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Stella engine racing after spark plug change
Posted: Wed Dec 23, 2015 1:16 pm
by RoaringTodd
Last week my 2t Stella wouldn't start. She ran perfectly before that. I tested for spark, found none, so changed the spark plug. Gapped to .7 as per the manual. Same kind of spark plug as the previous one.
Now the engine races after riding around the block. I thought the spark plug wasn't in snug enough causing an air leak. Checked that with choke cleaner and removed and reinserted the plug. Engine still raced.
What gives? What in a spark plug change would cause the engine to race?
Posted: Wed Dec 23, 2015 3:00 pm
by avescoots1134
Pull the airbox lid and filter and make sure everything is closing correctly. Then you can check your jets if that isn't the case. Then go chasing air-leaks
Posted: Mon Mar 14, 2016 6:44 pm
by RoaringTodd
Update - it was the carburetor. Had my dealer take a look and he cleaned up the carburetor and worked his secret magic. I've never had her run this well before. What I thought was normal "Stella ya know" was not it. It's like a whole new scoot.
Posted: Tue Mar 15, 2016 10:44 am
by RoaringTodd
Forgot to add - the head was leaking a little bit. He machined the head smooth and put on a new gasket and torqued down everything tight.
Posted: Wed Mar 16, 2016 12:58 am
by fisher1
Wondering ..... what plug did they install / were you using? The Phila shop put a NGK B6ES in mine many years ago when I had it in for the 500 mi. warranty checkup. That's good for center city, but I'm in the 'burbs where I do a lot more sustained running and it showed up as increased temps on the CHT. So I swapped it out for a cooler B7ES which settled it back down to normal temps. Just FYI.
Posted: Tue Mar 22, 2016 11:40 am
by RoaringTodd
Yeah it's the B7ES.
However have been having problems with plugs fouling after only a few hours on the plug. We're talking wet black oil covered plugs. :facepalm:
Stellas. Gotta love them.
Posted: Tue Mar 22, 2016 9:38 pm
by az_slynch
RoaringTodd wrote:Yeah it's the B7ES.
However have been having problems with plugs fouling after only a few hours on the plug. We're talking wet black oil covered plugs. :facepalm:
Stellas. Gotta love them.
Still running the autolube? Does she seem to smoke a lot at idle? If so, you might have the pump disassembled and replace the O-rings that go on the pump's valve body. Besides that, your mixture might need to be leaned out a touch with your air leak fixed.
If you're premixing, what's your ratio, what's your jetting and what your mix screw set at?