Gunk in bowls

So i had my bike at the mechanic's for a couple of minor things. When I picked it up he showed me a little glass of gas taken from one of the carb bowls. Bottom of the cup had some black crap in it. Smaller than sand, not sure how to accurately describe the size of a particle. Anywho, he said that this meant that I should certainly get the carbs cleaned out for which he wanted to charge me $100. (He's a somewhat kinda acquaintance so the price may seem low? or high, i have no idea) I told him I would think on it and rode home.
When I got home I pulled opened a bowl into a glass and saw more black crap.
He also put a new fuel filter in and I can already see black crap inside it.
I'm going to clean out my tank tomorrow, should I pay for the carbs?

It is something you can do yourself (If I can manage it...). Otherwise pay him to do it. If he says $100 for all four, take it and run.

Afrosemite wrote:

So i had my bike at the mechanic's for a couple of minor things. When I picked it up he showed me a little glass of gas taken from one of the carb bowls. Bottom of the cup had some black crap in it. Smaller than sand, not sure how to accurately describe the size of a particle. Anywho, he said that this meant that I should certainly get the carbs cleaned out for which he wanted to charge me $100.

You will find some of that in the bottom of ANY bowl. Even with clean gas, even with the best inline filters, the finest sediment gets through. Most of us drop the bowls once or twice a year and hose them out with carb cleaner spray.

You should learn to clean the fuel system. It will save you a lot of money over the life of the bike.

PFC FNG wrote:

It is something you can do yourself (If I can manage it...). Otherwise pay him to do it. If he says $100 for all four, take it and run.

I'll wager he has a home-made screwdriver tool to get the bowl screws off with the carbs in place... I do. I can R+R the bowls off my 750 twin in about 10 minutes.

He said he already cleaned out the bowls. The $100 was supposed to be to clean out everything else. I'm still on the fence about whether or not i need it at all. I wasn't too concerned to see a little junk in the bottom of the bowls but he made it seem like it was a big deal (as mechanics are want to do)

You should definitely tear down the carbs and do a complete clean, you don't have to separate the carbs from the rack,just get them off the bike and on to the bench. Follow the instructions in your manual and keep all parts separate for each carb. After you do it once you can do it with your eyes closed.

Everyone Knows carbs aren't easy, just lots of fun !

Afrosemite wrote:

He said he already cleaned out the bowls. The $100 was supposed to be to clean out everything else. I'm still on the fence about whether or not i need it at all. I wasn't too concerned to see a little junk in the bottom of the bowls but he made it seem like it was a big deal (as mechanics are want to do)

Couple of questions please which might result in better advice.

Are there any existing concerns about having a nice steady low rpm idle, and ability to smoothly and strongly pull away from idle without any hesitation or bogging?

Are the pilot adjustment screws located on the sides of the carbs or on the bottoms?

Afrosemite wrote:

...going to clean out my tank tomorrow....

Any doubts about the best method for flushing tank?

Lots of doubt on cleaning out the tank trying to figure out that one now. SOmeone told me I should use dawn soap and water. that seems like a bad idea. I may just rinse out out with some gas. I've also heard that phosphoric acid works nice and leaves a good film. Any suggestion there?

The only problem I'm noticing is that it bogs a bit pulling away quickly. Could be me though. In my mind this is mostly preventive stuff because in three months the bike is going to be sitting for a while and I want to get it all good and clean before that.
I am pretty convinced at this point that I am going to clean the carbs myself. I've been reading the clymer and I think i can handle it on myself. The only concern is the final vacuum syncing, is that going to need to be done?

IMO flushing out the tank is indeed a good first start toward assuring an ample clean fuel supply. Depending on how cruddy it is inside, sometimes a good flush will suffice without more drastic treatment (such as acid, or b-b's in the dryer, or electrolysis, or removing old liner material, etc.)

Perhaps better methods are out there, but here's how I do it ---

Drain tank (with line from petcock into a gas can sitting on the floor).
Remove empty tank from bike.
Put in say one quart of fresh gas and slosh it around.
Fast-dump gas out of fuel cap hole.
Repeat.
Remove petcock from tank.
Carefully clean all petcock filter screens.
Reinstall petcock onto tank.
Remove inline filter and clear it by blowing through it backwards using compressed air.
Install inline filter.
Replace tank onto bike.
Fill with fresh clean gas (not the old drained-out gas or the gas used for flushing).
Attach fuel line (and vacuum line, if so equipped) to petcock.
If using dual fuel lines into carb, will require two inline filters, one for each fuel line into carbs.

Good Luck!

...bogs a bit pulling away quickly. Could be me though...

Might be some blockage in the pilot circuit (air passages or fuel passages or in the pilot jet). One crude test is whether the pilot screw adjuster makes any difference in engine performance at idle rpm. Where no difference is noticable with different pilot screw adjuster settings, there's probably something wrong with the pilot circuit inside the carb (usually crud blockage).

...going to clean the carbs...only concern is the final vacuum syncing, is that going to need to be done?

Proper bench-synching during reassembly will get within range for later precise manometer synching on running engine. It also provides for approximate mid-location of the idle speed thumb-screw adjuster so it may be later moved either way (up or down) to regulate the idle speed rpm.

...In my mind this is mostly preventive stuff because in three months the bike is going to be sitting for a while and I want to get it all good and clean before that....

If current performance is acceptable, might consider postponing refurbishment of carbs, and run through a few tankfuls with Seafoam added, which could help clear the carb pilot circuits.

In any event, before longterm parking (or whenever parked overnight -- as is my routine procedure with manual petcock) should turn off petcock (prevents further fuel supply from tank) and allow the engine to run until the float bowls empty and the engine dies. This gets residuary fuel out of the floatbowls and fuel passages so its not left in there to stagnate). With a vacuum petcock, would at least drain all fuel from the floatbowls before parking the bike for any extended period of time.

Good Luck!

Forgot to mention --

For longterm storage, fuel tank should be either full or empty.

If full, should have proper amount of fuel stablizer added into the fuel (likely good for a year, maybe longer, but should remain viable at least throughout the non-riding season).

If empty, should coat interior with light oil sloshed around inside. For this purpose, WD40 would be better than nothing, as the tank is relatively air-tight which retards evaporation. Undoubtedly others here will offer some better ideas about this.

Good Luck!