Need to rethread a plug hole from a blown plug - Yamaha Grizzly ATV Forum
Off-Topic Discussion Discuss anything that is NOT GRIZZLY RELATED (or that we don't have a section for) here. Please post in the appropriate forum that relates to your topic. This way when someone (including us) comes here to look for answers, it will be a lot easier to find info.

LinkBack Thread Tools Display Modes
post #1 of 8 Old 02-12-2019, 01:58 AM Thread Starter
bradleyheathhays's Avatar
Join Date: Jun 2015
Age: 42
Posts: 69
Thanks: 0
Thanked 2 Times in 2 Posts
Rep Power: 48
Need to rethread a plug hole from a blown plug

Bought an '11 Vic with the 4.6L back in June and a few months back I tried to change out the plugs. All came out ok except for cyl 4 which only cranked out 1/4 turn. Had a shop take it out and they said they had to redo the threads. I've seen videos where you can remove a stuck plug by drilling into it somehow, but because this was in the 4 position and hard to get to I'm guessing they just power cranked it out. Not sure but I'm guessing those threads are compromised now.

Well, this past weekend that same plug blew out of cyl 4. Inspection reveals a coil and boot jammed up underneath the fuel rail and a plug that I fished out without any turning. When I go to install a new plug it just sits on top of the threads and turns without going in. So I guess what's happened is that the plug rotated most of the way out but when it got to the last couple threads the compression blew it out the rest of the way, and that it's just the top few threads in the hole that are damaged. Inspection of the plug reveals that most of the threads are intact except for the 2-3 that are closest to the element.

So my question is...should I try to fix this myself or just take it to a shop? Some kind of tap tool would probably fix it, but since it's the beginning threads that are boogered it'd probably have to start from the inside of the cylinder. I really don't have a clue as to how to approach this.
bradleyheathhays is offline  
Sponsored Links
post #2 of 8 Old 02-12-2019, 07:03 AM
Vincent's Avatar
Join Date: May 2017
Location: Northern Ontario Canada
Posts: 1,045
Thanks: 82
Thanked 532 Times in 353 Posts
Rep Power: 30
Definitely worth a try! Find a tap and give her a go. Put grease on hit to "catch" the metal chips.

Worse case the head will need to be removed and maybe a helicoil installed.

2009 Grizzly 550 Special Edition, Red Midnight Armour, EPS, 26"Pitbull Growler BG2.5 xor, on 12"polished alloy SE wheels with 1"spacers, Yamaha overfenders & windshield, Heat Demon grips & thumb warmers, 2500lbs Warn winch, two up seat / storage box, Moose rear bumper, Gold Plugs in diffs & engine, Pod Mod set to 45, COOP45 machined sheave (3:1), 18 gram weights, EPI Orange spring

Last edited by Vincent; 02-12-2019 at 07:08 AM.
Vincent is online now  
post #3 of 8 Old 02-12-2019, 02:10 PM
Join Date: Feb 2019
Posts: 8
Thanks: 1
Thanked 1 Time in 1 Post
Rep Power: 0
I would take it to a shop. Blowing plugs is a well know issue Fords have. Some thread inserts are stronger than others.
Jgar is offline  
Sponsored Links
post #4 of 8 Old 02-12-2019, 07:01 PM
jvictory1974's Avatar
Join Date: Sep 2013
Location: middle Tennessee
Age: 44
Posts: 1,853
Thanks: 963
Thanked 587 Times in 437 Posts
Rep Power: 74
This is a common problem with certain Ford V8s. Go to your local parts house and get a repair kit. Comes with everything you need to repair the hole except the spark plug.

08 700 EPS
27"BHOG's W/ITP SS112 rims
Ricochet full skids
1.5xxbillet spacers
1.5shimw/EPI purple spring
HMF XL pipe w/optimizer
Uni air filter
Moose front and rear bumpers
12" LED bar and Halos
Rotopax 3gal fuel cell
Yami overfenders
Yami hand guards Yami rear box
Warn XT2.5 winch w/syn. rope
LED reverse light
ODI grips
Rhino axles
Wetsounds Stealth6 soundbar
Rox footpegs
jvictory1974 is offline  
post #5 of 8 Old 02-13-2019, 03:59 AM Thread Starter
bradleyheathhays's Avatar
Join Date: Jun 2015
Age: 42
Posts: 69
Thanks: 0
Thanked 2 Times in 2 Posts
Rep Power: 48
Thanks for all the advice. If this was where I could get to it I might try to do this myself, but since it's so far back it'll be a lot less headache to take it to the shop. Local guys charging $99 an hour. Is that what shop rates are these days?

What's the best kind of thread inserts? Are there different kinds in the heli coil style? I've heard of a newer one called Time-Sert but don't know if they have a higher success rate. Someone familiar with doing heli coils says lots of times the next time the plugs are removed the coil comes right out with it.
bradleyheathhays is offline  
post #6 of 8 Old 02-13-2019, 04:46 AM
Join Date: Jun 2017
Location: Alaska
Posts: 64
Thanks: 33
Thanked 10 Times in 9 Posts
Rep Power: 23
Helicoils definitely have their place. I'm not sure a sparkplug hole is one of those. This is a much better solution.
I strongly suggest removing the head so you can be positive that the drill is correctly lined up. It would be real easy to oval out that hole or not line the tap up right while contorted into the engine bay. If you aren't tooled up with torque wrenches and basic hand tools, a reputable shop would end up saving you money over time. Especially if you end up doing it yourself twice. Upside is getting familiar with the inner working of your ride.....

2013 GRIZZ 700 EPS

Tracen8r is offline  
post #7 of 8 Old 04-11-2019, 07:27 PM
Join Date: Apr 2010
Location: Phelps NY
Age: 66
Posts: 607
Thanks: 25
Thanked 133 Times in 68 Posts
Rep Power: 111
I have had good luck with this, if the threads can still be used, or there is a problem with the plug wanting to cross thread. You slide it into the plug hole, expand it into the good threads and then screw it out.
Sealey MS002 Reverse Action Spark Plug Thread Chaser 12mm
Policy Peddler is offline  
The Following User Says Thank You to Policy Peddler For This Useful Post:
monksblood (04-13-2019)
post #8 of 8 Old 04-14-2019, 07:48 PM
Join Date: Apr 2019
Posts: 6
Thanks: 0
Thanked 1 Time in 1 Post
Rep Power: 0
Take the head off, Have a welder TIG weld and re-drill and tap the hole. Will be good as new.
GrizzlyATV is offline  

  Lower Navigation
Go Back   Yamaha Grizzly ATV Forum > General Forums > Off-Topic Discussion

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode

Similar Threads
Thread Thread Starter Forum Replies Last Post
cyl misfire and coolant in the plug well bradleyheathhays Off-Topic Discussion 9 11-16-2018 08:58 AM
Spark plug is out... Grizzlyhunt Grizzly Talk 18 01-16-2010 10:17 AM
Mad Mike Grizzlyhunt Grizzly Talk 44 12-30-2009 12:29 AM

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 On
Pingbacks are On
Refbacks are On

For the best viewing experience please update your browser to Google Chrome