plugs are a grey yellow colour

[chris6888]

On my 83 katana the plugs are a grey yellow colour. I have put new o rings on the intake boots the boots look good almost new. I rebuilt the carbs as per the tutorial on this site. I have synced the carbs i bought the oring kit off of the link on this site. As i am driving the bike seems to buck a bit like its not getting fuel or its sucking air. Any thouhts

[elrico]

Saw dry yellow/green/grey color tinted spark plug on KLR 250 @6k mi/6yrs old. Engine a bit hard starting and slightly uneven idle,but ran strong otherwise.Replaced w/new plug even though it appeared not so bad externally, but internally may be fatigued ,no issues thereafter. Been using Stabil fuel stabilizer for 6 yrs ,just for info.sake. Are your spark plugs brand new or been using same ones throughout motorcycle problem/issues? Having any elect.charging/battery/problems.? Tell more,as you are able to later.

[chris6888]

Put new plugs in and did it put old ones back in and it did the same thing. Having some problems with battery not holding charge all the time.

[elrico]

Yellow plug insulator deposits used to be prevalant w/excessive highly/leaded fuel/gas ratios. Check air filter condition for contamination,gas/oily residues etc. is air filter OEM, proper type/style/size fitted properly or aftermarket style ,excessively "oiled"? Do you have known fat blue sparks at all sparkplugs? Known good battery w/known checked out electricial charging system? We need to know these things also.

[tom203]

On my 83 katana the plugs are a grey yellow colour. I have put new o rings on the intake boots the boots look good almost new. I rebuilt the carbs as per the tutorial on this site. I have synced the carbs i bought the oring kit off of the link on this site. As i am driving the bike seems to buck a bit like its not getting fuel or its sucking air. Any thouhts

Check petcock for good fuel delivery-try running on prime position and see if that helps. Does it "buck a bit" at all speeds? How is your idle when warm? In further post, you said you had battery problems- straighten this out as the ignitor and coils need a certain power level to function right.

[chris6888]

my petcock is new and yes it seems to buck at all speeds but also seems to lose power when i am in 5th gear

[chris6888]

It seems to also hesitate when i try to accelerate in 5th gear. Also i have a small fuel filter should it be there

[hampshirehog]

There's no filter in line as standard - could be starving the carbs (and your symptoms are fuel starvation). Also worth checking that the fuel cap is letting air in the top of the tank and not creating a vacuum. Those and check your tap.

Just saw your thread looking for an airbox. You are running with an airbox fitted aren't you?

[chris6888]

no the bike came with k&n filters

[tom203]

no the bike came with k&n filters

When you "rebuilt" the carbs, did you take note of jet sizes in case PO changed things when he added K & N's ?

[chris6888]

no i did not check the jets but i will check them

[elrico]

I rebuilt carb set on 78 CB750F yrs. ago.Being so forewarned about not to over tighten jets/snap them etc.I erred so that not too many miles later.bike ran somewhat as you describe yours to be doing.Off came carb set and lo and behold found 0ne main jet lying at bottom of float bowl.Just don' know till ya look/see like all say. OEM exhaust system or aftermarket?Check valve lash/adj.since eventually you are heading in that direction anyway..Be patient with self,bike came the way it is ,take time it shall come together nice.

[trippivot]

if the plugs are grey yellow --- that is what burnt aluminum looks like.

The only time I have seen those colors are when a LTD 750 put a hole in the piston crown from lean misfire...

[elrico]

Checks/corrections..maybe catch and avert bugger problem(s). Old Honda #3 piston crown let go at 70mph , huge white trail of smoke behind bike,007 style.Even so, we limped home 5mi. Bought old/unknown bike ,out for 3rd short ride,gettin a feel for things,she showed how she felt..long ago and far away.Got to ride her for 48 total mi up to that point.After "fix' we motored for 26k mi,she went to new owner w/no problems. Chin up,chris6888 the best is yet to come.

[hampshirehog]

You need to check those carbs before riding any further. She's running lean and may be suffering engine damage as a result.