Valve Adjustment Documentation?

[koolaid_kid]

I haven't seen any references to bench testing the needle and/or seats before. I bench synced them to make sure the butterfly valves were open more or less the same amount (they were). Near the end of the carb teardown tutorial by Nessism, he's got the carb hooked up to test the floats - same test?

If you are speaking of page 62 of his Mikuni_BS-CV_Carburetor_Rebuild_Tutorial.pdf, the answer is yes, that is actually two tests in one, as he mentions. You are testing for float level height and to insure the needle and seat are working properly. He words it "to make sure your floats are sealing" which has the same meaning in different words.

[sedelen]

Well, I never thought I would manage it - feel free to laugh, those of you who do this for fun every other weekend - but the carbs have been dipped and reassembled and there aren't any parts left over!

I can relate to that, never done this on the bikes, but for outboard motors, just chucked the extra parts over my shoulder and hoped for the best, no problem o.

[jinkside]

Heck yeah. Give it a go. Don't let a couple pops scare you... If it continues popping- I'd confirm my ignition timing and coil connections to be sure they haven't been wired wrong. My GS450 has coil connections which can't be mixed up. Yours may be similar.

On your recommendation, I gave it another go and, 'lo and behold, it started right up.

Thanks, I had nearly given up on her.

This is slightly confusing. Where did the fuel leak out from?

I wasn't able to track it down exactly, but it was almost definitely from the carbs. It only did it when it was set to prime, so I wasn't too worried.

[Mekanix]

One reason for that test is to see how well your float needles are sealing.

On prime you are letting full pressure of the fuel in the tank push on the needle and if they are leaking you will get gas coming out of the vent tubes or needle jet and leaking out of the carb.

When running you are also letting the same amount of pressure out and the only reason it might not be leaking then is because the vibrations are helping the needle to seat.

You can replace the needle and seats or try and polish them with a Q-tip in a drill and metal polish.

[jinkside]

Okay, so it looks like the leak almost certain came from my vacuum tube connector. It was on super tight and took about ten minutes with pliers of yanking to remove, but after soaking everything in carb dip, it now slides on and off with little to no resistance. I set the petcock to prime and sat and watched it for a few minutes and gas only came from the vacuum tube, which I currently have disconnected to drain the horrible six-month-old, Seafoam-saturated gas out of my tank.

[jinkside]

Fun new problem: Hoping to save time of disconnecting/reconnecting the fuel hose from carbs, I set the petcock to prime and let it drip out the vacuum hose. Looking back, I'm not entirely certain why I didn't just remove the tank, but... hindsight, 20/20, etc.

So... now the left (lower) cylinder appears to be not firing, and fuel drips/sprays out of the exhaust near the footpeg. I grabbed a new spark plug since the old ones needed to be replaced so badly. I was hoping that would work, but no dice. Any suggestions?

Update:
When I went out to try it again a few minutes ago, I was able to get some white smoke. I think I may have gas in my oil from my prime-to-empty-the-tank mistake.

Second Update:
After having changed the oil - which was more fuel than oil at this point - I had some spotty performance, which I later realized was due to being out of fuel. A full tank later, my bike sounds like an engine again, instead of a semi-auto firecracker.

[Sentinel]

Hi,

I found this on some guy's website:


------------------------------
Valve Adjustment Video

Kerry Burton of GStwin.com has put together a very informative video chronicling the process of valve adjustment on his GS500. The procedure will be the same for all GS twins. The principle is the same for all 2-valve GS motors.

CLICK HERE to go to the Google video.
-------------------------------

That same website also has a Haynes and a Clymer manual for the GS450 and a carb rebuild guide.


Thank you for your indulgence,

BassCliff

Hi, I hope to be checking and adjusting the valves on my 1983 GS450E soon.

From what I've seen, it looks like I have a two-valve head, and it uses shims for adjustment, is that correct?

The link to the video is no longer working; do you have one that does?

Also if there's any information that you know of that may be specific or helpful regarding my specific bike, please let me know.

Last but not least, thanks for providing all the great information that you do for our bikes!

[Sentinel]

http://www.youtube.com/watch?v=K8E_zMLCRNg

[metalman]

Might be good to check your petcock. If there is gas coming from the vacuum line it's not good and will definitely contaminate your oil. Ask me how I know. I might not be reading your post correctly? Still check it anyway.