Ignition Troubleshooting

[stormi]

Sorry to disappear on you like that, it's been a busy week!

So the CDI had some issues eh?? Well at least you got it sorted.  

I'd say your starting issue and your lean condition are related.  Engines like to be rich when starting.  That said, usually we flood the b4s quite easily by pulling too far on the choke ,... what's the position of your choke lever when you're starting? (ideally, we'd not be past about 1/4 - 1/3, but this may be different for you while you're running lean.....)

I'd say 7 month old non-stabilized fuel is definitely not helping at the moment.  If you can drain and replace, that would be a good idea.

Our bikes, because they're stored for up to 7 months of the year are stored with full tanks, but we use seafoam to help the gas not go stale.  

[Vested]

No worries, I've been in the same boat with a move! Also, yes, the CDI was the missing link in the chain of sparking, and thankfully took well to some new caps!

My choke was at full out while starting. I'm moving the bike to my new place tonight, and then will hopefully be able to drain/swap the gas and see what that does.

[stormi]

Yay!! A lot of people here have had to do a similar surgery, I'm glad it worked out for you. 

K,.. if it was full out, and still sounds like it was lean, you may want to look at the cable and see if it's actually pulling at the carb end.  Sometimes they break / seize / who knows and stop doing what we expect.  I would think that at full out you should still have been able to flood the bike,... what happens once the bike is running and you move the choke lever?  does the idle change?  Because at full choke, it should have been racing...

Also check your idle speed setting.  The two of these together can cause some really strange starting / initial running issues.

[Vested]

I'll double check the cable, but before I remounted the gas tank it was working fine in terms of pulling the little slides out. As for idle speed, I have that pretty well set up, idling around 1300 rpm.

So, today. I get the bike fired up, finalize the seat mounting and such, and strap on my helmet. Clutch in, bike in neutral, and I click it down into first, at which point it instantly stalls. I tightened the clutch cable, unscrewing the set screw at the clutch lever until it was pretty tight, and tried again. Again, it stalled the second I went into first, holding the clutch all the way in. Both times it stalled I felt a tiny bit of a forward kick, which makes me think it's catching even though the clutch is in.

One note: I did have the clutch lever pulled tight for about 3 weeks with a ziptie while I was trying to diagnose the spark problem. It allowed me to try to start the bike while having a hand free. Obviously I had it untied while starting it today, but I could see possibly fatiguing a spring through that period?

Thanks for any help!

[stormi]

If I'm reading that right, the kick is pretty normal.  I feel it all the time when throwing the VFR and 919 into gear.  Heck, even the KTM for that matter.

K, first question is - what was the position of the sidestand while doing this? Because what it sounds like is one of the safety switches.

If the stand was down, it did exactly as it was supposed to.

If the stand was up,Check the proper operation of the clutch safety, neutral safety, and sidestand safety switches.

Otherwise, you really need to look at your jetting.  A lean condition can cause stalling issues when throwing it into gear.  You can test this by giving her a small blip on the throttle as you throw it into gear.

A lean condition will respond to this favorably,  switch problems won't care.

There's a good chance that you can get your jetting into a reasonable zone without needing to change the jets, just by adjusting the air or fuel screws (check the service manual to see which one you have.  It escapes both of us at the moment as to which one the b4 has.)

[Vested]

Well, I feel like an idiot now. I actually pulled the sidestand switch because it was giving me some troubles (as was the clutch switch) when I was initially working on the bike. The manual made it appear as if you only needed it for starting, but apparently it's a requirement for running as well? I'll throw it back on and, if it's being a pain, just solder a jumper in before the switch.

As for the screws, the B4 has the air screws on the airbox side underneath little plugs. And as always, thanks! :)

[stormi]

It goes something like this:

If the sidestand is down, the bike must not be able to take off under its own steam. So when the stand is down, it can be started, if in neutral and of course with the clutch all the way in, but if you throw it into gear, it will kill the engine (as you had happen)

I actually use that feature to my advantage.  When I come to a stop, and am about to get off the bike, I throw the sidestand down with the bike in gear to stop the engine.  That way (because of my process) I should never be able to forget to put the sidestand down and get off the bike, which is how a lot of bikes get dropped at the end of a long ride.

