GasGas Riders Club Forum  

Go Back   GasGas Riders Club Forum > GasGas Enduro Technical Forums > Enduro Engine - 2 stroke

Enduro Engine - 2 stroke Cylinder, Piston, Tranny, Bearings, Clutch, Pipes & Silencers, etc.


Reply
 
Thread Tools Display Modes
  #1  
Old 03-07-2019, 09:15 PM
Skullanova Skullanova is online now
Member
 
Join Date: Apr 2018
Posts: 4
Default Top end questions

Hey guys first post so go easy on me please. Doing my first top end on a 09 ec250. Seems to run ok but kinda want to start from scratch with hours on the top end and it?s cold so good time to tinker. So I have Pulled the cylinder and cleaned her all up than scotchbrite on the cylinder walls but I can feel a lip up near the top. First off is it possible to get a shop to hone the cylinder with a diamond hone and will that work with the Nikasil coating that is currently on it? My second question is does anybody know the clearence tolerance between piston and cylinder if I install a Forged pistons vs a cast on or does it matter? Manual states .055mm to .1mm clearence I believe if I have her right. Or should I just slap a C piston (66.35) in it and not worry about the barely discernible ridge as the rest of the cylinder looks good with crosshatching and feels smooth?


Reply With Quote


  #2  
Old 03-08-2019, 12:29 AM
shawbagga's Avatar
shawbagga shawbagga is offline
Senior Member
 
Join Date: Feb 2012
Location: West Straya
Posts: 113
Default

C size & send it is what I'd do.
How many hours on cylinder?
__________________
'18 Gasgas XC250
Reply With Quote
  #3  
Old 03-09-2019, 10:20 PM
Skullanova Skullanova is online now
Member
 
Join Date: Apr 2018
Posts: 4
Default

Thanks shawbagga, that?s exactly what I think I will do than. As far as hours,no clue but I believe lots.
Reply With Quote
  #4  
Old 03-10-2019, 07:16 AM
Zman's Avatar
Zman Zman is offline
Platinum Level Site Supporter
 
Join Date: Apr 2010
Location: Burbs of Chicago
Posts: 1,410
Default

You can run it this way but make sure you use the same thickness base gasket or slightly thicker. You do not want the new piston and ring running into the cylinder ridge.

A diamond hone used to finish size the plating will also remove the ridge and true the cylinder but you will need the larger piston.

Just to confirm, is the original piston and cylinder sized for a B piston?
Reply With Quote
  #5  
Old 03-11-2019, 10:59 PM
Skullanova Skullanova is online now
Member
 
Join Date: Apr 2018
Posts: 4
Lightbulb

Yes Zman, the piston jug is marked b and the piston I removed was a b piston as well. Thanks for the reply, I just was not sure if I could get the cylinder diamond honed and keep the nichsel coating so thanks. Also it makes sense to throw a bigger or thicker gasket on the base of the jug in order to keep the new piston rings from contacting the ridge at the top of jug. Honestly I did not even think of doing that so thanks again man.
Reply With Quote
  #6  
Old 03-12-2019, 02:33 AM
Anders's Avatar
Anders Anders is offline
Gold Level Site Supporter
 
Join Date: Nov 2009
Location: Kongsberg, Norway
Posts: 704
Default

Quote:
Originally Posted by Skullanova View Post
...
Also it makes sense to throw a bigger or thicker gasket on the base of the jug in order to keep the new piston rings from contacting the ridge at the top of jug. Honestly I did not even think of doing that so thanks again man.
The downside of a thicker base gasket is that your squish band will be higher than before. Most of these engines have too big squish clearence. Do you know if the head has been reworked to reduce the squish?
__________________
Anders

"So you know, that you're over the hill when your mind makes a promise that your body can't fill" (Little Feat: Old Folks Boogie)

2015 EC200 Racing: TE bars, Rekluse Core Exp 3.0, 38mm Lectron & Ohlins S3 steering damper
2006 EC200: 2011 plastics, Rekluse Z-Start, revalved KYB forks & Scotts steering damper
1998 Bimota Supermono
1986 Duc Mille S2
1975 Guzzi sidecar hack
1961 Morini Corsaro 125
etc
Reply With Quote
  #7  
Old 03-12-2019, 07:28 AM
Zman's Avatar
Zman Zman is offline
Platinum Level Site Supporter
 
Join Date: Apr 2010
Location: Burbs of Chicago
Posts: 1,410
Default

Quote:
Originally Posted by Anders View Post
The downside of a thicker base gasket is that your squish band will be higher than before. Most of these engines have too big squish clearence. Do you know if the head has been reworked to reduce the squish?
I agree that going with a significantly larger base gasket will be a problem as well.
Reply With Quote
  #8  
Old 03-14-2019, 09:03 PM
Skullanova Skullanova is online now
Member
 
Join Date: Apr 2018
Posts: 4
Default

Thanks for the info guys. So if I understand correctly, I can get the cylinder honed by a shop with a diamond hone to remove the lip at top of the cylinder provided I have enough plating left todo this correct? Or do I need to get the cylinder re coated and than get her diamond honed at which point I may as well go with an A piston size? Much appreciated guys, thanks!
Reply With Quote
  #9  
Old 03-14-2019, 11:55 PM
(F5)'s Avatar
(F5) (F5) is offline
Gold Level Site Supporter
 
Join Date: Jul 2006
Location: Wellington New Zealand
Posts: 1,226
Default

A machine shop that deals with plated cylinders can hone it. Check first. They will tell you if it needs replating.
__________________
'07 EC300
496 CPI Cheetah RZ/RGV hybrid
675 Street Triple R
RS125 framed MB100 racer
Stinger T125 Suzuki
Reply With Quote
  #10  
Old 03-17-2019, 09:38 AM
Zman's Avatar
Zman Zman is offline
Platinum Level Site Supporter
 
Join Date: Apr 2010
Location: Burbs of Chicago
Posts: 1,410
Default

Quote:
Originally Posted by Skullanova View Post
Thanks for the info guys. So if I understand correctly, I can get the cylinder honed by a shop with a diamond hone to remove the lip at top of the cylinder provided I have enough plating left todo this correct?
Yes that is correct.

If the cylinder is worn too much they may tell you to replate it.
Reply With Quote
Reply



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


Similar Threads
Thread Thread Starter Forum Replies Last Post
Questions about my new xc-e john r b Enduro Electrical & Wiring 14 01-19-2014 02:22 PM
May Be Getting a GG But I Have Some Questions York Racing General Discussions & Announcements 6 12-02-2011 09:34 AM
Questions and help please? darrenrd General Discussions & Announcements 4 08-01-2011 11:24 PM
AC and DC Questions speedy08 Enduro Electrical & Wiring 2 05-07-2011 10:34 AM
Questions About The 07's Boomhauer General Discussions & Announcements 4 04-07-2007 12:17 PM




All times are GMT -5. The time now is 12:19 PM.


Powered by vBulletin® Version 3.8.6
Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.
Copyright 2009 - GasGasRider.org