High Quality Chainsaw Bars Husqvarna Toys

Epoxy in the intake? Ms660

Golddredger

Well-Known OPE Member
Local time
10:36 PM
User ID
5385
Joined
Feb 18, 2018
Messages
13
Reaction score
28
Location
Paradise, Ca.
Hey fellas,
Keeping seeing in the 660 build threads guys saying they have epoxied the intake. I looked through cant really find any good pictures of this and or why its being done? Can you guys post some pictures and explain why you are doing it? Thanks!
 

huskihl

Muh fingers look really big
GoldMember
Local time
1:36 AM
User ID
360
Joined
Dec 31, 2015
Messages
22,456
Reaction score
143,008
Location
East Jordan, MI
Country flag
MS660's are known to have too much exhaust duration. They seem to run better with the exhaust opening down around 100° after tdc. Stock, they vary from about 93 to 98°. In order to get the exhaust port physically lower, the base gets cut on a lathe. This also makes the intake lower. Sometimes too low for good performance. Many consider an 80° intake opening to be about right, but most of the Farmertec cylinders have the intake down around 86. After machining, they get close to 89°, which isn't optimal. Filling the bottom of the intake port with epoxy allows you to grind it down to a more preferred opening height
 

Deets066

AKA Deetsey
Local time
1:36 AM
User ID
290
Joined
Dec 28, 2015
Messages
15,435
Reaction score
73,471
Location
Illinois
Country flag
Awesome! Pictures are worth a thousand words. Thats the visual I had in mind with huskihl description. Now with pictures I am on board 100%.
Port prep is big, definitely wash and degrease cylinder. I like to grind in a few dimples on the floor. Then bead blast
 

SixGun

Super OPE Member
Local time
1:36 AM
User ID
440
Joined
Jan 8, 2016
Messages
280
Reaction score
481
Location
Hackettstown NJ
Country flag
Cool, thanks ! I heard some guys were using aluminum reinforced stuff.
Doing a couple 660's now and they will need it. Pushing 85* before cutting base.
 

huskihl

Muh fingers look really big
GoldMember
Local time
1:36 AM
User ID
360
Joined
Dec 31, 2015
Messages
22,456
Reaction score
143,008
Location
East Jordan, MI
Country flag
Cool, thanks ! I heard some guys were using aluminum reinforced stuff.
Doing a couple 660's now and they will need it. Pushing 85* before cutting base.
Yeah there's fancy stuff out there if you want to pay for it. I've never had jb fail in an intake if the surface is clean with a burr finish. If it did fail, it turns to a soft powder and I don't believe it would cause damage
 

SixGun

Super OPE Member
Local time
1:36 AM
User ID
440
Joined
Jan 8, 2016
Messages
280
Reaction score
481
Location
Hackettstown NJ
Country flag
Thanks for great info guys. I've been out of the saw game for a bit and never did a full port job on a 660, I usually just did the basics DP Muff, Ign advance, pull limiters.
 

farminkarman

I like the red & black ones
GoldMember
Local time
12:36 AM
User ID
13535
Joined
Aug 17, 2020
Messages
3,620
Reaction score
20,402
Location
Neenah Wisconsin
Country flag
Question for you guys....when you are prepping for the epoxy, do spray some kind of oil on the piston so the epoxy doesn't stick to it?
 

Mastermind

Chief Cat Herder
Staff member
GoldMember
Local time
12:36 AM
User ID
4
Joined
Dec 3, 2015
Messages
47,633
Reaction score
308,457
Location
Banner Springs Tennessee
Country flag
Question for you guys....when you are prepping for the epoxy, do spray some kind of oil on the piston so the epoxy doesn't stick to it?

After I degrease the jug, I use masking tape to cover the port. Then fill with epoxy.
 

farminkarman

I like the red & black ones
GoldMember
Local time
12:36 AM
User ID
13535
Joined
Aug 17, 2020
Messages
3,620
Reaction score
20,402
Location
Neenah Wisconsin
Country flag
I haven't really found gains on filling the intake on an oem 660 jug.....the 661 I have though.
It looks like I'm going to be doing another 359. The last one I did, I elected to not do machine work on it because the intake was already at 80. I'd like to cut the squish on this next one, but I want to keep the intake up at 80...maybe even a little higher. Was wanting to understand best practice for doing the whole epoxy thing.
 
Top