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General GS500 Discussion / Re: Crankshaft end float
« Last post by sledge on Today at 03:02:34 AM »
Maybe someone can chime in if just replacing the thrust bearing would be a feasible way to eliminate the problem.

Yeah.....I will, just give me a minute to look in my crystal ball and find my x-ray glasses   :thumb:
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General GS500 Discussion / one way air valve GS500F 2004
« Last post by bongler on Today at 02:56:32 AM »
Hi, please help. My Haynes manual shows a one way check valve ,in 3.11  picture 7.26d.    Mine is missing so where should it be please?
Thanks very much.
Regards,
Reg.
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General GS500 Discussion / Air check valve
« Last post by bongler on Today at 02:44:45 AM »
HI, where is the air check valve located please?
Thank you.
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General GS500 Discussion / Re: unable to post photos
« Last post by user11235813 on Today at 02:34:59 AM »
I'd recommend https://postimage.io no need to sign up or make an account just upload and you get a choice of codes for forum. Direct link or thumbnails.

Someone help!  I have attempted to post photos of my project but I get an error that says the board is full try a smaller photo or contact an administrator.  I'm posting small photos as it is.  What's the problem??
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General GS500 Discussion / Re: exhaust tuning discussion
« Last post by crackin on May 29, 2017, 09:33:08 PM »
Thanks for all the input guys, lots of good information here and lots to consider.
Midrange HP. Yea good luck with that. You're floating the valves ? what rpm does it run ?
I couldn't say exactly, as i dont have a tacho on the bike. Im bouncing valves in low gears simply from over revving the engine. The head has been fully rebuilt and im running 1mm oversize piston and rings. I'll stick the tacho on and see what revs they bounce at.
OK here are the figures I got for the GS500 using a readily available calculator.
Length of header FROM the valve face: 508mm/35mmID
Collector box:139mm
Tailpipe: 455mm/45mmID.
Overall pipe length before muffler FROM VALVE FACE: 1102mm
The big problem with the Gs is the 180deg cranks ANd the massive valve overlap that will occur because of it. This will screw op the waves arriving back at the ports ( and they will be severly assymmetric).
Here is an alternative I found for 180deg offset crank.
Header: 508mm/35mmID into 127mm/45mmID
The collector and tail the same as above.
Overall pipe length before muffler FROM VALVE FACE: 1229mm

For 2 single pipes:
From valve face header and tailpipe single pipe: 963mm/35mmID.
2 singles should give better peak HP and be shorter. If you choose very ligfht cans it will be Lighter.

Not sure which will give you more torque at mid/lower but suspect the 2 into 1 180deg crank design should.
These are theroybase figures. Proper dyno tuning is needed for optimium.

INTERESTINGLY there is a new maths set designed for non 360deg crank offsets that MotoGP( yamaha)  and Formula 1 motors are using with steps in the headers. But nobody is letting the formulae for these into public gaze. They would be perfect for this engine to get around the pulse interference and have nice short pipes with 2 into 1.

Thank for chimming in here gregjet, I know you have lots of race experience.
 Adding in the extra 127mm/45mmID is very interesting. I dont have a center stand so it should be doable on my machine. Still, I may need to go a little shorter on the primarys as the collector i'm going to make will be 200/250mm long and I may put a short cone on it too. Any idea what size the collect outlet should be?
  Johno
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General GS500 Discussion / Re: Crankshaft end float
« Last post by jamesf on May 29, 2017, 09:17:45 PM »
The gs has thrust bearings/washers to control the end play I according to parts diagrams. Which is why I'm wondering if it would be worth it for me to tear the engine down and just replace them. Problem is I assume that the crank would probly also need to be replaced and that would be more money than it would be worth. Maybe someone can chime in if just replacing the thrust bearing would be a feasible way to eliminate the problem.
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General GS500 Discussion / Re: Crankshaft end float
« Last post by ajensen on May 29, 2017, 08:34:06 PM »
I am really curious about this question. Sometimes, engines can run with a lot of crankshaft end play. For example, my old air-cooled Volkswagen Beetle was way out of  specs, but it ran thousands of miles that way and was still running great when I sold it. Of course it did not have a cam chain to worry about. Some two-strokes have cranks that float a certain amount, but they, of course, have ball bearings on the crankshaft. What does control crankshaft end play in a GS500 engine?
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Tard Farm / Re: THE nsfw three word game
« Last post by Janx101 on May 29, 2017, 07:45:23 PM »
He screamed and

Sent from my LG-K500 using Tapatalk

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General GS500 Discussion / Re: 1993 Bogging Down Unless Throttle is past 1/2
« Last post by Watcher on May 29, 2017, 06:56:30 PM »
If they're dirty they will.

Could also be a faulty needle/seat
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General GS500 Discussion / Re: Crankshaft end float
« Last post by jamesf on May 29, 2017, 05:36:21 PM »
Before I think about replacing the motor I wonder if I should tear it apart and see if I can just fix it by replacing the thrust bearing.
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