1976 Running Rich

[Wilsonsk]

How often you need to clean them and re-oil will depend how dusty it is in your area. It's not very dusty where I live so I only clean them maybe every 4 or 5 years. For the breather hoses, we use a $5 power brake check valve from the auto parts store. It fits perfectly in the end of the stock hose and being a 90° configuration, directs any oil or oil mist that may come out back through the pod filter .....

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That later single output breather is a nice little upgrade. I would swap it out for your current double output one. Then you'll only need one check valve .....

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If you swap the breather, swap the whole thing, guts and all (internal baffle plate). You would probably have to anyway as I don't think the baffle plates are the same.

I’ll swap the breather over. I got my VR115 installed this week, I have the new rectifier, I’ll put that in when I do the pod swap, much easier to get to it then. I’ll take the carbs off and give them a look too, make sure some stray chunk of something didn’t get somewhere, rejet them while they’re out. Pipes, mufflers and pods will all be here Tuesday. I’ll do all of that at once.

 

[Wilsonsk]

Got my stuff today, I checked to see if the mufflers would fit on my head pipes, the do, a little tight but they clamp on well. Look nice, quieter than my short megaphones with sink strainers, I didn’t get on it much, ran to a meeting, but the little I got to get on it, ran fine. This morning I took the right side plug in the choke circuit out and sprayed carb cleaner towards where it goes into the throat. I think that may have been some of my cold start issue, it seemed like the right cylinder wasn’t firing much on choke, now it idles pretty smooth on choke cold. I’ll get started on the pods and head pipes and rejetting on Sunday, I’m fairly busy between now and then.

 

[Wilsonsk]

Went out and rode about 20 miles, running great, still just the new mufflers, very quiet, has perked up the top end. Interesting baffle design they have, I'd like to see a cutaway of it. I was checking some things over when I got back, the screw that holds my choke lever on vibrated out so the lever is gone, I ordered one from Mikes, I was missing the rubber part anyway.

 

[5twins]

Your Commando mufflers should have come with a couple large, short Allen bolts. These are to plug a hole in the center of the baffle plate .....

I tried mine both ways, with and without the plug bolt, and I prefer them with it. It doesn't quiet them down much but it does mellow the tone and make it less raspy.

 

[Wilsonsk]

Your Commando mufflers should have come with a couple large, short Allen bolts. These are to plug a hole in the center of the baffle plate .....

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I tried mine both ways, with and without the plug bolt, and I prefer them with it. It doesn't quiet them down much but it does mellow the tone and make it less raspy.

I didn’t realize that’s what they were for, I’ll give it a try. With my head pipes the commandos end right about the axel, I really like them there, looks like the new head pipes are a bit longer, I may have to cut them, for the time being I’m fine with my old head pipes, they aren’t perfect but good enough for now. As I clean things up more I’ll get the better parts on. The back pressure must be pretty similar to my short mufflers, and they are quite a bit quieter, sounds pretty stock, I’m good with that, I was trying to get mine quieter in the first place. I didn’t change any jetting and I think it runs even better, it’s running great, started it cold just now to put it in the garage, choked it and hit the starter and it just starts and idles now, no throttle required.

Edit: I put the bolts in, sounds good in the garage, it’s raining out so I may be able to try them tomorrow or Friday.

 

[Wilsonsk]

Got the pods on, I put the 130 mains, 27.5 pilots, needles 1 groove lean (2nd groove from the top), I didn’t get too much time on it, the little I got to get on it, seems to pull smooth through the 4,000-5,000 range, the low end stumble is back, I’ll play with the mixture screws later, if I can’t get it out, I’ll go back to my 25s which may not be 25s any more.

 

[Wilsonsk]

Got out an rode a few miles, I experimented with the mixture screws, went out to about 2 1/2 turns and in to about 1/2 turn, changing it while it's idling does seem to affect the idle speed (shooting for ~1,300). It doesn't really help the stumbling from a dead stop, I can nurse it past the stumble, then it runs great, closing the throttle and engine braking results in some popping, coming up to stop signs the idle seems to either sort of "race" briefly, then slow down, or just go down to almost dying, or idle where it should. Anything off of idle seems just fine. I think I'll try my original pilots again, since I have them on hand. I really like the space removing the airbox makes, could put a tool box in there or something.

 

[Wilsonsk]

I got out and rode some more, I worked my way in to a half turn on the mixture screws, went back to 2 1/2 turns, then 3, then 3 1/2. Runs the best it has since putting the pods on this morning, I’ll ride it down to Dennis Kirk tomorrow and get #30 pilot jets.

 

[Wilsonsk]

Put the 30 pilot jets in, didn't really improve anything, about the same. I think I'll try my original pilots again, that's the last known ones I had in there that ran decent on the bottom.

