Author Topic: 266 backfires and then dies.  (Read 1785 times)

0 Members and 16 Guests are viewing this topic.

Offline raumato01

  • 4 cube
  • **
  • Posts: 37
  • Karma: 2

  • Total Badges: 17
    Badges: (View All)
    Level 4 Fourth year Anniversary Third year Anniversary Second year Anniversary One year Anniversary Karma
266 backfires and then dies.
« on: August 09, 2015, 06:23:05 am »
I just bought a 266 project, it was complete so I started it up and it ran for a few minutes nicely then it started backfiring and then it died. It started again and idles nicely but when you give it throttle the backfiring started again.
I'm thinking either air leak , seals or maybe an electrical short? Any thoughts before I start tearing it apart?

Share on Facebook Share on Twitter


Offline jmester

  • Global Moderator
  • Nitro Hotsaw
  • *******
  • Posts: 2106
  • Karma: 171
  • Location: MD

  • Total Badges: 36
    Badges: (View All)
    Tenth year Anniversary Nineth year Anniversary Eighth year Anniversary Seventh year Anniversary Sixth year Anniversary Level 6
Re: 266 backfires and then dies.
« Reply #1 on: August 09, 2015, 10:45:40 am »
It sounds to me like an ignition problem.
FEAR NO TREE. FEAR GOD.

Offline Cut4fun .

  • Administrator
  • Nitro Hotsaw
  • *******
  • Posts: 23708
  • Karma: 664
  • OHIO REDNECK Saw Repair Getter Done
    • Redneck Chainsaw Repair

  • Total Badges: 53
    Badges: (View All)
    Tenth year Anniversary Nineth year Anniversary Level 8 Apple User Eighth year Anniversary 20000 Posts
Re: 266 backfires and then dies.
« Reply #2 on: August 09, 2015, 11:56:19 am »
Start cheap. Try a known good plug.  Had this type deal happen to just be a bad plug before. If you get lucky. ;)

Offline raumato01

  • 4 cube
  • **
  • Posts: 37
  • Karma: 2

  • Total Badges: 17
    Badges: (View All)
    Level 4 Fourth year Anniversary Third year Anniversary Second year Anniversary One year Anniversary Karma
Re: 266 backfires and then dies.
« Reply #3 on: August 09, 2015, 02:12:15 pm »
Cheers for the replies .Changing the plug was the first thing I did and nothing changed , so next I go over the wiring and see if there are any cuts or nicks in it? What are the chances of the flywheel being an issue?

Offline jmester

  • Global Moderator
  • Nitro Hotsaw
  • *******
  • Posts: 2106
  • Karma: 171
  • Location: MD

  • Total Badges: 36
    Badges: (View All)
    Tenth year Anniversary Nineth year Anniversary Eighth year Anniversary Seventh year Anniversary Sixth year Anniversary Level 6
Re: 266 backfires and then dies.
« Reply #4 on: August 09, 2015, 02:27:58 pm »
How does the magnet look? My guess would be the module. I would also check your air gap.
FEAR NO TREE. FEAR GOD.

Offline Eccentric

  • Moderator
  • Nitro Hotsaw
  • *******
  • Posts: 2117
  • Karma: 217
  • Magnesium and Iron.
  • Location: Northwestern Wyoming

  • Total Badges: 37
    Badges: (View All)
    Tenth year Anniversary Nineth year Anniversary Eighth year Anniversary Seventh year Anniversary Sixth year Anniversary Fifth year Anniversary
Re: 266 backfires and then dies.
« Reply #5 on: August 09, 2015, 06:09:47 pm »
Could also be a sheared (or missing) flywheel key.  If the FW is not positioned right the timing will be off...

Offline raumato01

  • 4 cube
  • **
  • Posts: 37
  • Karma: 2

  • Total Badges: 17
    Badges: (View All)
    Level 4 Fourth year Anniversary Third year Anniversary Second year Anniversary One year Anniversary Karma
Re: 266 backfires and then dies.
« Reply #6 on: August 09, 2015, 06:22:53 pm »
Cool, I'll check the gap and then the flywheel and report back.

Offline raumato01

  • 4 cube
  • **
  • Posts: 37
  • Karma: 2

  • Total Badges: 17
    Badges: (View All)
    Level 4 Fourth year Anniversary Third year Anniversary Second year Anniversary One year Anniversary Karma
Re: 266 backfires and then dies.
« Reply #7 on: September 19, 2015, 10:58:56 pm »
Well it isn't the flywheel, took it to a small motor mechanic to get the flywheel off and he said the compression was low which could let unburnt gas through. So much for a cheap project, I might put a new meteor piston in it.

Offline wild262

  • 6 cube
  • ****
  • Posts: 161
  • Karma: 29

  • Total Badges: 14
    Badges: (View All)
    Third year Anniversary Second year Anniversary 100 Posts Level 3 One year Anniversary 50 Posts
Re: 266 backfires and then dies.
« Reply #8 on: September 20, 2015, 09:39:44 am »
     Not sure that's the problem.  What was the compression reading?  Did he show or tell you?  I have had saws that ran fine at 115-120 lbs. outside of being alittle low on power.  Most dealers would say to that, "you need a rebuild".  You may have other issues in addition to that.  Check the ignition system first, esp. the coil before you spend your money on a rebuild, or another saw.  Could be a carb issue as well.  Just don't be to hasty taking a dealers word for it.  Some are very dishonest and just want to make a sale.  Good luck.

Offline raumato01

  • 4 cube
  • **
  • Posts: 37
  • Karma: 2

  • Total Badges: 17
    Badges: (View All)
    Level 4 Fourth year Anniversary Third year Anniversary Second year Anniversary One year Anniversary Karma
Re: 266 backfires and then dies.
« Reply #9 on: September 20, 2015, 06:22:05 pm »
Thats good advice, but I should have mentioned the guys not a dealer he has a little workshop and just services outdoor gear. He pointed out theres a nick in one of the coil wires which might short out and said it will need at least new rings although it does still run ok but like you said down on power.

I think you're right and will try heat shrinking the nicked wire first and then work up from there.


 

Related Topics

  Subject / Started by Replies Last post
17 Replies
2026 Views
Last post February 12, 2013, 07:48:58 am
by bassman
9 Replies
1479 Views
Last post October 26, 2013, 10:25:33 pm
by 660magnum
21 Replies
1669 Views
Last post April 11, 2014, 08:58:12 pm
by 3000 FPS
7 Replies
732 Views
Last post December 01, 2014, 11:04:56 pm
by 660magnum
7 Replies
1003 Views
Last post October 29, 2014, 03:58:59 pm
by Fish
6 Replies
860 Views
Last post February 27, 2015, 02:12:00 pm
by adriandwor
6 Replies
2831 Views
Last post January 08, 2016, 07:31:28 am
by 67L36Driver
1 Replies
407 Views
Last post December 01, 2015, 11:24:23 pm
by Cut4fun .
2 Replies
404 Views
Last post August 17, 2019, 10:53:09 pm
by Midpines
1 Replies
465 Views
Last post April 01, 2022, 07:50:25 am
by Cut4fun .