Topic: It's running, kinda.... need some help please?

[MCRider]

Stock is 2 and 3 thou. Certainly process of elimination or such would indicate you should go back to 5 and 6 and at least see if that restores the starting. Even if it does, that's not a permanent solution as the lash should be 2 and 3. (Unless its an aftermarket cam. is it?)

However, logically, knowing how all the systems interact, I can't find a reason to expect that valve lash in those ranges affecting startup. I'm open to be educated, but i don't see it.

You should have the lash set properly and then chase down your starting gremlins.

Nor do I think synching is a problem unless its WAY off. usually its a cause for a rough idle, and perhaps rough running on the way up the scale. But not an issue for starting.  Again, I'll defer to other's experience.

[scottly]

I'm guessing you need to start from scratch with your valve adjustment; a couple of thousandths of an inch won't make much of a difference noise-wise. I think you may have set the clearances at the incorrect cam position, and they are way too loose, causing the noise.
You've got to get this bike running right for the relay!!!  

[BrianAdair]

Yes it is a different cam, there is a thread on here some where where I was asking if anyone knew what it was, its close to an RC 315 cam.

Well I don't know why or how it started right up when at .005 and .006 and a mere .002 difference makes it not start....?

But why the loud tapping? has 60psi oil pressure and it will come out the tappet covers so I'm getting oil up top, I'm kinda wondering if the adjustable cam sprocket may have slipped out of time, anyone heard of this happening?

I just don't see how they stay when it has slip notches in it to rotate on the cam, even when torqued down.




I know, I'm trying to get it going I don't want to miss out on the relay.  

[MCRider]

I'm guessing you need to start from scratch with your valve adjustment; a couple of thousandths of an inch won't make much of a difference noise-wise. I think you may have set the clearances at the incorrect cam position, and they are way too loose, causing the noise.
You've got to get this bike running right for the relay!!!  

A couple thou makes a diff in noise, but i guess its all relative to what we're talking about. is it just Buz vs BUZ or is it really CLACK CLACK CLACK.

Which brings in Scottlys really good point that if the settings were done at the wrong cam position not only will it be noisy it would be really hard to start. Hadn't thought of that.

[MCRider]

Jeez man! If its like a RC315, the lash must be no less than 5 and 6 and it will be noisy no matter what you do. That's the character of big bump cams. Live it, love it!  

Ever heard a car with a big bump cam and solid lifters? Sweet sound.

As to the sprocket slipping, yes its possible, but I've never heard of it happening. If you think about it, once the cam gets spinning, its got spring pressure pushing it forward as well as resisting. So I don't really know how much net resistance there is against the cam drive sprocket, but i suspect its less than you think.

[BrianAdair]

Ok.... lol

Just seems noisy to me, its like CLACK CLACK.... lol I would think it would be smooth. but then again if I'm getting too much fuel, would that make it clatter also?

Yea the sprocket I don't know just kinda scary, but as you say probable not as bad as I'm thinking.

[MCRider]

Ok.... lol

Just seems noisy to me, its like CLACK CLACK.... lol I would think it would be smooth. but then again if I'm getting too much fuel, would that make it clatter also?

Yea the sprocket I don't know just kinda scary, but as you say probable not as bad as I'm thinking.

Some hot cams are really noisy. Especially if it was older, early 70s. As time has moved on the technolgy of grinding "ramps" on cams to soften the noise has gotten better. But the most wicked part of the lobe is what hits the rocker first slamming the valve open. The more gentle part of the lobe lowers the valve gently back onto its seat. Pretty hard to make them quiet and never as quiet as stock.

Too much fuel... not an issue as far as noise. Just set them to 5 & 6 and move on.

If you torqued the sprocket bolts and used some mild thread lock, I wouldn't worry.

So you get parking lot braggin rights. Buddies with a good ear can hear you've got something hot under the hood.

[BrianAdair]

I'll take them back to 5 & 6 tomorrow and see what happens. One other thing, do rings have to seat? Seems I'm getting some oil past them through the exhaust, but the plugs don't really show it. But the exhaust pipe has residue in it unless it is excess fuel...? I installed all the rings number side up, and 120* offset, the set had a one piece oil ring.

[scottly]

Ok.... lol

Just seems noisy to me, its like CLACK CLACK.... lol

Even at .006", it should be more of a tick than a clack, .125" would be more of a clack.
I prefer to adjust valves one cylinder at a time, with the piston at TDC on the compression stroke.   

[BrianAdair]

well maybe I'm just thinking it's worse that what it is... It's like a tapping, reminds me of a jeep I had with a colapsed lifter.

[MCRider]

well maybe I'm just thinking it's worse that what it is... It's like a tapping, reminds me of a jeep I had with a colapsed lifter.

Well that could be right. A collapsed hydraulic lifter could sound like a solid lifter, which is what our CBs are.

[scottly]

Can you post a video/audio file? It's awfully difficult to analyze sounds by verbal descriptions!!  

[BrianAdair]

well maybe I'm just thinking it's worse that what it is... It's like a tapping, reminds me of a jeep I had with a colapsed lifter.

Well that could be right. A collapsed hydraulic lifter could sound like a solid lifter, which is what our CBs are.

 I just don't know if I think it gets louder with higher rpm, or if it's just speeding up and not louder.  I may try to get a video of it tomorow with the mic up by the valve cover, not sure if it would help or turn out though, with the way camera mics pick up and change the sound.

[BrianAdair]

Can you post a video/audio file? It's awfully difficult to analyze sounds by verbal descriptions!!  

you beat me to it....

