Advanced Search

The Green Industry's Resource Center

Old 10-08-2007, 11:02 PM
Godfather Godfather is offline
LawnSite Member
Join Date: Sep 2006
Location: Columbus, Ohio
Posts: 186
Spark Arrestor

My (trusted) dealer told me that if you take them out the cylinder, and exaust port will carbon up instead, is this true? He said that it may have something to do with backpressure. Any mechanic Know?
Reply With Quote
Old 10-09-2007, 12:02 AM
Restrorob's Avatar
Restrorob Restrorob is offline
LawnSite Fanatic
Join Date: Apr 2005
Location: Show'n my truck off !
Posts: 11,026
I believe your (trusted) dealer has that back-ward's, Leaving them in causes more back pressure (exhaust restriction) thus more carbon build-up.

Get them out of the way and the exhaust moves out of the port quicker thus less carbon deposits.

Disclaimer; I am no two stroke joke.
Originally Posted by piston slapper View Post
You never learn anything until you admit you don't know it all...
Originally Posted by MannsLawnService View Post
some times the man in my mirror isn't so smart...
"Why go out preserved when you can go out beat up, worn out, sliding in sideways screaming, Holy Sh!t What A Ride" !!!

Last edited by Restrorob; 10-09-2007 at 12:04 AM. Reason: Disclaimer
Reply With Quote
Old 10-09-2007, 01:36 AM
Breezmeister's Avatar
Breezmeister Breezmeister is offline
LawnSite Bronze Member
Join Date: Jul 2007
Location: South Jersey
Posts: 1,422
Originally Posted by Godfather View Post
My (trusted) dealer told me that if you take them out the cylinder, and exaust port will carbon up instead, is this true? He said that it may have something to do with backpressure. Any mechanic Know?
FWIW, chances are you will never find a carboned up exhaust port on a chain saw because it is almost always run at WOT. Back pack blowers, on the other hand, even run at WOT will not carbon up the port most of the time, but I have found alot that because of the baffles in the muffler, will carbon up the muffler. Trimmers, because of the EPA rules have a much smaller exhaust port then what was on models 10 years ago for the same CC size. Along with the sound restrictions just like the blowers create more back pressure and because of there smaller size port will carbon up the port and eventually the muffler. The only reason a spark arrester is in the muffler is to stop a spark from coming out and starting a fire.
Soooo unless you are in NW Georgia, you really don't need anything else clogging up the muffler and exhaust port. There just ain't nothing good on TV tonight
Masters Degree in Thinking Out Side Of The Box,Graduate of the MacGyver Institute of Ingenuity

The primary function of an Engineer is to make it difficult for the Fabricator and impossible for the Mechanic

RTFM What a concept

Reply With Quote
Old 10-09-2007, 04:58 PM
johnp900 johnp900 is offline
LawnSite Member
Join Date: May 2006
Posts: 71
Don't take them out. The spark arrestor is also the "check engine light" for a two cycle. Yes, if you take them out, then the carbon tends to build up at the exhaust ports, heat goes up & then the cylinder & piston trash. If the screen is carboning up excessively, then you have other issues that need to be addressed. A properly tuned & running engine just does not have carboning problems. Also, the screen is only about $1.50. That's pretty cheap insurance.
Reply With Quote
Old 10-09-2007, 07:07 PM
dutch1's Avatar
dutch1 dutch1 is online now
LawnSite Silver Member
Join Date: Dec 2004
Location: Jayhawk
Posts: 2,227
I hate to disagree, John, but I've serviced well over 500 Echo and Shindiawa 2 cycle products. I've seldom found an obstructed exhaust port on any product that had the screen removed. On the other hand I have found numerous pieces that had both carboned up screens AND exhaust ports. Restro is absolutely correct in his assessment. As the screen starts to build up with carbon there is no other place for it to go but into the muffler, exhaust port, ring(s) or piston dome. It never fails that the plug is well coated in carbon as well.

Blocked screens and ports are almost always the result of imcomplete combustion.. The biggest contributor is running at lower RPMs, the second is improperly mixed fuel(too rich) and the third is improper high and low speed adjustments in the case of an adjustable carb.

Reply With Quote
Old 10-09-2007, 08:47 PM
khouse khouse is offline
LawnSite Bronze Member
Join Date: Feb 2001
Location: lee's summit, mo
Posts: 1,476
Get that screen out and be done with it! Free flowing exhaust is king! Heck the way your detune a racing Briggs engine is with an exhaust restricter. That's what your screen will do - restrict your power. Pull it out - the world will still spin.
"If man can make it - man can break it"
Reply With Quote

Thread Tools
Display Modes

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

Forum Jump

Layout Style:

Powered by vBulletin® Version 3.8.6
Copyright ©2000 - 2016, Jelsoft Enterprises Ltd.
Copyright ©1998 - 2012, LawnSite.comô - Grand View Media
All times are GMT -4. The time now is 07:49 PM.

Page generated in 0.08225 seconds with 10 queries