Preparing for carb rebuild

[Toner]

Hi guys, going to be doing a carb clean and rebuild so I'm researching what I need. It's my first time trying it. I'm going to be following along to a few video tutorials and one blog.

I was wondering, should I really get bigger jets like the blog says:

"Replace the pilot jet with a new pilot jet, and go up one size from stock. This is a #40 for the '89-00 bikes and a #20 for the '01+. Don't bother trying to clean or reuse the old ones. They are easily clogged and cheap to replace."

https://joshkarnes.blogspot.ie/2017/09/fixing-common-gs500-carburetor-issues.html

I have an 00 GS500e

And do you know if this the rebuild kit I'll need: 
https://www.ebay.co.uk/itm/1989-00-Suzuki-Carburetor-Carb-Repair-Rebuild-2-kits-gs500-gs500e-needle-oring/352222812752?hash=item52021d9a50:g:wi0AAOSwu4hazt-i



Is there any store you would recommend get a different one?
Does that kit include the jets or do I need to buy them separately? Where should I buy them?

Was also wondering whether I should get one of these carb sync tools and sync the carbs with it as part of the job?
I never see it mentioned in the tutorials but there are seperate videos on doing that job.



Guess I need some JIS screwdrivers but not sure what size I need. Sizing on them seems strange.
One video on doing the carbs on a cb500 suggested getting a P2x150 and a p3x150.
Any advice on that for the GS?

[user11235813]

Get an impact driver, or just wrench the screws off with grips then throw them away and replace with allen head bolts. Use the bolts with a deep set hex hole and little grooves on the side like coins, easier to handle than the dome head bolts with a smaller hex hole.

Go with a home made man-o-metre plenty of vids on you tube. just two bottles and some clear tubing.

[Toner]

I don't know. Looks like by the time I bought all the stuff to build this and then build it, it would have been easier to just buy the tool. 

https://www.youtube.com/watch?v=2jVl-0PdrRk

[user11235813]

It's pretty easy, use two water bottles with screw caps. Filled halfway with coloured water. make two holes in each cap U shaped tube connects the two bottles and reaches down to the bottom. The other hole in each lid has one tube that goes to each vacuum port on the carburettor and only extends a little way past the cap. Seal the tops with epoxy resin or even blu tac will probably do the job.

[The Buddha]

You don't need either to synch the carbs. Look to a bright spot and adjust the idle screw to set the crescent of light as thin as possible, and then adjust the butterflies to be equal. That's a lot easier if you have the carbs off, which you would when installing a rebuild kit.

BTW you sure you need a rebuild kit ? is the float gasket leaking ? Else you're better off buying O rings or the float needle if its bad.

Cool.
Buddha.

[mr72]

You probably don't need the float bowl gasket. The set is overpriced for what you will get. Worthwhile instead to get new intake boot o-rings and replace those while the carbs are off.

Look here for o-rings on the cheap: http://www.thisoldtractor.com/for_sale_dr350_orings.html

BTW that's my blog. Glad it is helping some folks. I am pretty sure I recommend replacing the intake boot o-rings on the blog post

[Toner]

You probably don't need the float bowl gasket. The set is overpriced for what you will get. Worthwhile instead to get new intake boot o-rings and replace those while the carbs are off.

Look here for o-rings on the cheap: http://www.thisoldtractor.com/for_sale_dr350_orings.html

BTW that's my blog. Glad it is helping some folks. I am pretty sure I recommend replacing the intake boot o-rings on the blog post

Thanks for the help and blog post.

Those kits seemed overpriced alright. Maybe I can get it cheaper somewhere else. I may need the float bowl gaskets so I'd prefer to have them in case I do need them and then I might as well change them anyway. That link you provided is for a DR350? Are they the same o-rings used in the GS500?

Do you know where I could buy jets and do I really need to get the bigger size or why are you recommending that?

[mr72]

The DR 350 has the same carb as the GS500 carbs. Just half as many. The jets are different and maybe needles but the o-rings are the same.

I would replace the float needle valves (not necessarily the "seat" .. brass part) as a just-in-case, but in neither set of my ancient and abused carbs did the float bowl gaskets leak so I don't see the need.

You will need to jet up at least the pilot jet, depending on year, to either a 20 or a 40. It won't hurt to bump the main jet up a size as well. The Mk1 carbs ('89-00) work great with 40/125 jetting, which is one size larger than stock on both. Plus the pilot jet is hard to clean and easy to replace, and cheap.

You can get jets anywhere, even some on this forum sell them. eBay, amazon, Bikebandit, etc. Try to get "genuine" Mikuni branded jets, mostly because the size and profile is a known quantity.

Including jets and intake boot o-rings you should be able to get everything for both carbs for under $40, under $30 if you are a careful shopper. But if someone packages a kit for $50 then I think it'd be worth it to not have to hunt it all down. However no kits include the intake boot o-rings and they are a dealer only part probably cost $4/each.

All in all it's still cheap and best to do it all at once.

[alpo]

A set of JIS screwdrivers will save you a lot of headache. I got screwdriver bits from here. The shipping was more than the bits, but the bits fit the screws perfectly.

If you have an ultrasonic cleaner handy the jets are easy to clean. Otherwise, as suggested above, they are inexpensive to replace.

Check to see if your throttle shaft seals have been weeping. You can tell by discoloration/residue built up around them. If you need new seals I found Suzuki 13651-51010 fit properly on my '02.  They should fit your '00.  If you need to replace them removing the carb butterflies takes a little patience: you need to file down the peened end of the screws. The JIS screwdrivers really make a difference here. Plan on installing new butterfly screws with some red Loctite. Suzuki butterfly screws are 13604-44080, but can be found aftermarket for less.

