Corey Posted December 21, 2015 Share Posted December 21, 2015 I recently removed the throttle bodies and looked down into the intake. There appears to be a lot of grime carbon deposits on the back side of the intake valves. How do I get rid of this grime and how do I avoid it for the future? Because it is a PFI system, do you think that this product CRC 1-Tank Power Renew or CRC Intake Valve Cleaner would work to clean the back sides of the intake valves? Thanks. Link to comment Share on other sites More sharing options...
ChiefGodzilla Posted December 21, 2015 Share Posted December 21, 2015 With PFI any cleaner you use will pound into the intake valves, it is the design of the system. Hell, quality gas might get rid of some of the gunk. Use what you think is best, but if it is truly stuck on there manual cleaning is the only true method. Also for just plain dirty looking with no major build up, seafoam and MM oil gets my vote. As for preventing build up disconnect your oil breather from your airbox, and use a filter that vents to atmo. and check you valve oil seals for excessive wear allowing oil to leak down the stems and coat the valves. If you have a endoscope check the Pistons for excessive deposits to see if oil has leaked past the valves and burned in the piston. Though most likely not, unless she has been running oddly latly. Just my 2 cents. Blade Link to comment Share on other sites More sharing options...
Member Contributer Switchblade Posted December 21, 2015 Member Contributer Share Posted December 21, 2015 What he said ^^^^ .... Link to comment Share on other sites More sharing options...
Corey Posted December 21, 2015 Author Share Posted December 21, 2015 I've used nothing but Chevron brand Ethanol Free 92 Octane gas in the bike. Obviously that is not doing the trick. Does anyone know if the ethanol free stuff contains the same detergents, etc. that the ethanol variety contains? Link to comment Share on other sites More sharing options...
Member Contributer BusyLittleShop Posted December 21, 2015 Member Contributer Share Posted December 21, 2015 Additives will not do the trick if the problem is leaking valve guide seals... one indicationis white smoke on start up and another is a puff of smoke during down shifts... the grime is actually burnt oil... Link to comment Share on other sites More sharing options...
Corey Posted December 22, 2015 Author Share Posted December 22, 2015 I don't get either white smoke on start up nor puff of smoke during down shifts. Still wondering about that CRC 1-Tank Power Renew for the VFR. Link to comment Share on other sites More sharing options...
Member Contributer Switchblade Posted December 22, 2015 Member Contributer Share Posted December 22, 2015 I gonna say bad gas . Really dont know the best way to clean but gonna search the internet for info. I do remember a water injection system that would clean the combustion camber . Link to comment Share on other sites More sharing options...
Knight Posted December 22, 2015 Share Posted December 22, 2015 Maybe I missed any post on this: Have the valves clearances been checked? Is this goo necessarily a problem? If all the checks above go good, can it not be harmless caked on fuel? What are your long-term riding habits? Do you do a lot of slow city driving? I wonder (I don't know personally) if the offending goo can be burned off from running it hard, and maybe that is the only thing that can or should be done. Link to comment Share on other sites More sharing options...
ChiefGodzilla Posted December 23, 2015 Share Posted December 23, 2015 A Italian tune up Take her out and run her out in each gear, maybe even let her bounce of the Revline a few times. Link to comment Share on other sites More sharing options...
JNBarrett Posted December 23, 2015 Share Posted December 23, 2015 I'd have a little concern if it were my bike, but I wouldn't be freaking out either yet without some further investigation. I'd expect this type of grime potentially on the exhaust valves, but it can happen on the intakes on a direct injection system where the fuel detergents / additive never see the inlet side of the intake valves. Unfortunately, these engines on the VFR are not direct injection and the fuel DOES pass over the inlet side of the intake valves. I'd take a closer look to exactly what the grime is on the back of those valves - if it's carbon / ash your valve guides could be getting worn, the valve seals starting to leak, or your valve clearances may just need and adjustment. You can burn a valve by allowing carbon deposits to build which prevent the valve from seating properly. A valve must make proper full contact with the seat to dissipate heat from combustion. Checking it now is cheaper than burning a valve and having part of it fall into the combustion chamber. :) Link to comment Share on other sites More sharing options...
Member Contributer BusyLittleShop Posted December 23, 2015 Member Contributer Share Posted December 23, 2015 I don't get either white smoke on start up nor puff of smoke during down shifts. Still wondering about that CRC 1-Tank Power Renew for the VFR. If gas (which is a petroleum distillate) has had no cleaning effect then I doubt another petroleum distillate like CRC will do any better... Link to comment Share on other sites More sharing options...
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