind all this never occurred to you what with you considering yourself to be a GS5 carb expert and all that  :D

Offline mr72

  • Trade Count: (0)
  • World Superbike Racer
  • *****
  • Posts: 1783
  • Karma: +27/-0
  • Musician, Engineer, Sci-Fi Author
    • Josh's Books
Re: Throttle cable slack adjustment & Question about restrictor plates
« Reply #33 on: August 07, 2018, 06:40:48 PM »
A restriction to flow in the inlet tract means the carb slides wont rise as high as they would without the restriction.

I think that's where you are making your error.

Quote
what with you considering yourself to be a GS5 carb expert and all that  :D

You keep saying this, but you do realize it's only you who says this, right?

Look, Toner, I'm happy to help if I can as I am sure dozens of others on this forum are. But Sledge is not helping you, so I strongly suggest you double check everything he says. For that matter, you should double-check everything I say, and everything any other amateur home motorcycle mechanic on this forum says, because as well-meaning as we might all be, many of us are learning this along with you and make mistakes along the way. Sledge can and does often know what he's talking about, he just doesn't know how to talk to people like a human being and he can't seem to tell when he's wrong.

Offline sledge

  • Trade Count: (+2)
  • Motorcycle God!
  • ******
  • Posts: 4265
  • Karma: +42/-0
  • He's Mr Brightside
Re: Throttle cable slack adjustment & Question about restrictor plates
« Reply #34 on: August 07, 2018, 07:22:38 PM »
I have seen you interfering again and telling Toner he may have a problem but seen nothing from Toner to suggest he actually has one its quite the opposite in fact. Not have I seen him asking for help or advice. If that changes all he needs to do is contact the very knowledgable and experienced  person who did the work on his carbs and discuss it with him, the same person who you are questioning and undermining and has forgotten more about motorcycle carbs than you are ever likely to know.  Not  listen to someone on the other side of the world who has no experience whatsoever of restricted GS5s and the setting up of UK spec carbs and who up until 2 years ago had never even seen the inside of a GS5 carb and in fact only recently realised his was full of non standard parts.

Hows that for sensible advice  :thumb:
« Last Edit: August 07, 2018, 08:21:58 PM by sledge »

Offline sledge

  • Trade Count: (+2)
  • Motorcycle God!
  • ******
  • Posts: 4265
  • Karma: +42/-0
  • He's Mr Brightside
Re: Throttle cable slack adjustment & Question about restrictor plates
« Reply #35 on: August 08, 2018, 09:34:52 AM »
Some more sensible advice. This is taken from the factory service manual and describes how our carbs operate.

 "" The carburetor is a variable venturi type. The venturi cross sectional area is increased or decreased automatically by the piston valve which moves according to negative pressure present in the downstream  side of the venturi. Negative pressure is admitted into the diaphragm chamber through 2 orifices provided in the piston valve" "

 "" Rising negative pressure overcomes the spring force causing the piston valve to rise to increase the said area and thus prevent the air velocity from increasing. This air velocity in the venture passage is kept constant for improved fuel atomization and for securing the optimum ratio of fuel air mixture" "

So......in simple terms......
 
The height or distance the slides (piston valves) move is dependant on the amount of vacuum (negative pressure) downstream of the venturi (inlet tract). It therefore stands to reason that  if there is a restriction that limits the amount of negative pressure, say from a restrictor plate, the slides will not rise as high. Furthermore because the air velocity in the venturi remains constant regardless  of the position of the slide the mixture ratio remains optimum.
It's just the amount of mixture delivered that changes.


Again....it's all there in black and white  :dunno_black:

Error?
Me?


Errr...I don't think so  :D
« Last Edit: August 08, 2018, 09:44:56 AM by sledge »

Offline qcbaker

  • Trade Count: (0)
  • World Supersport Racer
  • *****
  • Posts: 975
  • Karma: +11/-0
Re: Throttle cable slack adjustment & Question about restrictor plates
« Reply #36 on: August 08, 2018, 12:33:01 PM »
This forum: *mentions carburetor parts*

Sledge:


Offline Toner

  • Trade Count: (0)
  • Formula Extreme Racer
  • ***
  • Posts: 243
  • Karma: +1/-0
Re: Throttle cable slack adjustment & Question about restrictor plates
« Reply #37 on: August 12, 2018, 07:45:10 PM »
Well, I can't comment on this disagreement as I my knowledge of carbs is limited. I would like to thank you both for helping me though.
This forum has been very kind to me and is my favourite thing about owning a GS so I don't like this thread being the cause of a conflict. 
My second favourite thing about owning a GS is taking it on long rides in the mountains so here's a few pics from my last trip.
Cheers guys. Bike is still running great.  :)







Offline Suzuki Stevo

  • Zippy Handy Warmy
  • Trade Count: (0)
  • World Superbike Racer
  • *****
  • Posts: 1929
  • Karma: +18/-0
  • GS500FK7 Blue & White
Re: Throttle cable slack adjustment & Question about restrictor plates
« Reply #38 on: August 14, 2018, 01:21:41 AM »
Changing the ability to breath, does not change the mixture....Point Sledge  :cheers:
I Ride: at a speed that allows me to ride again tomorrow AN400K7, 2016 TW200, Boulevard M50, 2018 Indian Scout, 2018 Indian Chieftain Classic