Fouling plugs

[viclioce]

My Ace B+, which I replaced the broken kick shaft bearing retainer, is now fouling plugs.

Yesterday, I pulled the carb, found the pilot jet clogged, but the main jet open.She has the OEM 20mm mikuni, a 90 main jet, I believe a 30 pilot jet, (hard to read) and a fuel mixture at 32:1, with Yamaha 2R oil. Also running a B8HS plug.

After carb assembly & installation, it started & idled fine and for the first few seconds would rev up nicely. Then, putting her into gear, it wouldn’t rev up and the plug fouls out in less than a minute, the plug literally turning black!

I never had an issue with this configuration in the past, so I’m looking for ideas on why it’s now fouling plugs almost immediately. Thanks! Victor

[thrownchain]

Air filter good? Exhaust pipe not plugged? Timing set correctly?

[viclioce]

I reset the points before starting it yesterday just to make doubly sure the points were correctly gapped. The exhaust went through a typical BBQ process before the pipe was repainted & installed. The air filter is a K&N pod filter on the back of the carb, and should for all intents & purposes make it run leaner & not richer.

So I’m open to other ideas. As I said, it was running fine right up until the kickshaft bearing retainer broke. Victor

[matt glascock]

Just a thought Victor. Are you letting the bike get really good and warmed up at Idle speed only - to the tune of a couple or three minutes at idle? Sounds like everything else is ship-shape. Give it a try.

[Dale]

Are you really running a B8HS? That is the wrong plug if you have a stock head on it. Should be a B8S.

[matt glascock]

Yikes Dale, I missed that. B8HS has too long of a reach. I hope that its not long enough to ding the piston crown!

[Bullfrog]

Might have nicked the clutch side crank seal when reassembling - which would allow transmission oil to be drawn in to the bottom end. Pressure test or watch for constant dropping of transmission oil level (should be pretty smokey exhaust too). If that is the problem, don't feel like the Lone Ranger. Been there, done that. (Ran good before splitting the cases, runs bad after reassembly . . . ouch.) Per Dale - proper plug for stock 100-B+ is a B8S.
Ed

[Joe Ormonde]

When you assembled the Engine was grease used on the Crank main bearings? If so, until it works it`s way out you will have a problem. Spark plugs don`t like STP, Grease and most of all Teflon Grease. The only real problem installing a tad longer reach B8HS spark plug is this: The exposed threads over time become encased in carbon and prevent the Plug from coming out. So you force it out and it`s STRIPPED THREAD TIME! We all hope it`s not drinking oil from a seal or case but if it is these things happen! Joe.

[matt glascock]

Great info, Joe. I have heard of holed pistons and such. I ran too long a plug in my CW briefly just to get back to the trailer but before I fired up, I kicked it over slowly with the kill switch depressed and listened/felt for impact. I replaced the plug immediately upon arrival. No problem. That makes sense with the carbon encasement and strippage. Grrr. Thanks.

[viclioce]

Crap! I’ll take the plugs back & exchange them! I’ll also check the clutch side crank seal. Thanks everyone. Victor

[Bullfrog]

Your Road Toads can use the B8HS plugs.

Ed

[viclioce]

Funny how both Aces had the same plug in them. But, the did come from the same owner. Guess he figured one was as good as the other!

I bought 4 of these plugs. I’ll save them for the Toad. And I bought 4 B9HS for the CW so I can use those for both Wombats since they have the same heads! I’ll just go buy 4 more B8S plugs. Victor

[viclioce]

I ordered a box of B8S and will be picking them up this afternoon! Victor

[viclioce]

Plugs were delayed but I finally got them last night! Put one in the B motor today and I’ll put another in the B+ motor! Victor