Topic: Cylinder "Cleansing" ????

[Popwood]

So I've been at my '75 750K for several weeks now with a goal to get her really running optimally and clear up rich running conditions (according to sooty plugs) on cylinders #1 and #4 particularly as #2 and #3 have been in the normal range. I've been through thorough carb clean, checked all that out twice; new points plate, points, condensers, the whole nine yards; valve adjust, cam chain adjust, timed and even got a dwell meter and set it just so. I feel I've really been through it all.

Question. If 1 and 4 have been running rich for some time and there's carbon build up on the piston head and cylinder walls, will it take some miles to burn up and give me good looking plug readings? The bike is running better than ever, really strong, but still some carbon fouling on 1 and 4? Plugs are NGK DE7s. After all the work, carbon on plugs was no improvement with DE8s. I'd really like to get this cleared up.

[OldSchool_IsCool]

I've never tried it, but I've read that misting the intake while idling with a few spays of water will "steam clean" the combustion chamber.  Might even try SeaFoam.

[Popwood]

I've never tried it, but I've read that misting the intake while idling with a few spays of water will "steam clean" the combustion chamber.  Might even try SeaFoam.

Thanks, Old School. Sea Foam is a thought. Anyone tried the "steam cleaning" route? As for Sea Foam, I think of it as a solvent based cleaner for things gunked up from petroleum products, like gas and oil. Would carbon fall into that category? Hmmmmmm......

[OldSchool_IsCool]

Another thought is Automatic Transmission Fluid.  It has cleansing properties too.

[Popwood]

Another thought is Automatic Transmission Fluid.  It has cleansing properties too.

And you mist into the intakes or drip into carb sync ports?  Anyone tried this?

[BobbyR]

I've never tried it, but I've read that misting the intake while idling with a few spays of water will "steam clean" the combustion chamber.  Might even try SeaFoam.

Thanks, Old School. Sea Foam is a thought. Anyone tried the "steam cleaning" route? As for Sea Foam, I think of it as a solvent based cleaner for things gunked up from petroleum products, like gas and oil. Would carbon fall into that category? Hmmmmmm......

I have done it, it is an old school trick and it works. The steam just blows out the carbon. It takes more than a mist, squirt it right into the carb in each cylinder one at a time. Let that each cylinder recover and hit it again. Takes a bit to really get it clean. Someone will mention hydrolock, it would take a glassful all at once to hydrolock a cylinder.

[BobbyR]

Another thought is Automatic Transmission Fluid.  It has cleansing properties too.

And you mist into the intakes or drip into carb sync ports?  Anyone tried this?

Synch port are fine. Squirt it in there. Best when the motor is hot and reving a bit.

[Popwood]

Thanks, booby, I mean Bobby-- where do you find those avatars!!!!!! And do you or Old School think this could clear up fouled plugs?  I mean assuming all else is OK?

[OldSchool_IsCool]

I don't think it will hurt.  Carbon buildup will, in effect, reduce the size of the combustion chamber thus increasing the compression ratio.  In extreme cases, this leads to pre-ignition and knocking. 

Try swapping the fouled plug with another cylinder that is burning clean.  If the carbon fowling follows the plug, then you may have an anemic plug.  Long shot but an easy check. 

Check also that your plug cap has the right impedance (ohms) and that there isn't any spark leaking off through the plug wire arcing to the engine block.  The arcing is easy to see at night or in a dark garage.

[BobbyR]

Thanks, booby, I mean Bobby-- where do you find those avatars!!!!!! And do you or Old School think this could clear up fouled plugs?  I mean assuming all else is OK?

Well it is not really about the plugs, it is as was mentioned about carbon buildup in the cylinders. Carbon can glow red hot and cause preignition and detionation. Carboned up plugs are a symtom of another problem.

The avatars are a byproduct of the Babe thread, I find a face I like and I crop them.

[Popwood]

Thanks, booby, I mean Bobby-- where do you find those avatars!!!!!! And do you or Old School think this could clear up fouled plugs?  I mean assuming all else is OK?

Well it is not really about the plugs, it is as was mentioned about carbon buildup in the cylinders. Carbon can glow red hot and cause preignition and detionation. Carboned up plugs are a symtom of another problem.

The avatars are a byproduct of the Babe thread, I find a face I like and I crop them.

Bobby, I realize carbon fouled plugs are a result of carb issues or ignition problems. Was just wondering if, after fixing the rich running condition the residual carbon in the cylinder could continue to make carbon deposits on the plugs? Or would fixing a rich condition immediately eliminate carbon on the plugs. After the work I've done, performance has never been stronger, yet in the first 25 miles I'm still getting too much carbon on the plugs. I'm also leaning the air screw 1/8 turn at a time looking for improvement from that. 

[srook]

The fouled plugs means you are running rich somewhere along the carb tract, but you need to find out where.  You need to do plug chops to find out which circuit in the carbs is causing the rich condition.  Are they loading up on idle, 1/4 throttle, 1/2 throttle, 3/4 throttle, or full throttle.  You are also going to need some new plugs.  Why did you switch to D7EA?  Your bike should be running on the D8EA.  This chart has been around awhile so you may be familliar with it:


Unless you correct the rich running condition their is no point to trying to "clean" your combustion chamber of carbon.  It will only build up again.  I would plug chop at 1/2 throttle (clip & main jet), 3/4 throttle (main jet), and full throttle (main jet).  If you are not getting any carbon on the plugs through plug chops then it is the idle circuit.
Good Luck
Scott

[Popwood]

Guess I'm overdue for a plug chop series. Went to D7s because they are hotter than D8. Am looking for more complete fuel burn. The D7s don't foul as much or even close to as quickly as what I had just tried, Denso plugs, I think the number is ES24SU. That plug was recommended by Hondaman as the better choice between a D8 and D7 NKG plugs.

Thanks srook.

[BobbyR]

Thanks, booby, I mean Bobby-- where do you find those avatars!!!!!! And do you or Old School think this could clear up fouled plugs?  I mean assuming all else is OK?

Well it is not really about the plugs, it is as was mentioned about carbon buildup in the cylinders. Carbon can glow red hot and cause preignition and detionation. Carboned up plugs are a symtom of another problem.

The avatars are a byproduct of the Babe thread, I find a face I like and I crop them.

No, any carbon dislodged from the heads would go out theough the exhaust valves, it does not vaporize and redeposit itself on other surfaces.
Bobby, I realize carbon fouled plugs are a result of carb issues or ignition problems. Was just wondering if, after fixing the rich running condition the residual carbon in the cylinder could continue to make carbon deposits on the plugs? Or would fixing a rich condition immediately eliminate carbon on the plugs. After the work I've done, performance has never been stronger, yet in the first 25 miles I'm still getting too much carbon on the plugs. I'm also leaning the air screw 1/8 turn at a time looking for improvement from that.