Need carb advice

[Anonymous]

This one's on the 1982 1100EZ.

I checked my spark plugs today. The right two, #3 and #4 were like this:

The left pair, #1 and #2 were somewhere between these:

Other background info:
My air filter is a rather questionable aftermarket part and kinda dirty. I hear the pops of small backfire on deceleration. At full throttle (at least in neutral) the exhaust churns out visibly black smoke.

The bike was last run at highway speed and then in town for a total of 25-30 minutes.

Question #1 is this: What should I do to tune up my fuel system? I want to minimize downtime and expense. I figure that I could easily clean the air filter to lean out the rich cylinders, but wouldn't that also equally lean out the good ones? I'd like to delay completely stripping the carbs down. I have no time for such things and no money to pay somebody else to do it.

OK. just one main question.

Thanks!

Michael

 

[earlfor]

Re: Need carb advice

Michael, I'm just gonna give it to you straight. Engines dont give a hoot if you have time or not. Either you fix them or they dont work. There isnt anything inbetweem. cleaning your air filter will do nothing for your problem. Your carbs are so far out of synch and in the wrong vacuum range, it isnt funny. At least check your ignition timing, clean your airfilter, buy new plugs and synch the carbs. Either you fix it or you dont fix it. Half fixed is still all broke.

Earl

Question #1 is this: What should I do to tune up my fuel system? I want to minimize downtime and expense. I figure that I could easily clean the air filter to lean out the rich cylinders, but wouldn't that also equally lean out the good ones? I'd like to delay completely stripping the carbs down. I have no time for such things and no money to pay somebody else to do it.

OK. just one main question.

Thanks!

Michael

 

[Anonymous]

Re: Need carb advice

Michael, I'm just gonna give it to you straight. Engines dont give a hoot if you have time or not. Either you fix them or they dont work. There isnt anything inbetweem. cleaning your air filter will do nothing for your problem. Your carbs are so far out of synch and in the wrong vacuum range, it isnt funny. At least check your ignition timing, clean your airfilter, buy new plugs and synch the carbs. Either you fix it or you dont fix it. Half fixed is still all broke.

Earl

Thanks! Tellin it straight is A-OK for me. Let me ask you this, though: These plugs are only 500 miles old. Do they really need to be replaced?

I'm familiar with the sync thinger, but what's this talk about the vacuum range? Will a standard sync procedure fix it or are you talking about a different problem?

Mechanically, what is going on? Are my two better cylinders, 3 & 4, working right in the intended throttle range while 1 & 2 are below idle and having far too much fuel while no air comes in on the vacuum?

Ignition timing? You mean the things under the breaker cover, right? I can check Clymer for the details, but am I in the right neighborhood?

I think I might have a buyer for my car so I might soon have some cash to work with. You are right though: "Engines dont give a hoot if you have time or not."

Michael

 

[earlfor]

Re: Need carb advice

Just going to intersperse my replies after your questions. Easier that way.

These plugs are only 500 miles old. Do they really need to be replaced?
************Fouled plugs do not fire properly and consequently, it is impossible to accurately tune and synch using dirty plugs. If you only have 500 miles on them, I would take'em out, soak them in a cup of vinegar overnight to remove the carbon and crud and reuse them.


I'm familiar with the sync thinger, but what's this talk about the vacuum range? Will a standard sync procedure fix it or are you talking about a different problem?
************"synch thinger"? hmmmm, Are we referring to a mercury carb stix? heh heh You need one to do an accurate synch.
Some do a mechanical (measured synch) and some people do a vacuum
(carb stix) synch. A mechanical synch (on VM carbs) is nothing more than the required preliminary set up for doing a real synch (vacuum synch). The steps required are different for VM and CV carbs. I believe your bike has CV carbs, so the adjustment range is fairly narrow and easier to deal with.
Vacuum range........intake velocity relative to throttle position depends on the height the slides start to move from. As the slides raise, velocity decreases and less fuel is siphoned into the airstream. The engine will run rich or lean depending on what vacuum range the carbs operate in. Synching usually is interpreted that they all operate in the same range.....right or wrong. The carbs can be set uniformly wrong.
With stock jetting, pipes and airfilter, a vacuum level of 8-10 in Hg at 1200 rpm is about right.




Mechanically, what is going on? Are my two better cylinders, 3 & 4, working right in the intended throttle range while 1 & 2 are below idle and having far too much fuel while no air comes in on the vacuum?
********** it isnt the idle rpm/speed that is the problem, it is the intake velocity through the carb throats causing your plug mismatch.



Ignition timing? You mean the things under the breaker cover, right? I can check Clymer for the details, but am I in the right neighborhood?
******* Ignition timing is set by rotating the base plate located under the cover on the right end of the crank. Some models with electronic ignition are not adjustable. An easy way to tell if yours are adjustable is to remove the cover and look at the breaker plate. The braker plate is held in place by three screws at the 12, 4 and 8 oclock positions. If you have adjustable timing, the screw at the 12 oclock position will be in a slot in the breaker plate allowing plate rotation. Non adjustable ignitions only have a mounting hole.....no slot.....consequently no adjustment possible.


Earl

 

[Anonymous]

Most manometers I see for sale feature 5mm ports, while Clymer says I have 4mm ports. Is that correct?

Vacuum range: So you're saying that my CV slides are working incorrectly? Are you sure? Clymer doesn't say anything about that, so are they not adjustable? Would that suggest that some of my diaphragms are torn?

Clymer says that the 80-81 models have non-adjustable electronic timing. I have an 82 but I doubt they'd move backwards... still, I'll check.

 

[Billy Ricks]

On cleaning plugs, most people in the 45 and older group probably remember carbon-tetrachloride. When it was available most folks weren't very environment conscious. Carbon-tet was pretty unfriendly stuff so because it wasn't handled properly it got taken off the market. It still gets used commercially under tight control and if you knew what to look for you could get it under other names for awhile even after carbon-tet sales stopped.

It was replaced bya slightly altered molecule of itself. I'm not sure if the average Joe can by it, but book restorers use it. I know this because my FIL who recently passed away had some. I'm going to get it and treasure it.

For those that never used carbon-tet, you could take a set of sooty plugs like those pictured and soak them in the solvent. With a little light brushing the plugs would look almost new, ready to use again.

 

[Anonymous]

For those that never used carbon-tet, you could take a set of sooty plugs like those pictured and soak them in the solvent. With a little light brushing the plugs would look almost new, ready to use again.

Might carb cleaner do alright?

Michael

 

[Billy Ricks]

Might carb cleaner do alright?

Electric motor and parts cleaner would be better. For awhile you could get gun cleaner and dry cleaning solution that was still based on the carbon-tet molecule. It would dissolve anything carbon based. Nasty plugs would be almost white again. Nothing else comes close to working the way it did.

 

[earlfor]

Most manometers I see for sale feature 5mm ports, while Clymer says I have 4mm ports. Is that correct?
************
Both of my GS's have 4mm. To the best of my knowledge, all
GS models use 4mm vacuum fittings.



Vacuum range: So you're saying that my CV slides are working incorrectly? Are you sure? Clymer doesn't say anything about that, so are they not adjustable? Would that suggest that some of my diaphragms are torn?
**********
There could be a hole or cracks in some of the diaphrams, or
It could be that your throttle plates are out of adjustment. The manual for your bike should give setup instructions for the throttle plates.



Clymer says that the 80-81 models have non-adjustable electronic timing. I have an 82 but I doubt they'd move backwards... still, I'll check.

***********
Just look at the hold down screw at the 12 oclock position. If it is not mounted in a slot, then your timing is not adjustable.

Earl