Thoughts On This Welcomed Dreaded Carbon

funky

funky

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Hi all Just wondering about how to minimise carbon build up in the engine. Not intrested in increasing power but just minimising carbon build up.
SOOOOO polishing Piston tops would reduce carbon build yes or no Remember this is not about increasing horse power .
I noticed that high end components are polished and a little reasherch seems to point to reduced carbon build up and hot spots to eliminate pre ignition, not sure if this more for cars than bikes with regard to pre ignition.
Any way What do you think
All the best and thanks for BoB Kelly III for the insperation
 
Polishing piston tops is not how to reduce carbon build up.
Correct engine assembly, correct air/fuel mixture, and correct timing are all that's required. Same as all 4 cycle engines.
 
+1! Funky, don't fix what ain't broke; the big carbon buildup you're seeing was caused by oil getting into the combustion chamber where it didn't belong. If you want to polish the exhaust ports, fine; just don't remove a lot of material, those ports are more than big enough already, and making them bigger will reduce flow, not otherwise. You can knock off the casting flash in the intake ports with coarse paper rolls, but don't polish them; bit of roughness keeps fuel atomized. Again, if I were you I'd avoid removing material; mistakes are easy to make, and IMHO port mods are best left to experienced techs with access to a flow bench.

Congrats on your patience, attitude, and decision to do your own assembly work!
 
grizld1 said:
- - - If you want to polish the exhaust ports, fine; just don't remove a lot of material, those ports are more than big enough already, and making them bigger will reduce flow, not otherwise. - - -
Click to expand...

Hi Grizld1,
I have a fuzzy memory of seeing photos of a flowbench wizard working his magic on an XS650 head.
His claim was the XS650 head ports were already too big.
His first step was to build 'em up inside with TIG weld before starting to re-shape them.
 
I've done this, and this is what I've noticed. For a couple of years now I've been using TC-W3 in the gas of my two Honda CB750 Customs, about 2 ounces to a full tank, maybe three tanks in a row every month. Even after a few tanks of straight gas I've noticed an increase in compression and a change in valve clearance after I started doing this. OK, the change in valve clearance was as if some carbon had been removed from the valve seats, about .0015" on most exhaust valves, intake valves pretty much stayed as they were. This TC-W3 is not the same two-stroke oil from the old days. If my valves are more carbon free than before, the piston tops may be also.

Scott
 
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Right, Fred; you may have been reading Jack's threads. He ported my head, so I can tell you from experience that the man knows his business.
 
funky said:
Hi all Just wondering about how to minimise carbon build up in the engine. Not intrested in increasing power but just minimising carbon build up.
SOOOOO polishing Piston tops would reduce carbon build yes or no Remember this is not about increasing horse power .
I noticed that high end components are polished and a little reasherch seems to point to reduced carbon build up and hot spots to eliminate pre ignition, not sure if this more for cars than bikes with regard to pre ignition.
Any way What do you think
All the best and thanks for BoB Kelly III for the insperation
Click to expand...
Certainly, polisher piston tops may help eliminate carbon buildup as well as hot spots that could lead to pre-ignition. Although this technique has been widely used on high-performance components, its impact may be more accentuated on cars than on bikes due to the different combustion dynamics. By focusing solely on reducing carbon buildup, this approach may result in delivering benefits without aiming to boost horsepower. Kudos to Bob Kelly III, who provided the inspiration.
insta pro
 
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spraying water mist into the intake of a motor running hard will clean the combustion chamber to like brand new.
On the road steam cleaning if you will.
Did this to my 2005 Prius, that motor was famous for carbon build up causing valve noise as they started to strike the piston top carbon on opening.
Quieted mine right down but I didn't take before and after pics. Mebby on an XS one day.
Caviat; Pour in water, hydrolock a cylinder and kiss your rod goodbye.
 
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gggGary said:
spraying water mist into the intake of a motor running hard will clean the combustion chamber to like brand new
Click to expand...
Yep, the old "water tune up" trick, been around for ages. As Gary noted, the application has to be mist-like and you gotta rpm the livin' daylights out of it.
 
Grimly said:
Dig up an old thread, add some meaningless drivel to it, and Bot City '23.
Did you know that, phonetically in French, Chat GPT sounds like "The cat has farted"?
Click to expand...
Good catch! I missed it entirely, I'll keep an eye on our new friend.
@Jim
IP is also India Avitar is on a motorcycle,
Not a slam dunk that it's illegitimate.
 
gggGary said:
Good catch! I missed it entirely, I'll keep an eye on our new friend.
@Jim
IP is also India Avitar is on a motorcycle,
Not a slam dunk that it's illegitimate.
Click to expand...
Saw that this morning and thought it odd... but his IP pings from India... which he claims, so I thought I'd give him the benefit of the doubt.
 

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