Of course it make r_outsider a little crazy I think, because he's  hardwired to expect a bike to be in neutral if it's on the sidestand.  So if he goes to move a bike that I've ridden last, he has a bit of a false start each time.

K,.. so for the air mixture,.. I'd say turn them in a little, til the mixture richens up and the bike wants to start up better for you. (Then adjust your position of the choke lever accordingly)

Are you off the starting fluid yet?

[Vested]

Double checked the manual and it's indeed on the engine side of the carb, not the airbox side, and the screw meters the flow of air/fuel through the fourth pilot hole. Given that, I should be screwing those out to give the engine a bit more fuel, correct?

As for the starting fluid I'm still definitely hitting it for starting, but that's with the old gas still in.

My overarching theory is generally one that aims for simplicity, so I might have to take r_outsider's point. :) The sheer amount of time I've spent with a multimeter checking switches in the bike has me ready to jumper out the sidestand and clutch contacts next time I have the bike apart!

[canyonbreeze]

Correct, turning them out (counterclockwise) will richen the mixture.  Mine are at 4 turns out, a quarter turn either way gives very noticeable acceleration problems for me.

[stormi]

Hey awesome!! Thanks for piping up.  r_outsider and I were trying to remember and were going to take a look through the manual to see if we could refresh our memories on which screws he was talking about, but didn't get very far last night.  It's a lot harder sometimes when you don't have the bike anymore so you can run out and check something, or recent experience working with the bike. 

I can't believe it's been almost a year since we let her go.  I still miss her too.

[canyonbreeze]

Everyone I've talked to that 'used' to have a B400 wishes they still had it. I am planning on keeping mine.

I took a ~3,000 mile trip on mine last week over the Rocky Mountains in Colorado. Since I'm adjusted for sea level here in San Diego I had to lean out the mixture using the above mentioned screws to keep it from stalling out (too much) in the high altitudes like Independence Pass at 12,000 feet.

[Vested]

Plugged the sidestand switch back in, fired the bike up, and off I went! The bike sounded a bit off under low throttle, but the note firmed up nicely once I cracked the throttle a bit more. I do want to play with the fuel screws a bit, just didn't have the proper bit at the time. How will I know when I'm hitting the sweet spot, fuel wise? What's also the best way to spot detonation? I'd rather not explode the engine, you know...

To-do list:
Wire up resistors for turn signals
Figure out why speedometer isn't working
Get lights in tach working
Fuel screws for days

[canyonbreeze]

For my mixture screws the initial acceleration gets worse when the idle mixture is too lean or too rich.  So the sweet spot is the best throttle response.  Engine must be hot and float levels must be correct before doing this or it's wasted time.

If you mean load resistors for LED turn signals, they are a big waste of power.  They just shunt current so the flasher sees the same load as bulb turn signals.  This gives you the same power draw as bulbs and less brightness so it's a net loss.  If you want LED's then get the flasher made for them rather than load resistors.

[Vested]

And again troubles. I've tried to run it a few times since I replaced the capacitors, and it's only fired up once. Though the signal generator is giving good resistance, I did want to pull the clutch cover gasket and make sure it was positioned close enough to the rotor to get a good pulse. Should I be able to pull the starter clutch cover without draining the oil, or is that a "wet" part of the engine?

I started unbolting it as I had thought it was a "dry" section but a couple drops started coming out so I quickly resealed the cover. I want to know whether this might be just an ounce of spillover from somewhere or whether draining the engine/tilting the motorcycle is required.

[stormi]

OK,.. when you say it's not firing up,.. what -is- it doing?  coughing?  firing but not catching?  do you smell fuel?

As for the clutch side of things,.. I know someone will pipe up here,.. but I'd say check the service manual.  it will give you an order of disassembly.  if one of the steps is "drain oil", it's a good indicator there should be oil there.

In a quick look online, it looks like it is a wet side (which was my first guess.)

I just can't help but think that you're going a long ways in, it seems like there should be a simpler solution...  the bike was running before, you didn't crack any of this since, and now it's not running well.  I really want to say it points to something external to the engine...

Speedometer:  check the cable on both ends.  On my Kaboom, it was a busted cable at the wheel end of things.  Simple fix: Honda cable.