Compression Improvement ++ Marvel Mystery Oil!
XS11 Folks,
Seems the Marvel "Mystery" Oil helped make some improvement in compression. I spun the motor a bit and installed the plugs. She smoked a little but not too much. Took 'er over to the gas station for a fill up and a little bit of a ride to get 'er warmed up. The trip total was about 6 miles @ 35mph to 45mph. I wound 'er out to 7k a couple times and returned to do a compression test.
Looking at the lower half of the chart you'll notice the improvement in compression in the gray box area with red arrow. The #4 cylinder stayed the same at 130#.
Everyone that commented about stuck rings was correct. Tonight, after the bike is completely cold I may try a couple more tablespoons of MMO and let her sit for another day or so. I don't really expect it to improve the compression on it's own every day but it may be breaking some crud loose from between or behind the rings and a little more couldn't hurt????
The compression numbers are all still very low according to the spec. given in the manual. However, I'd be pretty darn happy with 130 across the board. and wouldn't even consider pulling it apart. I still need to do a shim re-check and will do that after a longer ride (that's why it's blank in chart).
I will be able to take a real ride this weekend. The front end feels a little "funny" so I'm going to look that over real well before any longer trip.
I'll put some new Yama-Lube and a new filter in it before the ride. I'll report any compression improvement after the ride.
It's July now and the June "buying freeze" is over! I've got a ton of stuff headed my way. The FRONT brakes will be better when the new 16mm master arrives from MikesXS and the SS front Russell lines (3) arrive from Evil-Bay. I also have a set of saddle bag supports coming that should keep the soft bags out of the rear wheel on our way to XSSE.
Respectfully,
Kurt
XS11 Folks,
Seems the Marvel "Mystery" Oil helped make some improvement in compression. I spun the motor a bit and installed the plugs. She smoked a little but not too much. Took 'er over to the gas station for a fill up and a little bit of a ride to get 'er warmed up. The trip total was about 6 miles @ 35mph to 45mph. I wound 'er out to 7k a couple times and returned to do a compression test.
Looking at the lower half of the chart you'll notice the improvement in compression in the gray box area with red arrow. The #4 cylinder stayed the same at 130#.
Everyone that commented about stuck rings was correct. Tonight, after the bike is completely cold I may try a couple more tablespoons of MMO and let her sit for another day or so. I don't really expect it to improve the compression on it's own every day but it may be breaking some crud loose from between or behind the rings and a little more couldn't hurt????
The compression numbers are all still very low according to the spec. given in the manual. However, I'd be pretty darn happy with 130 across the board. and wouldn't even consider pulling it apart. I still need to do a shim re-check and will do that after a longer ride (that's why it's blank in chart).
I will be able to take a real ride this weekend. The front end feels a little "funny" so I'm going to look that over real well before any longer trip.
I'll put some new Yama-Lube and a new filter in it before the ride. I'll report any compression improvement after the ride.
It's July now and the June "buying freeze" is over! I've got a ton of stuff headed my way. The FRONT brakes will be better when the new 16mm master arrives from MikesXS and the SS front Russell lines (3) arrive from Evil-Bay. I also have a set of saddle bag supports coming that should keep the soft bags out of the rear wheel on our way to XSSE.
Respectfully,
Kurt
Comment