The Motion Pro sync tool is great, but an additional expense. I bench sync'd my GS500 carbs by measuring the butterfly height with digital calipers. Measure one then use the sync screw to adjust the other. She purrs with just the bench sync.

[Darkstar]

buy jets and allen head bolts from The Buddha, then get o-rings from thisoldtractor,

and drill out the brass plug covering the pilot mixture screw, as it allows you to dial that circuit in nicely, plus you'll look cool doing it when you stop for coffee on the group rides   

[Toner]

A set of JIS screwdrivers will save you a lot of headache. I got screwdriver bits from here. The shipping was more than the bits, but the bits fit the screws perfectly.

If you have an ultrasonic cleaner handy the jets are easy to clean. Otherwise, as suggested above, they are inexpensive to replace.

Check to see if your throttle shaft seals have been weeping. You can tell by discoloration/residue built up around them. If you need new seals I found Suzuki 13651-51010 fit properly on my '02.  They should fit your '00.  If you need to replace them removing the carb butterflies takes a little patience: you need to file down the peened end of the screws. The JIS screwdrivers really make a difference here. Plan on installing new butterfly screws with some red Loctite. Suzuki butterfly screws are 13604-44080, but can be found aftermarket for less.

The Motion Pro sync tool is great, but an additional expense. I bench sync'd my GS500 carbs by measuring the butterfly height with digital calipers. Measure one then use the sync screw to adjust the other. She purrs with just the bench sync.

measure the butterfly height with digital calipers?
I've seen people sticking needles in to gauge the gap but cannot picture being able to use calipers.
I've been looking at more videos of homemade carb sync tools.   
If I get two meters of 5mm tubing like this, do you know what If I need anything to get the tubing attached to the carbs or will it just slide on nice and tight?

Thank-you very much for supplying the part numbers. 

[Toner]

buy jets and allen head bolts from The Buddha, then get o-rings from thisoldtractor,

and drill out the brass plug covering the pilot mixture screw, as it allows you to dial that circuit in nicely, plus you'll look cool doing it when you stop for coffee on the group rides   

Do they have a store or do I just PM them? 

Is this the brass plug you are talking about?

[mr72]

That's not a plug, or at least not one you want to drill out. The plug he's talking about is on the BOTTOM of the carb, covers the pilot adjuster.

Hit the FAQs, watch some videos on adjusting the carbs, go read my blog post on it, it's easy to get your head around.

[alpo]

measure the butterfly height with digital calipers?
I've seen people sticking needles in to gauge the gap but cannot picture being able to use calipers.

It works. Inexpensive digital calipers from Harbor Freight measure in the 100's, which is plenty accurate for this. With the carbs on your bench measure the distance from the top of one butterfly to the mouth of the carb. Adjust the sync screw until the same place on the other butterfly is the same distance.

Thank-you very much for supplying the part numbers.

You're welcome. 

[The Buddha]

buy jets and allen head bolts from The Buddha, then get o-rings from thisoldtractor,

and drill out the brass plug covering the pilot mixture screw, as it allows you to dial that circuit in nicely, plus you'll look cool doing it when you stop for coffee on the group rides   

I also have the O rings. If I can find em now - well that's the question.
Cool.
Buddha.

[Toner]

buy jets and allen head bolts from The Buddha, then get o-rings from thisoldtractor,

and drill out the brass plug covering the pilot mixture screw, as it allows you to dial that circuit in nicely, plus you'll look cool doing it when you stop for coffee on the group rides   

I also have the O rings. If I can find em now - well that's the question.
Cool.
Buddha.

If I can get it all from you, that would be great. Do you have the one-sized-up jets Alpo is talking about? 
If you have the boots too, even better.
Let me know, Cheers Buddha.

[Toner]

You don't need either to synch the carbs. Look to a bright spot and adjust the idle screw to set the crescent of light as thin as possible, and then adjust the butterflies to be equal. That's a lot easier if you have the carbs off, which you would when installing a rebuild kit.

BTW you sure you need a rebuild kit ? is the float gasket leaking ? Else you're better off buying O rings or the float needle if its bad.

Cool.
Buddha.

I don't know what I need. I figured I'd just replace everything while it's off. The carb has probably never been off and cleaned in its 80,000 Km. I got the bike second-hand some years back. 
I'll bench sync them as good as possible but I'm reading even then they may not be truly synced so I figured I'd do a carb sync while I am at it. Good to learn anyway. 
The homemade carb syncer looks do-able.
Still just wondering if I buy some 5mm tubing like this, do I need anything else to attach the tubes to the vacuum ports?

[user11235813]

@Still just wondering if I buy some 5mm tubing like this, do I need anything else to attach the tubes to the vacuum ports?

Well the vacuum ports do use a smaller diameter tube so you'll need to something to step it down.

[Toner]

@Still just wondering if I buy some 5mm tubing like this, do I need anything else to attach the tubes to the vacuum ports?

Well the vacuum ports do use a smaller diameter tube so you'll need to something to step it down.

so how about I just get 12 foot of 3mm tubing like this site says? 
http://www.650ccnd.com/mano.htm

[user11235813]

so how about I just get 12 foot of 3mm tubing like this site says? 

Even better!

I'd still prefer bottles rather than the setup you linked to.

This is the best and clearest video https://youtu.be/AvmVNrQpOao