 

[Wilsonsk]

I switched back to my original "25"s, this ran the best so far, semi warmed up, maybe most of the way warmed up, but in the 5-6 mile loop I ride to test this, About 3-4 miles in it has start to act like its running out of gas. If I stop and restart it, it will go for a while, then continue to act like it's running out of gas (I put it on RESERVE, it seems to fix it briefly, not sure if it does anything at all). It had done this a couple of times before I started messing with jetting. The aftermarket petcocks don't shut off completely, maybe they can't deliver enough fuel? It seems to do it when I run over 60 mph for any length of time. The bike is very comfortable at 70, but fuel delivery seems to be an issue at that speed. I'll start a new thread on that, maybe others have had the problem?

All of that to say, until I had fuel delivery issues, the "25"s seemed still to be the best. I think I need to sort out my fuel delivery problem now.

 

[Wilsonsk]

My rejetting has been derailed by some sort of high speed/load power loss issue, thought it was the gas cap vent, not that, need to sort that out as it has been affecting the results of my rejetting tests. I started a new thread for that.

https://www.xs650.com/threads/1976-xs650-starving-for-fuel.64789/#post-806484

 

[Wilsonsk]

Seems that my fuel starvation appears to be a bad coil. It seems it was also messing with idle and low end too, so all of those jet changes were not really necessary, I wound up back at my original jets, now that it is running decent (put one of the original coils back on), turns out my original jets work with about 3 1/2 turns on the air screws, so, I’ll get those 27.5s in again tomorrow. The plugs looked good, light brown (right one was darker, bad coil) so I’m probably ok with the 130s, needle is one groove lean (2nd groove from top), pulls hard all through the rpms.

 

[Wilsonsk]

While I still haven't change any jets, I'm still exploring some charging wonkiness, my cold starts seem to be nice and smooth again, choke, hit the start, it sits and runs pretty smoothly on both cylinders, a minute or 2 of that then choke off, it slows but sits there and idles pretty regular, I don't move it until the valves stop making noise, then it runs pretty good, still a little cold blooded for the first block or so. Much more like it had been early in the revival.

 

[Wilsonsk]

Still haven’t got back to jets, but it appears my charging issue was dirty slip rings. Back to jetting tomorrow.

 

[Wilsonsk]

I put my 27.5 pilot jets in, it seems pretty good, still seems to want to be 2-2.5 turns out on the mixture screws, not sure if I should put in the 30s? Stumbles a lot cold, once warmed up, occasionally stumbles off idle. I've been trying to keep the idle at 1200 as I make adjustments. Fortunately (fingers crossed) my Emgo coils were the culprit to what I thought was fuel starvation. Time (and more riding) will tell.

 

[Wilsonsk]

I'm still having some cold start issues, it's better, still have the 27.5s in, it starts fairly quickly, wants choke for quite a while, pops back through the carbs sporadically, less and less as it warms up, but it will take almost no throttle to get it to pop while running on choke. I'm 2.5-3 turns on the screws now, my 2 stroke experience says popping means lean, move up to 30 pilot jets?

 

[jpdevol]

I think so, but I like to be a tad on the rich side so the choke is only needed for 30sec or so...I might double check for air leaks at this point too though.

 

[Wilsonsk]

I’ll check for leaks before I put the 30s in, I put new carb mounts on when I rebuilt the carbs and used the thick gaskets. I check for leaks at the beginning of the process but I’ll do it again. My two stoke experience agrees with one step rich, stakes are a little higher with those. I will pull the carbs at some point and go through them good again.

 

[Wilsonsk]

I still haven’t put the 30s in, but i did get out and put some miles on, I also swapped back to the 17 tooth sprocket, much happier there, I see 5twins perspective on 17/33, I think I’m going to pickup a 33 for the back. I’ll get pilots swapped over the weekend.

 

[Wilsonsk]

I put the 30s in and checked for vacuum leaks (non found). I’ve put about 60 miles on today, still seems cold blooded, but I’m learning a routine, start with choke on, no throttle, for a few seconds, choke off briefly, then choke back on, then the idle will pick up and it can idle for a minute or two with the choke on. Even if I let it warm up for 5 minutes off choke, it will still spit and sputter under load off idle for a few blocks, once fully warmed up, it seems to run pretty good. I got it good and hot and then worked on mixture screws. Best idle and performance seems to be 2.5-3 on the left 2-2.5 on the right. There is still an occasional stumble off idle, but not horrible and revs seems to come down pretty quick. Seems like I probably should try 32.5s? I saw a guy do a good explanation of how the pilot and mixture screw work together, it does a good job of explaining why you can’t really make up for pilot jetting with the mixture screw, some latitude maybe, and a necessary tool in dialing in the pilot jet, but not a replacement. It’s 95 here today so my tolerance for leaning over a running air cooled engine trying to keep a screwdriver in a vibrating slot is about at its limit…for an hour or so anyway.