Chrispy
XS650 Enthusiast
Good morning gentlemen
this is both my first post here and my first real motorcycle. I have scoured this website over the past couple weeks and it’s plethora of technical information has been invaluable. I have absorbed more information from you guys than I did in four years of college. I have now hit a wall though and feel I must ask some questions directly, some of them will be dumb but sometimes that’s just how it has to be
Backstory on the bike, bought it off a very frustrated man who won it in a bike week lottery. It was not running when he got it but He sent it to a local guy specializing in old bikes who got it working. He had put about 1000 miles on it when a float got stuck and was leaking gas out the air filter. At that point he remembered why he had sworn off carbureted bikes, and sold it to me for cheap. I knew nothing of bikes at the time but I got the carbs out, cleaned them as well as someone who has never seen a carb can, and put them back and it kicked up.
Over the past couple weeks I have trouble shot like a madman, mostly electrical, and learned a lot about the bike, so here are the stats I have for you.
This guy is pretty stock 77 or 78. It’s got points and what seems to be the original alternator. Alternator has fresh brushes now (they were literally 1mm nubs) and the voltmeter I installed shows solid charging in the 14 range over 3000 rpm. The owner before the guy I bought it from had put those Red Mike’s xs filters on that everyone hates, and my guy put the stock air boxes back on. Did either of them re-jet? God only knows. Also at some point a 2 into 1 exhaust system was put in. Did they re-jet? See above exclamation.
Needless to say I’m pretty sure it needs a rejet. The bike feels really flat between 3-5k rmp and it not very responsive and you really gotta open it up for hills to maintain speed. Again I’ve not ridden a lot of old bikes so I’m going on instinct but I’m pretty sure it’s supposed to pull better than that.
So with all that in mind here are the questions I haven’t been able to work out myself.
1. Any recommendations for rejet with stock air boxes and the pictured exhaust? I know I could test a litany of jet and needle combinations and if that’s what’s necessary I’ll do it. I just thought maybe it’s out there already.
2. This one is embarrassing but I have to ask. How in the name of sweet heaven are you guys getting to the mix screw while it’s on the bike. I’ve bench synced them as best I can but my god I’ve tried every combination of taped together tools to reach that thing and I can’t. Please help me.
3. Points and original alternator. Should I keep em or sweep em. How likely are they to strand me somewhere.
4. Is there anything I might have missed that will need attention. I’ve done valve clearances, timing, and solved some shorts but planning a rewire.
5.
edit; repeated pics removed. ggg
How you guys doin today? I appreciate anyone who read all that. Any help is a huge.... help. Thats my sign off line I guess.
this is both my first post here and my first real motorcycle. I have scoured this website over the past couple weeks and it’s plethora of technical information has been invaluable. I have absorbed more information from you guys than I did in four years of college. I have now hit a wall though and feel I must ask some questions directly, some of them will be dumb but sometimes that’s just how it has to be
Backstory on the bike, bought it off a very frustrated man who won it in a bike week lottery. It was not running when he got it but He sent it to a local guy specializing in old bikes who got it working. He had put about 1000 miles on it when a float got stuck and was leaking gas out the air filter. At that point he remembered why he had sworn off carbureted bikes, and sold it to me for cheap. I knew nothing of bikes at the time but I got the carbs out, cleaned them as well as someone who has never seen a carb can, and put them back and it kicked up.
Over the past couple weeks I have trouble shot like a madman, mostly electrical, and learned a lot about the bike, so here are the stats I have for you.
This guy is pretty stock 77 or 78. It’s got points and what seems to be the original alternator. Alternator has fresh brushes now (they were literally 1mm nubs) and the voltmeter I installed shows solid charging in the 14 range over 3000 rpm. The owner before the guy I bought it from had put those Red Mike’s xs filters on that everyone hates, and my guy put the stock air boxes back on. Did either of them re-jet? God only knows. Also at some point a 2 into 1 exhaust system was put in. Did they re-jet? See above exclamation.
Needless to say I’m pretty sure it needs a rejet. The bike feels really flat between 3-5k rmp and it not very responsive and you really gotta open it up for hills to maintain speed. Again I’ve not ridden a lot of old bikes so I’m going on instinct but I’m pretty sure it’s supposed to pull better than that.
So with all that in mind here are the questions I haven’t been able to work out myself.
1. Any recommendations for rejet with stock air boxes and the pictured exhaust? I know I could test a litany of jet and needle combinations and if that’s what’s necessary I’ll do it. I just thought maybe it’s out there already.
2. This one is embarrassing but I have to ask. How in the name of sweet heaven are you guys getting to the mix screw while it’s on the bike. I’ve bench synced them as best I can but my god I’ve tried every combination of taped together tools to reach that thing and I can’t. Please help me.
3. Points and original alternator. Should I keep em or sweep em. How likely are they to strand me somewhere.
4. Is there anything I might have missed that will need attention. I’ve done valve clearances, timing, and solved some shorts but planning a rewire.
5.
edit; repeated pics removed. ggg
How you guys doin today? I appreciate anyone who read all that. Any help is a huge.... help. Thats my sign off line I guess.
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