Author Topic: Weber + ARD Mag setup no start issue  (Read 5048 times)

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Offline valt

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Weber + ARD Mag setup no start issue
« on: June 22, 2020, 06:59:46 am »
Hey All,

I wanted to reach out and see if I can get any help here. I have been working on this bike for about 7 years now and its finally to the point of being nearly done. The motor is a k motor bored out to 850cc using a cyclexchange kit (that he no longer offers), the motor also has a MLS head gasket. It also has a set of DCOE 40 carbs (That I rebuilt completely) on a copy of a Russ Collins manifold. It also has a ARD magneto which was completely rebuilt and tested by Mainley Magnetos. I will go ahead and break down the testing I have done so far with the motor:

Compression is even at about 170psi on all four cylinders.
Ignition wires were changed to solid copper core wires and firing order was confirmed multiple times (1,2,4,3).
Igniting timing was confirmed and the housing was marked to indicate cylinder #1 firing.
Tested with round top carburetors and starter fluid.
Removed and re-seated carb boots to verify no intake leaks.
Plug gaps were verified and new plugs installed.
Verified that cam timing was set correctly.
Web cam removed and stock cam installed.

I should note that this motor ran about a year ago and this was with no throttle control at all. It didn't run very well but it ran at least which you can see in the below video:



The only thing that I changed since then was I removed the head to chase an oil leak. When I put the head back on I went ahead and installed new valve springs from cyclexchange (Part #ENV-008). I also installed a CX-1 cam from cyclexchange, which I have removed at this point and installed the stock cam. I have a stock motor (at least as far as I know), I put my weber and mag setup on it and it basically immediately starts. In fact thats the motor I have been running to do my shake down runs in this video:


A lot of the hard starting here is just me not having the webers setup correctly and not knowing how the motor wants to start. I have been working on this for the past 2 months and I am getting no where with it. I can get the big bore motor to fire on a couple of cylinders but it never acts like it wants to run.

Any help would be unbelievably appreciated here.


Online 754

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Re: Weber + ARD Mag setup no start issue
« Reply #1 on: June 22, 2020, 09:43:12 am »
 I am wondering why the carbs  are not level ?
 I can help I have run these on my bikes.
 Are you on Instagram ? Think I may have talked to you on there about this before ?
 The RC manifold  usually used CB 350 twin cables going to out side of carbs , on the RC manifold, they are real close together between carbs. Do you have threaded holes at the outer edge of manifold for the cables ?
« Last Edit: June 22, 2020, 09:46:47 am by 754 »
Maker of the WELDLESS 750 Frame Kit
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My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

73 836cc.. Green, had it for 3 decades!!
Lost quite a few CB 750's along the way

Offline valt

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Re: Weber + ARD Mag setup no start issue
« Reply #2 on: June 22, 2020, 09:51:13 am »
I'm not sure if you have reached out to me on instagram but its possible. My instagram is @csavoldi, as far as them not being level I'm not sure what you are referring too. Based on what I have seen of other R.C. setups they are mounted the same. Also I don't believe that their orientation has much to do with the motor running or not, as I put probably 25 miles on the other motor with them like that and it actually ran pretty well.

Regarding the cable, I can't use a CB350 cable in my setup as its to short. I'm using a modified scooter cable currently. In the video where I am riding you can see this actually.

Online 754

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Re: Weber + ARD Mag setup no start issue
« Reply #3 on: June 22, 2020, 04:22:53 pm »
Yes i have talked to you I think first time you started it...I am effinoffbros, I think it is
 The 350 cable has a splitter and 2 short cables, the long one you probably need to change.
Maker of the WELDLESS 750 Frame Kit
dodogas99@gmail.com
Kelowna B.C.       Canada

My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

73 836cc.. Green, had it for 3 decades!!
Lost quite a few CB 750's along the way

Offline valt

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Re: Weber + ARD Mag setup no start issue
« Reply #4 on: June 22, 2020, 05:12:54 pm »
To my knowledge the 350 cable is one piece, I understand it has a splitter but its not possible to take it apart. I have several 350 cables and the splitter section is just a slider but you can't change any part of that cable. In any case I have a cable that works and that is not the cause of the motor not running.

