Does anyone have experience on what ec200 compression should be?

[mwinschel]

Can anyone submit real numbers on this? Anyone have a 200 that has done a rebuild on that can share their information? My new to me 200 has unknown hours racing (2011 raced for several seasons with no engine work done). My pre tear down compression on my meter was about 160, which did not seem too bad. Trying to see if there is a benchmark for rebuild? See the KTM 200s are in the 200 psi range, I dont know if that is a reasonable number for the EC200 or not. I know the 250 and 300 numbers are different. Even though it seemed decent I am going to do the piston and rings because of unknown hours, just trying to see if its possible to get something of a database from experience.

EDIT: Took engine apart tonight. End gap on current rings was greater than the max 0.63mm gauge that was in my set, so they were due.

 

[Mo.man]

Installed new std piston and rings when mine was at 150lbs then checked it and I had 185. Bike still ran good at 150 but had noticeably more power after new piston. Mine is a 2007

 

[barossi73]

id expect 180-190ps would be roughly what to expect.compression guages are notorious for variation.ie 2 different guages will often give two different readings.why not do the topend then do a compression test on your guage for a benchmark.or just commit to a topend every ? engine hours.
unless youve removed base gaskets or modified head in which case the compression test will be necessary.getting out of my depth now but i think 195ps is about absolute max on most pump fuels?someone more knowledgeable will hopefully chime in...

 

[(F5)]

Hate to even consider the testers a tool. A broad indication at best. You've done the right thing. Measure the gap.

The 200 in particular like to have the squish fixed. That means sending the head off to be machined to correct squish height and compensation for bowl to allow that correction.

 

[thejackrabbit]

my 2006 200 had 165-170 with 1.6mm of squish with a unmodified head

 

[Jakobi]

Agree with those above. When you're working with such little compression volume the configuration of a particular gauge can have a massive influence on the outputted result.

For instance, my 250's engines have been setup with squish at 1.25mm. One runs 14:1 UCCR. The other I had machined to 13:1 UCCR to try and increase some top end and overrev.

My particular comp gauge uses an adapter (adds volume). I haven't checked where to see if it also includes the volume of the pipe up to the gauge either. For the higher comp setup I will only blow around 150psi on a freshly broken in engine. On the lower comp I get 140-145psi. I use this to monitor losses, but even then there are a lot of variables to consider - atmospheric changes, how hard you kick, etc.

Ring ends on the other hand never lie. No real substitute for measuring them.

Speaking of which, I measured my lower comp setup recently. Has dropped around 20psi (approx. 15%). Still starts easy enough, and runs like beast in the top end but has lost its off idle and mid range snap. Approx 65hrs. Time for a new slug!