Restoring Zephanie

[ZoneAdmin]

Good to see the progress you have made with Restoring Zephanie. Good luck with the next stages.

[Stereordinary]

The saga continues…

For the last week I’ve been experiencing some hard starting. Keeping in mind that after I replaced the spark plugs and got it running again, it ran exactly like it did before the accident, almost like nothing had ever happened. I did most of those 80 miles in that time, we’re talking around one month here. It was last Tuesday that I had the first instance of what I am now experiencing every time I start the bike. It has been cold here lately, so I’m sure that doesn’t help.

But basically, my standard startup procedure is, I turn the key, choke on, hit the start button, and engine roars to life. Jumps to about 4k rpm, sometimes a little higher, and then starts to slow. Right around 3k, I roll back the choke while giving it a little throttle to try and hold steady at 3k. Hold it there for maybe thirty seconds, and slowly roll the throttle off. Now what I’m expecting, as this has been typical of the bike since I’ve had it, is that it drops down to maybe 1k. It stays there, and I might rev it a few times, but basically that’s it, she’s ready to ride. After not too long, the idle rises a bit to the manual-recommended 1250rpm.

But lately when I’m rolling the throttle off, it tries to drop down below 1k, and no amount of revving seems to help. Additionally, I’m hearing some strange noises, including what sounds like backfiring. If I hold the throttle open it sounds totally fine at 2k on up. But below that, she doesn’t sound happy. I would not be alarmed at all if this problem alleviated itself quickly, as I would assume this is just a symptom of cold starting, and simply warming up is all that’s really needed. But it is taking a very long time to go away and settle into a nice idle. Plus, I have started the bike on cold days many times, and this has only been a problem recently.

During all that time I spent trying to get it started, I load tested the battery, cleaned the carbs, checked air filter, checked cam chain timing, installed the manual cam chain adjuster, and swapped in new spark plugs. So the only thing I can think of that I haven’t done, that seems like it might be the problem here is… a valve adjustment. Ugh, I really hope that’s not it. I’ve done a valve adjustment before, on a different bike, and it wasn’t easy, and that bike had a simple screw type adjustment. This bike is shimmed. I’m not sure, but that means I would need to have a box full of various size shims to do the job, right? This might be the first thing I’m considering taking it to a shop for.

Any advice, or thoughts on the matter here? I could really use some help.

[Stereordinary]

Aaannnddd… she wouldn’t start at all this morning. Only firing on two pistons. If the history I’ve had with this bike is any indication, the spark plugs are fouled again, and it’s running too rich. Time to do that carb work I’ve been putting off.

[Fishrider]

I feel your pain. The one large issue with this bike is how hard is to work on. Which, I think, is one reason why it is less popular in the States. Top end is okay unless you need to get a bit further in which case you are pulling the engine. Getting those carbs in and out of the boots is always a process, and every time I do it I have fuel issues that need to be solved. Still, I love how this bike looks and rides. Which is why I have dedicated myself to making this one work the way I want. Soul and pocket book.

-Mike

[Stereordinary]

Agreed. I’ve actually found it to be easier to work on than my last bike, but I also haven’t done a valve adjustment on this one yet. But otherwise yeah, I keep spending money on it because it’s just too friggin’ cool.

[Freddy]

Aaannnddd… she wouldn’t start at all this morning. Only firing on two pistons. If the history I’ve had with this bike is any indication, the spark plugs are fouled again, and it’s running too rich. Time to do that carb work I’ve been putting off.

Bit confused. In one post you say you've cleaned the carbs, in the next you refer to 'time to do that carb work I've been putting off'. By the sound of your problem a good carby clean seems the most likely fix. If by planned 'carby work' you're thinking of modifying something .... don't. Nothing but pain awaits in that direction. Make sure everything is stock standard, including a genuine clean oiled air filter, the rubber noise damper is in the throat of the air intake, and the foam surrounding the cage in which the rubber noise damper is located is in tact. If you haven't replaced it, it's guaranteed to be a crumbly mess.

If you haven't done the valves before, they need checking regardless of your problem. It's actually quite a simple job, and no you don't need a box of shims. You just need the correct ones, which you'll determine by measurement and then source them. The quickest and least expensive way is to find an engineering shop specialising in shim manufacture and get the sizes you identify you need posted out. You'll need a good set of feeler gauges and a micrometer or vernier caliper (if adjustment is needed, to measure the current shim) to do the job. The trick to making changing the shims easy is line up the timing marks and then zip tie the chain to each of the camshaft sprockets prior to removal. It then just goes back already in the correct place. Use a new valve cover gasket.

