need help: 04GS500f missing intake manifold gaskets etc.

[lawman]

So, in this disaster 04 GS500f I'm working on, when I took the carbs off I found out that the intake manifold to the engine was missing a screw.  Then I took if off and found out it had no gasket.  First, could this have prevented the bike from starting (vacuum leak)?  Second, where do I get these gaskets?

I'm putting #20 pilot jets in.  This should make starting easier right?

Regarding the carbs: Will gumout carb cleaner eat my plastic parts?  Will sea foam in a spray can?  What should I use?  Do I HAVE to clean the choke (- requires separating the carbs)?

As I look at this bike more and more, I notice things:

the front tire is worn in a ... scalloped pattern - it has bumps in it.  Any ideas why?

the fender on the front wheel is... melted on the right side.  Could the engine have gotten hot enough to do that?

the gasket at the top of the cylinders (valve cover) has oil that leaked all around it.  What could have caused this?

I'm starting to think this engine may have overheated.  I had it started with squirts of carb cleaner, so I know it CAN be started.  If I'm right, what sorts of things to I need to prepare for?

Sorry to be a pain.  Thanks.

[ohgood]

So, in this disaster 04 GS500f I'm working on, when I took the carbs off I found out that the intake manifold to the engine was missing a screw.  1) Then I took if off and found out it had no gasket.  First, could this have prevented the bike from starting (vacuum leak)?  Second, where do I get these gaskets?

2) I'm putting #20 pilot jets in.  This should make starting easier right?

3) Regarding the carbs: Will gumout carb cleaner eat my plastic parts? 
4) Will sea foam in a spray can? 
5) What should I use? 
6) Do I HAVE to clean the choke (- requires separating the carbs)?

As I look at this bike more and more, I notice things:

7) the front tire is worn in a ... scalloped pattern - it has bumps in it.  Any ideas why?

the fender on the front wheel is... melted on the right side.  Could the engine have gotten hot enough to do that?

the gasket at the top of the cylinders (valve cover) has oil that leaked all around it. 
9) What could have caused this?

I'm starting to think this engine may have overheated.  I had it started with squirts of carb cleaner, so I know it CAN be started. 
10) If I'm right, what sorts of things to I need to prepare for?

11) Sorry to be a pain.  Thanks.

1) there is no gasket there, just the rubber from the intake pipes. or at least i haven't seen one on mine, nor on the parts fiches on bikebandit.com <---- they have excellent fiches you can search through prior to purchases !

2) hmm, there is a rejetting 'matrix' on the forum, a quick search for your type of carbs will show what is recommended. your gs has a 3 circuit carb as opposed to the older 2 circuit carbs. sorry, can't help ya there, but the wiki and matrix can.

3) don't trust the rubber OR plastic parts to any carb cleaner. dissassemble completely, clean clean clean, reassemble, enjoy. new o-rings can be had from ACE hardware, Lowes (sometimes), and the-buddha has kits (and does repairs on the CHEAP) for our carbs.

4) see #3, trust nothing, and you'll get to keep your precious carb pieces !
on a side note i've used seafoam on the bike/truck and all the carb bits were fine. we're talking about the junk you suck through a vacuum line though, nothing else.

5) carb cleaner, but NOT on any of the plastic or rubber pieces ! your float needle also has a rubber tip that is very sharp, solvents may degrade it, causing the need for a new one.

6) nah, i never have. i actually don't need the choke anymore my bike is so rich on the low end (2 circuit carb, rich on the idler, perfect on the main jets)

7) a newbie rider. braking late in a turn, or too heavily while leaning causes this from what i've read. don't blame the rider though, cause all my BT45's do this, and I"M A PERFECT RIDER THAT NEVER EVER MAKES MISTAKES and mine do this too

yep, sure will. some bikes are idled for too long, and it will melt the fender. most likely the bike was too lean (makes it hotter) and idled. might have even been really bone headed and had the headers off to be 'cool' or something.

9) see 8
10)  well, if the engine spins freely (on center stand, in neutral, you spinning the rear wheel) and doesn't make bad noises, you should be fine. generally the gs is a very tough engine, and it has a wide range of normal noises from what is almost piston slap, to cam noises, to valves bangin around (DONT FLOAT THE VALVES BY OVER REVVING !) to all kinds of neat internal noises.

by spins freely, i mean you will want to pull the spark plugs, and see how freely it spins. with the plugs out you can FEEL the valve train's resistance as you try to spin the rear wheel, and the pistons reversing direction. now imagine all those internals doing the same things at 10,000 revolutions per minute- that's  166 revolutions PER SECOND, and think about how freaking fast those poor pistons are changing direction. ouch, give her a brake up towards the top of the rpm range. she doesn't make any more power past 9,500 rpm or so, and valve float is only a 1000 or 2000 rpms away after that. valve float is normal, but if it goes too long or too high an rpm, the intake and exhaust valves will touch things, and that's just bad man. like 'crossing the streams' bad. (ghostbusters era)

11) no way dude, we all get to learn and explore stuff about this fun little bike together. enjoy !

[lawman]

Thanks for the info.

I thought it was funny there was nothing there when I took the manifold off, and the parts fiche shows an O ring in the intake manifold.  Is this the metal ring up against the head?  Without a gasket, I'm not entirely sure how you get a vacuum seal.  Anyone have any thoughts?

You mean all the tiny rubber o-rings in the carb can be found at ace and Lowe's?  THAT'S good info...

[coll0412]

There is supposed to be an oring on the backside of the rubber intake boots. Its Part #21 on the parts fiche below and Mr. Cycles has it for $2.40 each. The metal on the back of the boot has the o-ring groove cut into it.