2000 RM 265 compression?

C

ckassen

Member
Jun 26, 2007
85
0
I just recieved my top end back from eric gorr who recently ported and bored my cylinder. I have started the bike up and was wondering what the compression should be? I heard 180-210 on a fresh motor...

One other thing, the compression, there are only 2 places I could be losing it, correct. Either through the head or through the rings, correct?

One other thing, what jets should I be running? (If anybody happens to have this kit)

2000RM250
All stock except porting/bore
 
C

ckassen

Member
Jun 26, 2007
85
0
I have been doing some testing and have the PSI at 150 while the engine is cold....Eric said that the engine should be inbetween 180-210 psi....Does anybody know how much the psi would increase when the engine is warm?
Thanks,
Chris
 
C

ckassen

Member
Jun 26, 2007
85
0
Allright, thanks.

The reason that I havent warmed it up is because I have a cracked clutch cover and it leaks slightly...Would running the bike with this crack cause the engine to run wierd? I have heard that the crankcase/tranny have to be pressurized...?
 
G

griffbones

Member
Sep 12, 2006
329
1
If this is a fresh motor, you will need to heat cycle it a few times and let it break in before you can get a true compression reading. If you have only started it once the rings aren't even seated yet.
 
whenfoxforks-ruled

whenfoxforks-ruled

Old MX Racer
~SPONSOR~
Oct 19, 2006
8,129
2
Merrillville,Indiana
And be careful with that bike! That is one of the few suzuki's I have enjoyed. The forks are the closest to a set of full on race forks, even today! They are extremely thin and do not like crashing. The motor rips once you get the exhaust valve tension set.
 
B

BigRedAF

Member
Jan 9, 2005
739
0
ckassen

It seems weird to me that you would be asking any of us what your compression should be and what jets to run. If Eric built that engine as you say then simply ask the man him self. He's only a phone call away.

Compression tests should be done on a warm engine. Hold the throttle WFO while kicking until the pressure stops rising. 180-210 would be a good number.

If your center case is cracked you would have a problem. The clutch cover is only going to cause an oil leak.
 
C

ckassen

Member
Jun 26, 2007
85
0
I ran it again and let it warm up and the compression is at 130psi, that is what I started at....How much time until the motor starts building? I have ran it for say 30-45min, low rpm.....
 
C

ckassen

Member
Jun 26, 2007
85
0
Well I found one problem...I had a friend help me put the bike together and I had him tighten the bolt that holds the bracket for the powervalve(exhaust valve), the bolt was loose enough that the bracket had slid out of place(inbetween the 2 springs)...If you want something done right do it yourself.....but that wouldnt have anything to do with the compression would it?

One other thing, when would the powervalve move? I kicked the bike over and the powervalve didnt even move....
 
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BigRedAF

Member
Jan 9, 2005
739
0
If the power valve is open it will act as if your exhaust port is higher and you will have less compression. As far as movement goes, It will open at mid and up RPM's. It stays closed at low RPM's to lower exhaust port height and increase torque. It opens as you build RPM's to allow for more RPM on the big end.

It would be nice if you could check your compression with an other gauge before you tear the top end down again. I've seen them fail more than once and I've used Snap On for the last 32 years.
 
C

ckassen

Member
Jun 26, 2007
85
0
On the intake side of the piston(where the 2 holes-horizontal to each other-are), there is wear....The cylinder seems to be ok, but I dont understand why this side of the piston is worn. everything els seems ok.....
 
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BigRedAF

Member
Jan 9, 2005
739
0
Did you clean the cylinder before you put the top end together? If it was bored and ported then it would have trash in it...

Also you should put a light coat of pre mix oil on the piston, rings and top end bearing with your finger when you assemble the engine.
 
IndyMX

IndyMX

Crash Test Dummy
~SPONSOR~
Jul 18, 2006
5,548
2
Amo, IN
ckassen said:
On the intake side of the piston(where the 2 holes-horizontal to each other-are), there is wear....The cylinder seems to be ok, but I dont understand why this side of the piston is worn. everything els seems ok.....
Click to expand...


Sounds stupid, but what side of the cylinder do you have the ring gap pointed?
 
C

ckassen

Member
Jun 26, 2007
85
0
I am simply wondering what could be wrong. The rings were in there correct locations, and everything seemes ok....The ring end gap is .012in....The intake side of the piston is scared...The rings are in good condition....The cylinder looks good, there are some dark marks on the cylinder walls, but it seems smooth..?
 
whenfoxforks-ruled

whenfoxforks-ruled

Old MX Racer
~SPONSOR~
Oct 19, 2006
8,129
2
Merrillville,Indiana
As I remember the intake side has some long intake bridges. You could verify. If it does you could be looking at a cold seizure. I will have to dig up the information on preloading that exhaust spring. The more tension the better the midrange hit. It is fairly sensitive once you get to the sweetspot, like 2 turns. What kind of plug are you using for the bike, as I remember that model has an outrageous priced plug!
 
C

ckassen

Member
Jun 26, 2007
85
0
Yes it does have long intake bridges...I will check the plug # when I get home....I know it has a 8 in it.....maybe __8ek?
 

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