[Stereordinary]

In one post you say you've cleaned the carbs, in the next you refer to 'time to do that carb work I've been putting off'. By the sound of your problem a good carby clean seems the most likely fix. If by planned 'carby work' you're thinking of modifying something .... don't.

I’m just talking about turning the fuel/air mix screws in a quarter turn to lean out the mix at low rpm’s. Unfortunately I can’t do it with the carbs on the bike, so I have to pull them, making it a whole job.

…the rubber noise damper is in the throat of the air intake, and the foam surrounding the cage in which the rubber noise damper is located is in tact. If you haven't replaced it, it's guaranteed to be a crumbly mess.

I have to admit, I have no idea what parts you’re talking about here. Can you circle them on a microfiche or something?

If you haven't done the valves before, they need checking regardless of your problem. It's actually quite a simple job, and no you don't need a box of shims. You just need the correct ones, which you'll determine by measurement and then source them.

Fair enough. I guess I’m just thinking about how once I get in there, check everything, measure, calculate, and know what shim size I need, that’s when I can order the shims, and means I have to wait, unable to ride the bike, until the shims come in. Admittedly not a huge deal, but that’s why I’m probably over inflating it in my head.

[Freddy]

I thought it was a 750, so as its a 550 what I've said may not be appropriate. You can certainly adjust the mixture screws on a 750 with the carbies in the bike. Not easy, but with the right tool can be done. The 'right tool' for me is the flat blade hex bit from an impact screw driver set.

[Stereordinary]

The weather outside absolutely sucks today. Well ok, it’s just rain and it’s not even that cold, but makes it hard to work on my bike. I don’t have a nice big garage, so I’m literally crouched inside my CycleShell.

Anyway, as I’m doing this, a couple of carb-related questions came up.

• I’m thinking it would be nice for me if I could remove the choke lever. And by that I mean the lever at the handlebars, and the attached cable, while leaving the actual slide mechanism at the carbs intact. I could attach a little knob to pull it open at the side of the bike, so it still functions. Why? It just seems to me like less clutter, a nearly microscopic weight savings, and one less cable to detach when removing the carbs. I don’t really see it as an inconvenience to have to reach down to the side of the bike to pull a knob, though I suppose if I’m being dumb and I forget to push it back in, that would be bad. But is there any other reasons why you guys would recommend against this idea?

• The carb float bowl drain screws are JIS philips screws and mine are starting to strip out from too many previous owners using non-JIS drivers on them. Are there allen key socket cap replacement screws available for this, or do I just have to stick with OEM?

• The idle mix knob on the side seems like it is sort of a wonky design with that 90° bend in it, and it always feels like it winds itself back a little in either direction when making small adjustments. Kind of like truing spokes on a bicycle wheel. I was thinking kind of like what I was talking about with the choke lever, I could shorten the whole thing and have it just be the knob directly connected in a straight path, which would place the knob up under the carbs in the middle of the bike. Obviously it’s convenient being able to make adjustments to that knob while seated on the bike, but really it shouldn’t be necessary to do that very often anyway right? Like honestly I have largely been able to set it and forget it, meaning it wouldn’t be a big deal if it was slightly more difficult to get to. But again, is there any reason why this would be a bad idea? I was wondering about making adjustments for altitude and such, but I don’t know if that’s even a concern.

[Stereordinary]

Alright, so where are we at today? Well, about a week ago, I had the carbs out, and I turned the pilot screws in by a half turn each. I thought about being conservative and only doing a quarter turn, but figured with how fast the last set of plugs got fouled, it must be running super rich, and what have I got to lose if I just go for it with a half turn? So far so good. With no other adjustments or modifications (besides new spark plugs), the bike has been reliable and fires up pretty much immediately every time. Kind of also sounds like it's maybe running a little quieter as well? That's probably entirely in my head.

I'm wondering if anyone has any other thoughts or recommendations on what I've discussed so far here. I figure I should keep an eye on the new plugs and watch for fouling. Also curious if my fuel mileage might start to improve.