Benefits of a ported and polished head on a klr with light modifications? - Kawasaki KLR 650 Forum
1987 to 2007 Wrenching & Mods For maintaining, repair or modifications of Generation 1 KLR's. 2007 and earlier.

 6Likes
Reply
 
LinkBack Thread Tools Display Modes
post #1 of 16 Old 09-25-2018, 10:27 PM Thread Starter
Neutral
 
Join Date: Sep 2018
Location: I plead the 5th
Posts: 1
Benefits of a ported and polished head on a klr with light modifications?

So just to start this off this is my first post on this forum so sorry if this has been asked before.

I have a 2007 klr with an fmf power bomb header, big gun slip on, 142 main jet, klx needle, 22 cent mod, eagle mike doohickey, and some vents in the air box cover. I was wondering if it would be a good idea to port and polish the head with my setup? Would it help with throttle response any? My klr is an oil burning pig and its my first bike so i'm not trying to make insane power. I just want to know if there would be a feel able difference.
BasedDragon is offline  
Sponsored Links
Advertisement
 
post #2 of 16 Old 09-26-2018, 07:57 AM
2nd Gear
 
shaky6's Avatar
 
Join Date: May 2018
Location: Dothan, AL
Posts: 167
Garage
3 or 4% maybe? What's that on 38hp? 1.5hp tops.

1986 Honda TLR 200 Reflex
2002 Ducati Monster 750S < -- For Sale
2005 Kawi KLR 650
shaky6 is offline  
post #3 of 16 Old 09-26-2018, 08:36 AM
Moderator
 
klr4evr's Avatar
 
Join Date: Mar 2007
Location: Fort Sask , Alberta, Canada
Posts: 3,450
Garage
Send a message via Skype™ to klr4evr
Quote:
Originally Posted by BasedDragon View Post
I was wondering if it would be a good idea to port and polish the head with my setup? Would it help with throttle response any? My klr is an oil burning pig and its my first bike so i'm not trying to make insane power. I just want to know if there would be a feel able difference.
Firstly welcome to the forum.

If you can do the porting and polishing yourself and it doesn’t cost you anything then go for it. Everything helps a little. However, if it comes at a cost I think your money would be better spent on a 685 kit which will may also solve your oil burning problem.
DPelletier likes this.

My Kaw Barn - 2004 KLR, 2006 Concours (sold), 1997 Bayou 400.

"It's a friggen motorcycle, it's not supposed to be comfortable, quiet or safe. The wind noise is supposed to hurt your ears, the seat should be hard and riding it should make you shit your pants every now and then. "

<--- Please fill in the 'Location' on your personal profile page. User CP/Edit Your Details

This information makes it much easier for other members to answer/comment on your posts.
klr4evr is offline  
 
post #4 of 16 Old 09-26-2018, 09:54 AM
4th Gear
 
Join Date: Aug 2010
Location: Kelowna, B.C.
Posts: 2,232
I doubt you'd feel the difference. Sounds like you should save up for the 685 instead.

Dave
DPelletier is offline  
post #5 of 16 Old 09-26-2018, 10:25 AM
5th Gear
 
Join Date: Jan 2011
Posts: 4,183
Porting and polishing an otherwise-mostly-stock KLR650 engine?

You stand on the precipice of an abyss of severe diminishing returns, as in benefits far less than the effort obtaining them, IMHO.

Porting and polishing, according to conventional wisdom, is among the LAST hop-up options, in contrast to the FIRST. Only a highly-modified engine can benefit within any economy-of-scale from porting and polishing.

Don't know your definition of, "Throttle Response." If the term means the time interval between twisting the handgrip throttle open and the opening of the carburetor slide, porting and polishing has zero, nada, zilch, zed effect. A slide (versus a stock CV) carburetor offers improved throttle response within this context, but sacrifices some CV versatility characteristics (an accelerator pump on a slide carburetor compensates somewhat for this loss).

And . . . as posted above, it's a KLR! Sub-40 horsepower; even highly modified; hardly a David to slay the Goliaths (e.g., KTM690; nearly 70 hp out of the box).

Yet, we've all seen, "The World's Fastest Indian" movie! Keep in mind, the title motorcycle was essentially purpose-built, involving years of effort, tens of thousands of dollars, and, I think, a DIVORCE!

