14+ compression differences - Yamaha YFZ450 Forum : YFZ450, YFZ450R, YFZ450X Forums
 
LinkBack Thread Tools
post #1 of 11 (permalink) Old 06-25-2019, 07:23 PM Thread Starter
Junior Member
 
Join Date: Nov 2018
Posts: 20
14+ compression differences

So.. I guess my CPM1000 12.75 piston is actually 13.25:1 on a 14+ 450..

14+ have .009 longer stroke equivalent to a single layer of head gasket. People used to do SLHG on the older bikes. Half a point of compression per layer.

Correct me if I'm wrong but does that sound right?
16'450r is offline  
Sponsored Links
Advertisement
 
post #2 of 11 (permalink) Old 06-25-2019, 07:46 PM
Senior Member
 
Orange2014's Avatar
 
Join Date: Apr 2017
Posts: 465
.45 13.2


Sent from my iPad using Tapatalk
Orange2014 is offline  
post #3 of 11 (permalink) Old 06-25-2019, 07:48 PM Thread Starter
Junior Member
 
Join Date: Nov 2018
Posts: 20
So I probably need higher octane fuel than the 93 I've been running the last 30 hours.
16'450r is offline  
 
post #4 of 11 (permalink) Old 06-25-2019, 10:27 PM
Senior Member
 
Sheerider11's Avatar
 
Join Date: Feb 2014
Posts: 2,828
Quote:
Originally Posted by 16'450r View Post
So I probably need higher octane fuel than the 93 I've been running the last 30 hours.
If you didn't notice in 30 hours then your probably fine

Sent from my SAMSUNG-SM-G891A using Tapatalk
Sheerider11 is offline  
post #5 of 11 (permalink) Old 06-25-2019, 11:08 PM
Senior Member
 
Orange2014's Avatar
 
Join Date: Apr 2017
Posts: 465
14+ compression differences

Quote:
Originally Posted by 16'450r View Post
So I probably need higher octane fuel than the 93 I've been running the last 30 hours.


I would. Your combustion chamber is more efficient against detonation but that doesnít mean 93 is enough. I would run a blend close to 97 octane but a 50/50 blend 91/100 octane will probably be sufficient.


Sent from my iPad using Tapatalk

Last edited by Orange2014; 06-25-2019 at 11:11 PM.
Orange2014 is offline  
post #6 of 11 (permalink) Old 06-26-2019, 01:50 AM
Senior Member
 
Join Date: May 2017
Location: USA
Posts: 1,089
Is higher than 91 octane more aggressive/corrosive on metals compared to 91 octane?

2018 YFZ450R SE : warning labels removed, TMD case saver, GYTR aluminum frame skid with the bracket mod, thick helicopter tape here and there, some stickers, everything else stock stock stock like the dealer likes it.
PIN IT PIN IT !!! SCREW BREAK IN STEPS.

On deck.circle: VORTEX ECU/PEAK RACING MOUNT - YOSHI SLIP ON NO SPARKY.
yfzgambler is offline  
post #7 of 11 (permalink) Old 06-27-2019, 03:25 AM Thread Starter
Junior Member
 
Join Date: Nov 2018
Posts: 20
I wouldn't say higher octane fuel is corrosive. I've read here and there that Oxy fuels can be slightly corrosive to aluminum.

Seemed to be a grey area when it came to compression and octane needed. Picked up some c12 yesterday. Plan on trying it out to see if it runs any differently. Also installed an RpRace 45mm TB today. Hoping for good things.
16'450r is offline  
post #8 of 11 (permalink) Old 06-28-2019, 10:12 AM
Member
 
Tagels's Avatar
 
Join Date: Jun 2017
Location: Colorado
Posts: 81
I believe the M1000 is actually 12.5:1 on 09-13 and 12.75:1 on 14+. I could be wrong but I'm pretty sure the difference from the longer rod is only 0.25:1

2012 YFZ450R

LEVEL 4 Racing | WORCS Pro-AM

Check out my Youtube channel of racing content!
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
Tagels is offline  
post #9 of 11 (permalink) Old 06-28-2019, 11:02 PM
Senior Member
 
Orange2014's Avatar
 
Join Date: Apr 2017
Posts: 465
14+ compression differences

Quote:
Originally Posted by 16'450r View Post
So.. I guess my CPM1000 12.75 piston is actually 13.25:1 on a 14+ 450..



14+ have .009 longer stroke equivalent to a single layer of head gasket. People used to do SLHG on the older bikes. Half a point of compression per layer.



Correct me if I'm wrong but does that sound right?


It would be 13.2 if you shaved another .009 off your cylinder or cylinder head. I didnít really clarify that well. Your currently at 12.95:1. 12.7:1 if that particular piston is only 12.5 like Tagels said.


Sent from my iPad using Tapatalk

Last edited by Orange2014; 06-28-2019 at 11:06 PM.
Orange2014 is offline  
post #10 of 11 (permalink) Old 07-01-2019, 05:08 PM Thread Starter
Junior Member
 
Join Date: Nov 2018
Posts: 20
Being that a 2013 and 2014 both use the same part number Piston..

2013 being 11.4 and 2014+ being 11.8, the only difference being the rod length.

The 12.5 listed is for 04/05 engines. 12.75 for 06-13.

So on a 14+ with an M1000 piston, 13.2 sounds more realistic.
16'450r is offline  
post #11 of 11 (permalink) Old 07-01-2019, 05:32 PM
Senior Member
 
Orange2014's Avatar
 
Join Date: Apr 2017
Posts: 465
14+ compression differences

2013 is 11.6. 11.4 is old carb




Sent from my iPad using Tapatalk

Last edited by Orange2014; 07-01-2019 at 05:40 PM.
Orange2014 is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Yamaha YFZ450 Forum : YFZ450, YFZ450R, YFZ450X Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

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

Password:


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

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



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