Hey All,
I'm getting ready to address a carb issue that I've been putting off for a while and wanted to get some feedback on my thinking. ('79 special II, stock engine/carbs/exhaust)
Backstory:
a while back I had my bike at the shop to get my new wheels on, etc... at that time I figured I would have them double check my work (I did a half-assed job with my carb-cleaning to get the bike running and wanted them to go through it one more time). I also had found that the PO had torn slide diaphram when putting it back together and while I attempted to repair it, the shop was adamant about replacing it. Which they did.
So, I got the bike back...ran well and all seemed good... although about a month or so later I noticed that sometimes the bike wouldn't pull as hard as it use to...(Kind of felt like I was running on one cylinder but not all the time). A few months later as I addressed some charging issues... I decided to pull the spark plug on the right side (not sure why I didn't earlier) and noticed that it was running really rich on the right side (same side as the torn diaphram)... while the right carb's mix screw was set pretty much stock 2 1/4, the plug was heavily sooted. So I did the dead-cylinder method and found that the right side mix screw way off compared to the stock setting...anything more than 1 1/4 turn would have the bike running too rich on that side...and even fully closed it was still getting a little fuel... so clearly something's off. I've since kept it at that setting so that it's running "better" and enjoyed the summer riding months... but it's bugging me and now that the weather is turning, I'm going to address it.
Note: Bike pulls pretty well through the full range. There is a very (very) little flat spot when cold getting past 1500rpms, but then it's gone and doesn't come back AT ALL after start up...and there is a little tach needle bounce at idle...+/- 100 rpms (Which I've tried to balance/sync out but that's as good as I can get it).
On to my thinking... Since the bike is stock engine/exhaust etc... and carbs were stock except for the replaced slide/diaphram, I'm thinking that the jet needle was put in either a clip or two too high... or there's some other issue....like maybe a float height setting issue...(maybe a very small air leak?) or all the above?
All of which I'll check, but just wanted to see if this line of thinking makes sense?
Thanks all!
I'm getting ready to address a carb issue that I've been putting off for a while and wanted to get some feedback on my thinking. ('79 special II, stock engine/carbs/exhaust)
Backstory:
a while back I had my bike at the shop to get my new wheels on, etc... at that time I figured I would have them double check my work (I did a half-assed job with my carb-cleaning to get the bike running and wanted them to go through it one more time). I also had found that the PO had torn slide diaphram when putting it back together and while I attempted to repair it, the shop was adamant about replacing it. Which they did.
So, I got the bike back...ran well and all seemed good... although about a month or so later I noticed that sometimes the bike wouldn't pull as hard as it use to...(Kind of felt like I was running on one cylinder but not all the time). A few months later as I addressed some charging issues... I decided to pull the spark plug on the right side (not sure why I didn't earlier) and noticed that it was running really rich on the right side (same side as the torn diaphram)... while the right carb's mix screw was set pretty much stock 2 1/4, the plug was heavily sooted. So I did the dead-cylinder method and found that the right side mix screw way off compared to the stock setting...anything more than 1 1/4 turn would have the bike running too rich on that side...and even fully closed it was still getting a little fuel... so clearly something's off. I've since kept it at that setting so that it's running "better" and enjoyed the summer riding months... but it's bugging me and now that the weather is turning, I'm going to address it.
Note: Bike pulls pretty well through the full range. There is a very (very) little flat spot when cold getting past 1500rpms, but then it's gone and doesn't come back AT ALL after start up...and there is a little tach needle bounce at idle...+/- 100 rpms (Which I've tried to balance/sync out but that's as good as I can get it).
On to my thinking... Since the bike is stock engine/exhaust etc... and carbs were stock except for the replaced slide/diaphram, I'm thinking that the jet needle was put in either a clip or two too high... or there's some other issue....like maybe a float height setting issue...(maybe a very small air leak?) or all the above?
All of which I'll check, but just wanted to see if this line of thinking makes sense?
Thanks all!