DISCLAIMER: Above post contains my often-ridiculous opinions, only.

Last edited by Damocles; 09-26-2018 at 10:30 AM.
Damocles is offline  
post #6 of 16 Old 09-26-2018, 11:59 AM
4th Gear
 
Join Date: Aug 2010
Location: Kelowna, B.C.
Posts: 2,232
Quote:
Originally Posted by Damocles View Post

DISCLAIMER: Above post contains my often-ridiculous opinions, only.
....you're going to use that from now on, aren't you? LOL


Dave
pdwestman and Damocles like this.
DPelletier is offline  
post #7 of 16 Old 09-26-2018, 01:07 PM
2nd Gear
 
Join Date: May 2018
Location: Michigan
Posts: 259
why not just go big bore and a turbo? I think about the only mod that would give this engine a significant seat of the pants power boost is just that. More boost..

Never pick a fight with an old man.. If he's too old to fight, he'll just kill you..
PaddyD is offline  
post #8 of 16 Old 09-26-2018, 01:56 PM
4th Gear
 
Join Date: Aug 2010
Location: Kelowna, B.C.
Posts: 2,232
Quote:
Originally Posted by PaddyD View Post
why not just go big bore and a turbo? I think about the only mod that would give this engine a significant seat of the pants power boost is just that. More boost..
the easiest and best way to get 60+ hp from a KLR is to remove the gas cap and replace everything below it with a KTM690R! ;-)

Dave
roadrash83 likes this.
DPelletier is offline  
post #9 of 16 Old 09-26-2018, 09:36 PM
2nd Gear
 
Join Date: May 2018
Location: Michigan
Posts: 259
Quote:
Originally Posted by DPelletier View Post
the easiest and best way to get 60+ hp from a KLR is to remove the gas cap and replace everything below it with a KTM690R! ;-)

Dave
I concur, hence the sarcastic comment about the turbocharger.. As the old saying goes, "you can put lipstick on a pig, but it's still a pig."
DPelletier likes this.
PaddyD is offline  
post #10 of 16 Old 09-27-2018, 02:02 PM
OverDrive
 
Join Date: Nov 2009
Location: Lander, Wyoming
Posts: 5,239
Quote:
Originally Posted by Damocles View Post
Porting and polishing an otherwise-mostly-stock KLR650 engine?

You stand on the precipice of an abyss of severe diminishing returns, as in benefits far less than the effort obtaining them, IMHO.

Porting and polishing, according to conventional wisdom, is among the LAST hop-up options, in contrast to the FIRST. Only a highly-modified engine can benefit within any economy-of-scale from porting and polishing.


DISCLAIMER: Above post contains my often-ridiculous opinions, only.
BasedDragon,

In my opinion, Damocles actually has that statement backwards. If one talks to or reads from expert, high-performance engine builders, one will learn that properly porting & polishing of the cylinder head should be the First thing done. They flow test every change they make to the ports. Part of what makes the 1st one very pricey.

Everything else performed to the engine is then chosen to enhance the potential gains of the porting & polishing to maximize the now added potential flow rate of the modified ports.

Take the time to read and understand what is printed over here,
https://www.klrchris.com/klr650-small-port-head/

Then send Chris an e-mail and inquire as to how much he might charge to make a duplicate of his cylinder head out of yours.
rebar likes this.

pdwestman
Modify at "YOUR OWN RISK"!

Still riding my 1987 KL650-A1. 84,000+ miles & counting

Last edited by pdwestman; 09-27-2018 at 02:07 PM.
pdwestman is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Kawasaki KLR 650 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:
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
Display Modes
Linear Mode Linear Mode



Similar Threads
Thread Thread Starter Forum Replies Last Post
Polished sprockets cjk911 1987 to 2007 Wrenching & Mods 3 05-25-2017 03:54 PM
Modifications for KLR!!! ryanrocher KLR & Other Motorcycle Related Discussion 23 08-18-2010 05:58 PM
My modifications on the cheap! Ne14abeer 1987 to 2007 Wrenching & Mods 2 06-26-2009 12:46 PM
Aesthetic body modifications Unividual 1987 to 2007 Wrenching & Mods 4 08-22-2007 08:17 AM
Merlite modifications armountainbiker KLR & Other Motorcycle Related Discussion 2 02-17-2007 12:26 AM

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