UK Monster Owners Club Forum » .: Technical :. » Engines, Clutch, Gears » High comp pistons in a M900 ?

Reply
 
Thread Tools Display Modes
Old 24-11-2019, 11:08 AM   #1
the lodger
Registered User
 
the lodger's Avatar
 
Join Date: Oct 2019
Location: Chorley
Bike: M900
Posts: 160
High comp pistons in a M900 ?

I have the possibility of fitting high comp pistons and rings in my M900. Apparently the cost is less than the cost of OEM Ducati rings only so a bit of a no brainer. However I would like to be reassured that if I go down this route then the bike will still be nice to ride

I am no racer, so extra power for its own sake is not a high priority, just a nice to have. So has anyone fitted high comp pistons and what was the effect? Many thanks
__________________
Contents may settle !
the lodger is offline   Reply With Quote
Old 24-11-2019, 11:16 AM   #2
Darkness
.
 
Darkness's Avatar
 
Join Date: May 2007
Location: Stockbridge
Bike: M900
Posts: 1,984
Make sure your starter motor and its cable and earths are in perfect condition!
__________________
Original and Best since 1993
Darkness is offline   Reply With Quote
Old 24-11-2019, 11:38 AM   #3
Darren69
Transmaniacon MOC
 
Darren69's Avatar
 
Join Date: Sep 2013
Location: Sutton In Ashfield
Bike: Multiple Monsters
Posts: 6,011
If the cost makes it a no brainer go for it. Upping the compression should give you a bit more mid range torque not increasing overall power as much. Have you been considered a bigger bore kit 944 if you are going to the expense of hi comp with the 904 you might as well put more cc in there and the 900ss stuff is bolt on.
Darren69 is offline   Reply With Quote
Old 24-11-2019, 11:39 AM   #4
Saint aka ML
Junior ah to be young
 
Saint aka ML's Avatar
 
Join Date: Nov 2007
Location: London
Bike: Multiple Monsters
Posts: 2,058
The starting motor comment is valid for early carbed m900 when they went IE they also changed gearing on starter motor.
However nice clean earth is good idea either way.

There is no real side effects to off the shelf HC pistons.
Whom ever fits them should adjust timing (retard it), adjust fuelling a bit and off you go. If you can fit adjustable belt pulleys and get them to dial in cams. All is cheap and slippery slop to modding hehe.

It will run bit hotter so at 30c stuck in traffic you will feel it. Nothing to worry about.
You will have more low and mid torque, if you do fuelling on dyno you could get 2-3 bhp.
Main benefit is torque and with correct timing throttle response.
__________________

"I am Lucazade"
Saint aka ML is offline   Reply With Quote
Old 24-11-2019, 11:56 AM   #5
Saint aka ML
Junior ah to be young
 
Saint aka ML's Avatar
 
Join Date: Nov 2007
Location: London
Bike: Multiple Monsters
Posts: 2,058
Quote:
Originally Posted by Darren69 View Post
If the cost makes it a no brainer go for it. Upping the compression should give you a bit more mid range torque not increasing overall power as much. Have you been considered a bigger bore kit 944 if you are going to the expense of hi comp with the 904 you might as well put more cc in there and the 900ss stuff is bolt on.
900ss was also 900cc so if you going 944 you will need to bore cylinders. Not hard job so ok on cost but then you need to do proper fuelling and better pipes if not present.
__________________

"I am Lucazade"
Saint aka ML is offline   Reply With Quote
Old 24-11-2019, 02:18 PM   #6
Yorkie
Anglo-Saxon Warrior
 
Yorkie's Avatar
 
Join Date: Aug 2002
Location: North Yorkshire
Bike: M900
Posts: 2,485
I have dropped in JE Hi-Comp pistons to both my 900SS powered Monster and its replacement ST2 944 engine with no issues.

Open cans, or even a spaghetti style system, and a performance air filter all dialled in on a dyno would be best.

Yorkie
__________________
NO ICE, GUN IT!
Yorkie is offline   Reply With Quote
Old 27-11-2019, 09:36 AM   #7
Dukedesmo
Registered User
 
Dukedesmo's Avatar
 
Join Date: Sep 2010
Location: Leics
Bike: M900
Posts: 2,828
High comp definitely an improvement with, IMO no downsides.

A word of warning though, be careful that supplied rings are compatible with Nikasil bores (chrome rings eat away the coating).

I have JE high comp (944cc) pistons in mine and have had a battle with bore wear, I think I've won said battle now but only after a couple of replates & new rings...
__________________
M900, 916, LeMans II.

Dukedesmo is online now   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 On

Forum Jump


All times are GMT. The time now is 09:32 AM.

vBulletin Skins by vBmode.com. Powered by vBulletin® Version 3.8.3
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.