[BrianAdair]

These are some I took the other night but due to the open header you can't hear it as well as you can with the megaphone on.

[scottly]

Great minds think alike..

[BrianAdair]

Think we may have posted at the same time again... There are some videos in my last post. I'll try and get a better one tomorrow.

[scottly]

Doesn't sound that bad in the video, maybe due to the open exhaust? Still, a .002 change in valve lash shouldn't stop it from running. BTW, this change in lash should only require turning an adjustment screw a FRACTION of a turn; do you recall more than that?

[BrianAdair]

Doesn't sound that bad in the video, maybe due to the open exhaust? Still, a .002 change in valve lash shouldn't stop it from running. BTW, this change in lash should only require turning an adjustment screw a FRACTION of a turn; do you recall more than that?

It was probably around half a turn.

Yea the open exhaust covers it up pretty good.


Turning them in didn't really change or quieten the tapping either, I did get it started once but fully choked and running very rough.

[scottly]

I'm guessing most of the noise you were hearing is the infamous CB clutch rattle! It is worst with a motor that isn't running smoothly, whether due to carb sync, carb tuning, or timing issues...   

[BrianAdair]

I'm not sure, sure sounds like it's up top, but I'll give it another try tomorrow with resetting the valve lash, getting it going again with the megaphone on to quieten the exhaust and post the results.

Thank you for the help and your time replying!

I will update tomorrow.

[mlinder]

Brian, good work on getting it running.

I feel like, though, by some of your questions, that there are some holes in your knowledge of how internal combustion engines work, and perhps also you get a little excited and get ahead of yourself which makes you not consider some pretty basic cause-and-effect scenarios.

It seems as if you are asking what to do, and trying to do so, without really trying to understand why people are telling you what they are.

I think you should ask more questions as to why someone told you to try something . This will help you figure out more issues on your own, but more importantly, will help you figure out to what degree everything should/could be adjusted in your build.

Few things are black and white. Nearly everything on your bike is adjustable to some degree, and no one here, without being in front of your bike, can tell you exactly where things should be. We can only throw generalized information in your direction to help get things started.

In any case, I couldn't hea too well in the video, however, remember, your intake valves are only, what, 6 inches from the intake side of the carb, you've got no filters or airbox on them, a lot of valve noise is going to come through there.
A;ways run valves on the loose, noisey side.

[754]

if you really used wire, rather than a drill bit or rod.. to bench synch, it may not be so close.. the straighter the better..
 On a 315 cam, it is set at 12 thou, and its not really that loud.. may be a tad loud at idle, but not revved up.
 Dont worry about idle tight now, and dont let it run a very low rpms if its not running smoothly..

[lordmoonpie]

Ok.... lol

Just seems noisy to me, its like CLACK CLACK.... lol I would think it would be smooth. but then again if I'm getting too much fuel, would that make it clatter also?

Yea the sprocket I don't know just kinda scary, but as you say probable not as bad as I'm thinking.

Hmmm, if you haven't torqued down the slotted cam sprocket it could be that moving. If it's not fully tight, as the engine comes on to compression the camchain tightens on the sprocket on the back, up stroke of the chain and will pull the sprocket around to the far end of the slot. As it goes past TDC the chain pulls harder on the down stroke of the sprocket and pulls it around to the other end of the slot and you get a very audible "CLACK" as it goes from one end of the slot to the other, the sound of the bolt hitting the end of the slot. Worst thing is unless you turn the engine over with the cam cover off you might not see it as the different tenesions on the camchain can actually pull it into a slot position that looks right compared to where you think you left it - the bolts are tight, just not tight enough! Personally I'd get the cam cover off, turn the engine over by the crank and listen for the clacking then. If it is the cam sprocket bolts being too light you don't want to run it like this as you'll be varying your timing all over the place while running and putting the camchain under sudden and very strong loads over the TDC point, increasing the possibility of a break and major engine disaster.

Don't want to be a scaremonger but for a simple check and a bit of time to remove the cam cover/engine you could save a whole world of pain later...you did dial the cam in anyway didn't you?

Had this self same problem with my slotted cam sprocket which is why I raised the possibility. Thankfully I found it while bench testing and not running the engine. The slotted sprocket required a higher torque on the bolts than standard to keep them from slipping - about another 4lb/sq in if I remember correctly...

[BrianAdair]

Brian, good work on getting it running.

I feel like, though, by some of your questions, that there are some holes in your knowledge of how internal combustion engines work, and perhps also you get a little excited and get ahead of yourself which makes you not consider some pretty basic cause-and-effect scenarios.

It seems as if you are asking what to do, and trying to do so, without really trying to understand why people are telling you what they are.

I think you should ask more questions as to why someone told you to try something . This will help you figure out more issues on your own, but more importantly, will help you figure out to what degree everything should/could be adjusted in your build.

Few things are black and white. Nearly everything on your bike is adjustable to some degree, and no one here, without being in front of your bike, can tell you exactly where things should be. We can only throw generalized information in your direction to help get things started.

In any case, I couldn't hea too well in the video, however, remember, your intake valves are only, what, 6 inches from the intake side of the carb, you've got no filters or airbox on them, a lot of valve noise is going to come through there.
A;ways run valves on the loose, noisey side.

Thank you.

Yes, I'm still learning, if it was all stock parts, then I don't think I would have any concerns I would just go off of the Honda manual.
Since it's all NOS performance parts, I wanted to check with all of you that have been here before.

I know, its hard for anyone to know without being right in front of it, I was just looking for ideas or opinions of if I was going in the right/ wrong direction.

I do tend to get excited, and get ahead of myself, at times.