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Main Area => General GS500 Discussion => Topic started by: SonsaFrantic on January 18, 2010, 01:37:50 PM

Title: Won't start after valve adjustment *UPDATED*
Post by: SonsaFrantic on January 18, 2010, 01:37:50 PM
I went down to my valves and replaced the shims, have good clearance, good battery, looks like I put it all back together well. Any ideas on what I might have missed?

----------------------
UPDATE

I can now get it to start it will only fire on the right two, but once I get the rpms around say 4500 both fire. I think I need to sync my carbs. -$$-
Title: Re: Won't start after valve adjustment
Post by: jeremy_nash on January 18, 2010, 01:50:03 PM
you pinched the fuel lines when putting tank back on, or you forgot to turn the tank mounted petcock back on.  dont ask me how I know.  ....................ok, Mr. Adrian Monk told me.
Title: Re: Won't start after valve adjustment
Post by: SonsaFrantic on January 18, 2010, 07:28:50 PM
Ok I tried that and now when I try to start it, it now sputters then turns over and starts to make a puffing sound (like as if on one cylinder).

:technical:

Good call btw on the gas tank shut off.
Title: Re: Won't start after valve adjustment
Post by: gregvhen on January 18, 2010, 07:42:20 PM
you adjusted wrong maybe. double check.  make sure you didnt confuse the intake with the exhaust.
Title: Re: Won't start after valve adjustment
Post by: SonsaFrantic on January 18, 2010, 07:44:26 PM
Got what confused?
Title: Re: Won't start after valve adjustment
Post by: BaltimoreGS on January 18, 2010, 07:55:19 PM
Is it running on one cylinder?  It is possible you could have knocked some crap loose in your fuel lines which clogged a carb.  Ask ver4 about that   :laugh:  Did you open the float bowl drains on both carbs to make sure they are getting fuel?

-Jessie
Title: Re: Won't start after valve adjustment
Post by: gregvhen on January 18, 2010, 08:11:52 PM
Quote from: SonsaFrantic on January 18, 2010, 07:44:26 PM
Got what confused?

dont the exhaust clearences differ from the intake? maybe he switched em so the valves are opening at the wrong times and causeing low compression
Title: Re: Won't start after valve adjustment
Post by: BaltimoreGS on January 18, 2010, 08:23:22 PM
The clearance spec. is the same for the intake and exhaust valves. 

-Jessie
Title: Re: Won't start after valve adjustment
Post by: SonsaFrantic on January 18, 2010, 08:30:15 PM
Whew had me scared. I have good clearance. I still figure carbs.
Title: Re: Won't start after valve adjustment
Post by: trumpetguy on January 18, 2010, 08:34:51 PM
Did you put the petcock on Prime for a few seconds, then back to ON?  Did you choke it?
Title: Re: Won't start after valve adjustment
Post by: SonsaFrantic on January 18, 2010, 08:38:28 PM
Yezzir. Did both I did prime to refill. It's getting gas. Just won't catch.
Title: Re: Won't start after valve adjustment
Post by: black and silver twin on January 18, 2010, 10:17:26 PM
Quote from: SonsaFrantic on January 18, 2010, 08:38:28 PM
Yezzir. Did both I did prime to refill. It's getting gas. Just won't catch.

did you make sure to hook both plug wires back on?
dont ask....
Title: Re: Won't start after valve adjustment
Post by: gregvhen on January 18, 2010, 10:44:49 PM
are your plugs good? have you checked for spark? how old are the pugs, and how much have you tried to start the bike without it firing. sometimes plugs can get compressed with fuel which grounds them out, but they will still fire outside the cylinder just not inside under compression.  Also you didnt mess with the timing at all did you? shouldnt have had to mess that up when setting valve clearence
Title: Re: Won't start after valve adjustment
Post by: SonsaFrantic on January 18, 2010, 11:36:16 PM
Lol yeah I have the plugs caps on. I didn't mess with the timing. Not 100% sure about the plugs. I'll buy some new ones if all else fails. It's looking like more and more like the carbs =/
Title: Re: Won't start after valve adjustment
Post by: Gary856 on January 19, 2010, 12:36:43 AM
This is why I'm afraid to tackle a job like valve inspection/adjustment that the more (much more) mechanical gifted guys here consider "not difficult". I found out even a simple oil and filter change can turn into a multi-day headache the first time I did it. So for valve adjustment I let the shop do it at $100/hour + parts to save me my sanity.  :laugh:
Title: Re: Won't start after valve adjustment *UPDATED*
Post by: SonsaFrantic on January 19, 2010, 09:48:17 PM
I can now get it to start but only halfheartedly, and anything before 4500 rpms the right side is the only side firing... HELP!
Title: Re: Won't start after valve adjustment *UPDATED*
Post by: jeremy_nash on January 20, 2010, 05:41:39 AM
pilot jet on the left carb is clogged, time to take them apart and clean them too
Title: Re: Won't start after valve adjustment
Post by: ver4 on January 20, 2010, 10:11:37 AM
Quote from: BaltimoreGS on January 18, 2010, 07:55:19 PM
Is it running on one cylinder?  It is possible you could have knocked some crap loose in your fuel lines which clogged a carb.  Ask ver4 about that   :laugh:  Did you open the float bowl drains on both carbs to make sure they are getting fuel?

-Jessie

Haha, funny guy.  :flipoff:  ;)

Sonsa, what Jessie was referring to was this past Saturday when I wanted to take my bike out for a ride the carbs were clogged.  It just made my day worse.  Also, I have no mechanical skills whatsoever.
Title: Re: Won't start after valve adjustment *UPDATED*
Post by: SonsaFrantic on January 20, 2010, 12:22:32 PM
Lol. Ok well imma clean my carbs and all. I'll post pictures and stuff.
Title: Re: Won't start after valve adjustment *UPDATED*
Post by: noiseguy on January 20, 2010, 01:22:10 PM
Check for a loose carb boot (carb to engine and carb to airbox) as well as loose vacuum lines. These can get bumped loose during this job.

Based on symptoms dirt in the pilot is most  likely. But it seems odd that the carb would gum up during the valve job. I take it that the bike was fine before you pulled the cover?
Title: Re: Won't start after valve adjustment *UPDATED*
Post by: SonsaFrantic on January 20, 2010, 02:10:52 PM
Well the bike has 48000 miles on it. My dad didn't do much work on it. So it wasn't running really well.
Title: Re: Won't start after valve adjustment *UPDATED*
Post by: The Buddha on January 20, 2010, 02:22:04 PM
Running on the right only till 4500 rpm = loose or disconnected vacuum line or missing O ring under the top cap.
Cleaning - not required, its running implies the slow circuits are OK ...
Cool.
Buddha.
Title: Re: Won't start after valve adjustment *UPDATED*
Post by: noiseguy on January 21, 2010, 09:05:03 PM
Quote from: The Buddha on January 20, 2010, 02:22:04 PM
Running on the right only till 4500 rpm = loose or disconnected vacuum line or missing O ring under the top cap.
Cleaning - not required, its running implies the slow circuits are OK ...
Cool.
Buddha.

Isn't the slow circuit pretty much out of the picture above 4500 RPM? I've had bikes with blocked idle circuits that run great at WOT, but won't idle. Carb clean fixes these. Is that not the case on these Mikunis?

I was thinking it's more likely that he knocked a vacuum line loose in the valve service just b/c if the carbs were fine before, they should be fine now.