Re: 1986 Suzuki DT40 Compression
did you warm up the eng before you tested?..... did you put any oil into the cyls before you tested?........ did you remove all the plugs so the eng could trun freely?....did you try any other comp gauges?...... those are some of the variations and question that could be asked if you had low or drastically different comp #s............ you dont really have to answer those questions it was just an example........ i believe thats what jb was meaning when he said " tested with your gauge under your conditions and using your technique"
you will find most comp gauges will not read the same on the same eng....... even the more expensive ones arent as accurate as we would all hope.....
your comp needs to be within 10% of each other for it to perform correctly: if you have 100 on one and 80 on another that would be a 20% difference and you would have performance issues.
being at 120 you could have as much as 12-15# difference before you really have performance problems.
im sorry i dont know what the factory specs are on your eng... but 120 sounds good and strong.... maybe well kept or low hours.
i hope that cleared it up a little.
