b&S vanguard backfires and has no power


Old 11-19-06, 03:42 AM
Thread Starter
Join Date: Nov 2006
Posts: 4
b&S vanguard backfires and has no power

I have simplicity lawn tractor with 16 hp bs vanguard V model 303777 type 012201 code 90030211. It allways back fired once or twice on shutdown. But just this week it backfired continuously on startup and when it ran. Also when the pto was engaged it had no power. I checked spark with automotive spark gap tool and spark appeared to be good over 20,000V. I also checked compresion and both cylinders were near each other and over 150 psi, if i remember corectly.

We took of air filter and front was black and oily. Local dealer parts guy said it sounded like the breather assembly so we replaced that. The old one leaked air when we tested it. But when we started it again still backfired and had now power.
Sponsored Links
Old 11-19-06, 03:44 AM
Thread Starter
Join Date: Nov 2006
Posts: 4
also some additional info

we check plugs they were black so we cleaned them up and checked and readjusted the gap.
Old 11-19-06, 01:42 PM
30yearTech's Avatar
Join Date: Oct 2006
Location: Central Texas
Posts: 1,176
I would check the flywheel key to make sure it is not sheared and causing the ignition timing to be too far advanced.

If timing key checks out alright, then I would check valve lash.
Old 11-19-06, 07:47 PM
cheese's Avatar
Forum Topic Moderator
Join Date: Jul 2001
Location: USA
Posts: 16,821
I'd replace the plugs first. If still no better, I'd look into the valve adjustments and then the ignition.

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Thread Tools
Search this Thread
Display Modes