Spark plugs - Yamaha Raptor Forum
LinkBack Thread Tools Display Modes
post #1 of 3 (permalink) Old 07-05-2019, 08:24 AM Thread Starter
Wko78ms's Avatar
Join Date: Jul 2018
Posts: 52
Spark plugs

Hello, just wondering the heat range people are running. I have hot cam 2, +3 throttle body and 12:1 piston. I run 14:1 at cruising and 13-13:5 under load for fuel ratio. Currently I'm using a 9 on the heat range but thinking I need to go back to an 8. I'd say my fuel is perhaps little on the lean side if not perfect, but my plug is indicating that I'm running rich(little on the dark side). Everyone I can find runs the 9 plug, is this to accommodate pump gas with this combo? I always run Sunoco 110. Any thoughts? Thanks!
Wko78ms is offline  
Sponsored Links
post #2 of 3 (permalink) Old 07-06-2019, 11:37 AM
Senior Member
Join Date: Oct 2016
Location: Georgia
Posts: 176
I use the stock plug in mine, I have the same mods, I run a 96 octane. I mix 110 or AV has with 93 octane. I have never had any issues with detonation.
418Stroker is offline  
post #3 of 3 (permalink) Old 07-06-2019, 07:20 PM
Lifetime VIP

Join Date: Oct 2009
Location: Springfield, OR
Posts: 2,391
Send a message via AIM to t web2007
You are at kind of a sticky point. You don’t need 110 octane leaded fuel at 12:1 compression and probably don’t need the colder plug. Generally you need the colder plug and high octane fuel at higher compression ratios.

2015 700Rse
Fci, PC5F/I, monster exhaust, +2 Cuervo head, HDD5150, 54mm throttle body, 105.5 14:1, +8 swingarm.
08 yfz450se
Sparks big core, k&n no lid, yz needle, yz timing mod, +4 swingarm.
Cuervo 870, lectron, msd, monster megs, single a-arm lightened chasis, +14 swingarm.
Cuervo 930, lectron, msd, db fab titanium chasis.

Last edited by t web2007; 07-06-2019 at 07:22 PM.
t web2007 is offline  

Quick Reply

Register Now

In order to be able to post messages on the Yamaha Raptor Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:


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

Posting Rules  
You may post new threads
You may 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