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ok.. i have a 72 Cb175.. it was running, sort of, last week. when i could get it running, it idled at 3k, spec is 1.2k if what i read was correct.
when you go to give it gas, it would only go to 5k and it would bog down, often stalling when you release the throttle. took it out in front of my house and when in gear it had no power, it was almost like i was just riding at idle speed no matter how i twisted the throttle.
ive cleaned the carbs about 5 times now, they're both nice and clean, tho the main jet needles like to wiggle themselves loose and fall into the bowl, i usually notice it has happened when i see that side spraying gas droplets instead of exhaust, out the muffler.
ive checked the throttle cable, and it does like to stick but for the most part it moves freely, and retracts the cable nicely when i release it.
new plugs, but havent had a chance to use them yet.
i figured the reason it wasnt revving was a compression issue, i dont have a tester, but i assumed on a bike this old, and given the condition i got it, that the gaskets were probably shot.
tore apart the top end, and surprisingly, the gaskets up top were great, looked like they had already been replaced.
found 3 nuts just sitting in the bottom of the motor, no idea where they came from. but they didnt look chewed up, so hopefully they didnt damage anything.
along with the nuts, i found 2 of the 4 screw looking things that attach to the valves (i think), they were also just sitting there, i put them back on where i saw a 3rd identical screw located, but the 4th, is bye bye.
moved on to the lower end, and as i thought, these gaskets were comepletely shot.
got some gasket paper and goop, and re-did both sides, and the little gasket for the cover of the stator (i think), it was on the left lower side of the motor.
almost had it comepletely re-assembled when i remembered that the motor had rotated a bit, and the camshaft/ sprocket had also rotated, so i tore the top back apart to reset the timing. found a pdf of the manual(which is also linked on this site as well), and saw i had to set the notch on the stator, to a notch or line next it in the housing. (ill take some pics later and upload em, but im hoping you guys can translate my noob-speak lol).
now, the stator itself has 2 sets of lines. one set has "FT" right under them, the other has nothing.
i first set the 2 lines with "FT" to the notch in the housing, the pistons themselves appeared to be at the top of their rotation. and according the manual, i had to set the cam sprocket so the little "O" was at the top as well. slapped it all back together, hand cranked the motor to make sure everything moved nicely, then bolted the head and covers on. went to hand crank again, and it would not move, at all. tried the starter, just to see if that would do it, it didnt.
so i took the cylinder cover off, and it started moving again. not sure what that was all about, but it moves freely now when bolted.
i checked the valves, they were jiggling and very loose, and if i was correct in the screw i was supposed to tighten them with (the loose screws that i had found in the motor), and i hand tightend them til i couldnt wiggle em anymore, then backed em off a hair so i could just barely move em with my hand. (no gapper to check with, so im guesing here)
cranked the motor to test, and it all moved nicely. so i put the plugs in, couple drops of gas in the carb and tried starting it, and it ran. it idled high like before, but it sounded alot smoother than before, so i shut it off, re-attached the gas tank, filled it about a quarter full, set the carbs to stock (fuel out 3 full turns from fully closed, and air 1 and a quarter out from full closed), went to start it and as soon as the plugs fired, it clanked horribly loud and stopped the starter. i hit the button again, and it turned over great, but as soon as it sparks it clanks and stops.
loosened the plugs, thinking they were hitting and that wasnt it. turned it over with the boots to the plugs disconnected, and it turned over great, no clank, no nothing. reconnected, and instant clank.
i cant kickstart it at the moment, because the spindle that the kick lever bolts to, is stripped. i can use vice grips to very slowly, and carefully hand crank it, but starting is out of question.
according to what i have read, it may possibly be a timing issue, essentially, the spark it firing at the wrong time, (the upstroke of the piston), and pretty much stopping it dead in its tracks. also, it may be firing on the wrong rotation of the cycle (exhaust/ intake).
i dont know what im doing here, im just blindly trying stuff, and researching the web to find answers, but ive done all i can without some help from some1 who actually understands this stuff.
