Carb adjustments

[kurifu]

I called a local shop, Procycle, to see if they could adjust the fuel mixture and sync my carbs, and they warned me that since I have an old bike that they could end up making things worse.

I assumed that there were going to do a colortune, but it ends up that they don't do that, I was told that the will simply set the carb settings back to the manufacturers defaults and guess from there to "tune" it.

Is it just me, or does guessing here seem like a really bad idea? They want about $150 CDN to do this, and I don't think I am confortable with someone guessing at my settings, jees even I could do this with about 30 minutes of work.

I think I am going to make the purchase of a colortune and carbtune kit and handle the adjustments myself.

Is that how shops really are supposed to do this though? Guessing at the fuel mixture settings.

[kurifu]

If I buy my own colortune kit, do I have to have the shop vacuum sync first, or so I tune it than have them sync the carbs? Also any resources where I might find a good read on how to best make these adjustments and do the colortune.

[rapidray]

If you haven't done so lately, check the valves & adjust if required. THEN sync the carbs because valve adjustments change the carb sync. Also, stay away from a shop that is so "NEW" that they don't know how to do CARB work. Find a mechanic that KNOWS carbs! I wish you were in SoCal, I would help you out & have you happy inside of a couple of hours. All of the things you listed that you want to do you could buy the tools for for a couple hundred bucks & have them the rest of your life! Ray.

[kurifu]

I see... well good thing I was getting prepared to do my valve clearance this weekend and order the new shims. I did a gasket job about two weeks ago and didn't put the cam cover gasket on properly, so oil leaks like crazy out of it, now I intend on putting a new one on, but I am also getting a slight tapping sound from the number 4 cylinder, I figure this is the valve clearance as I accidentaly confused some of the shims when putting everything back together and made the mistake of net checking the clearance the first time (completely forgot, don't ask how).

[denydog]

If your bike is stock, including the air box, then carb tuning is not very complicated, even without fancy tools. Reading the plugs, and using a cheap sync guage should do a pretty good job, assuming the carbs are clean inside. You could probably get basic settings here if we know what bike you have.

[mark]

I think I am going to make the purchase of a colortune and carbtune kit and handle the adjustments myself.

There you go. Actually I'm impressed that the shop you went to was that candid and honest with you.

[Nightmare]

If your bike is stock i don't know if you need to bother adjusting the mixture screws, every repair manual I have read has stated in big bold letters to leave them the hell alone...

Personally, I would check the valves,, clean the carbs (espically if you suspect they are dirty), replace the o-rings and bowl gaskets (just clean the jets, don't worry about needle wear unless you have a lot of miles on the bike)...

Then sync the carbs (funny readings? check for air leaks on the intakes, if you feel like cursing for a lil while at the annoying phillips screws on the intake boots, replace the O-Rings (cheap) but unless the boots are really bad or damaged leave them alone (expensive) ). Now, run your colourtune through the cylinders, if it still looks way too rich/lean then adjust the mixture (aka air screws), be warned, Suzuki used thread lock on the screws so MAKE SURE YOU USE A GOOD FITTING SCREWDRIVER! (or be prepared to search on the forum "how to remove a damaged air screw").

[mark]

If your bike is stock i don't know if you need to bother adjusting the mixture screws, every repair manual I have read has stated in big bold letters to leave them the hell alone...

Yeah, maybe for the first decade of ownership. But of course by the time we get these bikes they've usually been messed with enough that you need to know how do do your own adjustments.

[49er]

Yeah, maybe for the first decade of ownership. But of course by the time we get these bikes they've usually been messed with enough that you need to know how do do your own adjustments.

Good advice. You also need to remove them to sucessfully clean out any partially blocked passages with compressed air. This is essential to ensure complete carb cleaning.

[kurifu]

If your bike is stock, including the air box, then carb tuning is not very complicated, even without fancy tools. Reading the plugs, and using a cheap sync guage should do a pretty good job, assuming the carbs are clean inside. You could probably get basic settings here if we know what bike you have.

Agreed, but what I was told over the phone, which makes a lot of sense, was that after 23 years sometimes the properties of the carbs tend to change a little bit, fuel can even etch away at the carburators changing the inner size of the bore, not by much, but likely enough with time to make a difference.

Now don't get me wrong, this shop is one of the best in this area as it ends up, probably the only place you can locally get a lot of various parts as well, I expect this is why they chose to be honest; to make up for the lack of equipment to do the test the proper way (in my opinion).

My bike is a 1980 GS1000GT, revs a bit high right now at about 2.5k up as much as 3k when the engine is warm. I have already checked the plugs and I think the engine is running a little bit hot, not enough to make me concerned though I would like to adjust it.

I have two other friends who live nearby who have bikes within 3 years of mine and want to do the same thing, so I think the lot of us are just going to purchase the gear.

I appreciate everyones insight.

[kurifu]

OH yeah, so if you live in Nova Scotia and need a colortune, give me a shout

[Jagir]

OH yeah, so if you live in Nova Scotia and need a colortune, give me a shout

I'm thinking you could set up a little fish & chip and colourtune shop on one of the pullouts on the Cabot trail.

[Steve]

My bike is a 1980 GS1000GT, revs a bit high right now at about 2.5k up as much as 3k when the engine is warm. I have already checked the plugs and I think the engine is running a little bit hot, not enough to make me concerned though I would like to adjust it.

What you are describing here is a classic case of bad o-rings in the intake tubes. They are only about $2 each (maybe CDN$3). Be careful with the intake tubes when you remove them to get to the o-rings. If they are hard or brittle, they will need to be replaced and they are about $20 each. Might be best to do them anyway, as they tend to need replacing every 25 years or so. 8-[


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