- Joined
- Feb 10, 2013
- Messages
- 18
Hi all,
After years of thinking about it, I've finally gone ahead and gotten myself a Commando! Wow, does that ever scratch an itch. I've been wanting one since I was a kid. I have a long history with British cars from the 60's and with brass and nickle cars, so I don't come into this blind, but I'm certainly not up to speed on classic bikes. This is going to be fun!
So, some background: When I went to look at it, the gentleman couldn't get her to fire up, which I was sure was attributed to bad gas clogging the carbs and petcocks. I could tell it had been sitting longer than he wanted to admit. It's a '73 850 with a 75 (I believe) front end on it. Not sure how (or why) that happened but I suspect the originals were damaged at some point. The numbers don't match, and the paint isn't great, but I'm not looking for a concours correct original - I just want to ride it. For other mods (as far as I can see) it's got a Mikuni and a Boyer ignition. I got a great deal on the bike because of the lack of seeing it chooch, dragged her home, and set about getting everything cleaned up.
I broke the carb down and cleaned it out with the ultrasonic cleaner and a bucket of elbow grease. It was in need, for sure, but wasn't too terrible. The petcocks, on the other hand, were disgusting. Once those were clean, I filled the tank with some tumbler media and detergent from my vibratory polisher, and shook the tar out of it for about an hour. After a thorough rinse, I used the POR fuel tank kit to seal everything up. Once it cured for five days, I popped in a new battery, new gas, and started kicking. I got her running on the third or forth, which I take as a victory for a kick-start newb. I got the idle set at about 1000 rpm and it ticks over pretty steady. Brakes, clutch, trans, lights, and charging all seem to work okay, so I took her out for her maiden-to-me voyage.
Overall, it seems to run pretty well. The brakes are certainly nothing to write home about, but I think they can be improved with some tinkering. The clutch is a tough one, but again, I think a new cable will go a long way towards helping that out. I believe I overfilled the oil tank and, as a result, I have a very well lubricated right shoe, but that's no biggie. The only real issue I have is that when the bike is nice and hot it starts to miss really badly. At first, it was just low down in the revs (~1/4 throttle), so I was tinkering with the air screw trying to find a happy spot but then it started acting very poorly no matter what RPM I was at.
I'm leaning towards it being an ignition problem since it gets much worse with heat, but logic says I should look at the last thing I worked on, which was the fuel system. I'm relatively sure I did a good job rebuilding it, but again, I always doubt my last job. Maybe the experts here can point out something obvious with the setup on the Mikuni.
Needle - 6DH3 on the middle ring
Slide - 2.5
Main Jet - 250
Pilot - 35
Cutaway - 2.5
Needle Jet - 159
Air screw - I started with it at two revolutions out and tinkered from there.
Anyway, I'm extremely happy to add this to my stable of misfit vehicles and look forwards to many many years of tinkering with it.
Cheers all!
After years of thinking about it, I've finally gone ahead and gotten myself a Commando! Wow, does that ever scratch an itch. I've been wanting one since I was a kid. I have a long history with British cars from the 60's and with brass and nickle cars, so I don't come into this blind, but I'm certainly not up to speed on classic bikes. This is going to be fun!
So, some background: When I went to look at it, the gentleman couldn't get her to fire up, which I was sure was attributed to bad gas clogging the carbs and petcocks. I could tell it had been sitting longer than he wanted to admit. It's a '73 850 with a 75 (I believe) front end on it. Not sure how (or why) that happened but I suspect the originals were damaged at some point. The numbers don't match, and the paint isn't great, but I'm not looking for a concours correct original - I just want to ride it. For other mods (as far as I can see) it's got a Mikuni and a Boyer ignition. I got a great deal on the bike because of the lack of seeing it chooch, dragged her home, and set about getting everything cleaned up.
I broke the carb down and cleaned it out with the ultrasonic cleaner and a bucket of elbow grease. It was in need, for sure, but wasn't too terrible. The petcocks, on the other hand, were disgusting. Once those were clean, I filled the tank with some tumbler media and detergent from my vibratory polisher, and shook the tar out of it for about an hour. After a thorough rinse, I used the POR fuel tank kit to seal everything up. Once it cured for five days, I popped in a new battery, new gas, and started kicking. I got her running on the third or forth, which I take as a victory for a kick-start newb. I got the idle set at about 1000 rpm and it ticks over pretty steady. Brakes, clutch, trans, lights, and charging all seem to work okay, so I took her out for her maiden-to-me voyage.
Overall, it seems to run pretty well. The brakes are certainly nothing to write home about, but I think they can be improved with some tinkering. The clutch is a tough one, but again, I think a new cable will go a long way towards helping that out. I believe I overfilled the oil tank and, as a result, I have a very well lubricated right shoe, but that's no biggie. The only real issue I have is that when the bike is nice and hot it starts to miss really badly. At first, it was just low down in the revs (~1/4 throttle), so I was tinkering with the air screw trying to find a happy spot but then it started acting very poorly no matter what RPM I was at.
I'm leaning towards it being an ignition problem since it gets much worse with heat, but logic says I should look at the last thing I worked on, which was the fuel system. I'm relatively sure I did a good job rebuilding it, but again, I always doubt my last job. Maybe the experts here can point out something obvious with the setup on the Mikuni.
Needle - 6DH3 on the middle ring
Slide - 2.5
Main Jet - 250
Pilot - 35
Cutaway - 2.5
Needle Jet - 159
Air screw - I started with it at two revolutions out and tinkered from there.
Anyway, I'm extremely happy to add this to my stable of misfit vehicles and look forwards to many many years of tinkering with it.
Cheers all!