Searched about, couldn't find a thread that answered all my questions. Sadly, my latest aquisition- the Mongrel, as he's come to be known- seized the motor on the interstate on the way back from motorcycle club coffee. 
The mongrel was built from parts and never finished by a guy that died, and then my friend bought it from his estate, and then I got it, and then it sat for a while and on and on and on... so it's a february 1970 triumph t120r motor in a tr6c frame, and it's got a steve mcqueen desert sled vibe going. Nothing is original or stock or makes any sense, but the motor seems to be straight forward 1970. Slapped in a tri-spark and gave the amals a dunk in the ultrasonic and she fired right up. Timed it with a light, then checked the color on the pluggies (nice carmel color) and away we went. Ran great for about 40 miles, then the drive side piston seized. It let go and kept running on one pot, but the damage was done. Was probably quite a sight going down main street with a huge blue plume of smoke behind it for a few miles as I limped er home.
Anyhoo, started stripping it down and the motor oil looked blacker than any diesel I ever changed back in the day despite having only 40 miles on it. I guess that the modern detergent oil went to work breaking down the sludge in the probably jam packed trap and pumping it through the motor. Piston has an almost identical pattern of scuffing/scraping to the one from my Norton when the motor seized up due to oiling issues from a plugged sludge trap. Same side too. Bummer man.
Got on F/G and bought the usual stuff, pistons that were in it were already .020 over so I got .040s with rings and pins, bought new valves cause the tips were all cratered, bought new mains and a tranny rebuild kit, gaskets ect., now that I'm impoverished I figured, hey, lets get some more crap. Hence the title and the actual question- Should I get new MAP/Hepolite steel rods while I'm in there ($500! Ouch!) or just leave well enough alone and keep the stock alloy rods. Second question- do I need to rebalance the crank for the new rods? My sincerest hope is that when I mike the journals they're good with a fresh set of shells and don't need a regrind. Montana is a long way away from any reputable 1960's motorcycle crank grinders.... If I do have to send it down to mile high, I'll do rods and undersize bearings and balance anyway, but if not... Do I really need to rebalance? I couldn't find any weights for stock vs MAP rods. I'd have it miked, but this is my first triumph, so of course I need all new specialty tools to get in there. They're in the mail.
Vibration won't be too much of a concern as this bike will be doing mostly desert sled type stuff, but I would like to ocasionally ride it to work and what not, and that's about 15 miles of freeway. Ok.... FLAMEWAR BEGIN!
The mongrel was built from parts and never finished by a guy that died, and then my friend bought it from his estate, and then I got it, and then it sat for a while and on and on and on... so it's a february 1970 triumph t120r motor in a tr6c frame, and it's got a steve mcqueen desert sled vibe going. Nothing is original or stock or makes any sense, but the motor seems to be straight forward 1970. Slapped in a tri-spark and gave the amals a dunk in the ultrasonic and she fired right up. Timed it with a light, then checked the color on the pluggies (nice carmel color) and away we went. Ran great for about 40 miles, then the drive side piston seized. It let go and kept running on one pot, but the damage was done. Was probably quite a sight going down main street with a huge blue plume of smoke behind it for a few miles as I limped er home.Anyhoo, started stripping it down and the motor oil looked blacker than any diesel I ever changed back in the day despite having only 40 miles on it. I guess that the modern detergent oil went to work breaking down the sludge in the probably jam packed trap and pumping it through the motor. Piston has an almost identical pattern of scuffing/scraping to the one from my Norton when the motor seized up due to oiling issues from a plugged sludge trap. Same side too. Bummer man.
Got on F/G and bought the usual stuff, pistons that were in it were already .020 over so I got .040s with rings and pins, bought new valves cause the tips were all cratered, bought new mains and a tranny rebuild kit, gaskets ect., now that I'm impoverished I figured, hey, lets get some more crap. Hence the title and the actual question- Should I get new MAP/Hepolite steel rods while I'm in there ($500! Ouch!) or just leave well enough alone and keep the stock alloy rods. Second question- do I need to rebalance the crank for the new rods? My sincerest hope is that when I mike the journals they're good with a fresh set of shells and don't need a regrind. Montana is a long way away from any reputable 1960's motorcycle crank grinders.... If I do have to send it down to mile high, I'll do rods and undersize bearings and balance anyway, but if not... Do I really need to rebalance? I couldn't find any weights for stock vs MAP rods. I'd have it miked, but this is my first triumph, so of course I need all new specialty tools to get in there. They're in the mail.
Vibration won't be too much of a concern as this bike will be doing mostly desert sled type stuff, but I would like to ocasionally ride it to work and what not, and that's about 15 miles of freeway. Ok.... FLAMEWAR BEGIN!