thank you so much for the help, and im totally sorry about this massive post
when you go to give it gas, it would only go to 5k and it would bog down, often stalling when you release the throttle. took it out in front of my house and when in gear it had no power, it was almost like i was just riding at idle speed no matter how i twisted the throttle.
ive cleaned the carbs about 5 times now, they're both nice and clean, tho the main jet needles like to wiggle themselves loose and fall into the bowl, i usually notice it has happened when i see that side spraying gas droplets instead of exhaust, out the muffler.
ive checked the throttle cable, and it does like to stick but for the most part it moves freely, and retracts the cable nicely when i release it.
new plugs, but havent had a chance to use them yet.
i figured the reason it wasnt revving was a compression issue, i dont have a tester, but i assumed on a bike this old, and given the condition i got it, that the gaskets were probably shot.
tore apart the top end, and surprisingly, the gaskets up top were great, looked like they had already been replaced.
found 3 nuts just sitting in the bottom of the motor, no idea where they came from. but they didnt look chewed up, so hopefully they didnt damage anything.
along with the nuts, i found 2 of the 4 screw looking things that attach to the valves (i think), they were also just sitting there, i put them back on where i saw a 3rd identical screw located, but the 4th, is bye bye.
moved on to the lower end, and as i thought, these gaskets were comepletely shot.
got some gasket paper and goop, and re-did both sides, and the little gasket for the cover of the stator (i think), it was on the left lower side of the motor.
almost had it comepletely re-assembled when i remembered that the motor had rotated a bit, and the camshaft/ sprocket had also rotated, so i tore the top back apart to reset the timing. found a pdf of the manual(which is also linked on this site as well), and saw i had to set the notch on the stator, to a notch or line next it in the housing. (ill take some pics later and upload em, but im hoping you guys can translate my noob-speak lol).
now, the stator itself has 2 sets of lines. one set has "FT" right under them, the other has nothing.
i first set the 2 lines with "FT" to the notch in the housing, the pistons themselves appeared to be at the top of their rotation. and according the manual, i had to set the cam sprocket so the little "O" was at the top as well. slapped it all back together, hand cranked the motor to make sure everything moved nicely, then bolted the head and covers on. went to hand crank again, and it would not move, at all. tried the starter, just to see if that would do it, it didnt.
so i took the cylinder cover off, and it started moving again. not sure what that was all about, but it moves freely now when bolted.
i checked the valves, they were jiggling and very loose, and if i was correct in the screw i was supposed to tighten them with (the loose screws that i had found in the motor), and i hand tightend them til i couldnt wiggle em anymore, then backed em off a hair so i could just barely move em with my hand. (no gapper to check with, so im guesing here)
cranked the motor to test, and it all moved nicely. so i put the plugs in, couple drops of gas in the carb and tried starting it, and it ran. it idled high like before, but it sounded alot smoother than before, so i shut it off, re-attached the gas tank, filled it about a quarter full, set the carbs to stock (fuel out 3 full turns from fully closed, and air 1 and a quarter out from full closed), went to start it and as soon as the plugs fired, it clanked horribly loud and stopped the starter. i hit the button again, and it turned over great, but as soon as it sparks it clanks and stops.
loosened the plugs, thinking they were hitting and that wasnt it. turned it over with the boots to the plugs disconnected, and it turned over great, no clank, no nothing. reconnected, and instant clank.
i cant kickstart it at the moment, because the spindle that the kick lever bolts to, is stripped. i can use vice grips to very slowly, and carefully hand crank it, but starting is out of question.
according to what i have read, it may possibly be a timing issue, essentially, the spark it firing at the wrong time, (the upstroke of the piston), and pretty much stopping it dead in its tracks. also, it may be firing on the wrong rotation of the cycle (exhaust/ intake).
i dont know what im doing here, im just blindly trying stuff, and researching the web to find answers, but ive done all i can without some help from some1 who actually understands this stuff.
thank you so much for the help, and im totally sorry about this massive post