I can go pull one of those cables apart to verify but I'm almost positive thats the case.

https://www.dimecitycycles.com/vintage-cafe-racer-caferacer-bobber-brat-chopper-custom-motorcycle-cables-honda-cb350-cl350-throttle-cable-02-0000.html
« Last Edit: June 22, 2020, 06:57:13 pm by valt »

Offline scottly

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Re: Weber + ARD Mag setup no start issue
« Reply #5 on: June 22, 2020, 10:54:25 pm »
Your carbs are angled more than normal, even for an RC setup.
https://www.youtube.com/watch?time_continue=10&v=Wg9WT7zzDj8&feature=emb_logo 
I'm not sure I understand your problem; is it the hard starting shown in the first video, where it does eventually start? Not having a throttle hooked up doesn't help matters, and I also suspect ignition timing, since the mag has no advance mechanism.
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Offline valt

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Re: Weber + ARD Mag setup no start issue
« Reply #6 on: June 23, 2020, 06:17:03 am »
Your carbs are angled more than normal, even for an RC setup.
https://www.youtube.com/watch?time_continue=10&v=Wg9WT7zzDj8&feature=emb_logo 
I'm not sure I understand your problem; is it the hard starting shown in the first video, where it does eventually start? Not having a throttle hooked up doesn't help matters, and I also suspect ignition timing, since the mag has no advance mechanism.

I should make it clear that the first two videos are from a year ago and before I had a throttle cable. The second video where I am riding is just showing that the setup works on a stock ish motor. Currently the motor does not run and I can really only get a few pops out of it.

I will go ahead and bring it up again. But on the stock motor it actually ran fine, I rode it around for several days. It was fairly easy to start and revved cleanly, it certainly needed some tuning but ran more or less without a hitch.
« Last Edit: June 23, 2020, 06:30:46 am by valt »

Offline scottly

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Re: Weber + ARD Mag setup no start issue
« Reply #7 on: June 23, 2020, 06:04:23 pm »
Try swapping the 1 and 4 plug wires at the mag cap.
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Offline valt

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Re: Weber + ARD Mag setup no start issue
« Reply #8 on: June 24, 2020, 06:55:18 am »
Try swapping the 1 and 4 plug wires at the mag cap.

I have verified that the ignition is correct. In fact I have labeled the number 1 spark plug wire so I don't forget. Also if I put this mag on my stock motor it runs fine, that includes using the exact same spark plug wire layout.

Online 754

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Re: Weber + ARD Mag setup no start issue
« Reply #9 on: June 24, 2020, 09:36:37 am »
If accelerator  pumps work, and you turn the throttle part way,  it should fire every time you kick it. May not stay running.
 We're the carbs on a bike before , matched set, or were they separate carbs that you changed the jetting on ?
And did you work on the accelerator pumps at all ?
Maker of the WELDLESS 750 Frame Kit
dodogas99@gmail.com
Kelowna B.C.       Canada

My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

73 836cc.. Green, had it for 3 decades!!
Lost quite a few CB 750's along the way

Offline valt

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Re: Weber + ARD Mag setup no start issue
« Reply #10 on: June 24, 2020, 09:55:52 am »
I completely rebuilt those carburetors and I am using jetting that was recommended by Kiyo. Those first two videos where the bike is running with the big bore motor are those exact carburetors. I have changed nothing about them since the last time it ran. The accelerator pumps work correctly, I will try and get a video showing exactly what the bike does now.

Offline scottly

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Re: Weber + ARD Mag setup no start issue
« Reply #11 on: June 24, 2020, 09:57:30 am »
Since the carbs and mag worked on a different motor, they are OK, and I suspect an installation problem, like the mag is 180* out. Swap the #1 & 4 wires at the cap and see if it starts firing on two cylinders. Just takes a second to try it. ;)
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Offline scottly

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Re: Weber + ARD Mag setup no start issue
« Reply #12 on: June 24, 2020, 09:58:06 am »
Who is Kiyo?
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Offline valt

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Re: Weber + ARD Mag setup no start issue
« Reply #13 on: June 24, 2020, 10:22:21 am »
I went ahead and swapped 1&4 and now only 2&3 fire which makes sense. Since I have checked the spark plug wire routing several times.

Kiyo runs Kiyo's Garage, he has built several weber / ard powered 750s as well as turbo bikes and a dual motor'd bike.

https://www.kiyosgarage.com/bonneville

I went ahead and took a video showing what it does right now when I try and start it. Mind you the mag is set to fire at the full advance mark (this is how it is supposed to be set as there is no advance in the mag).


Online 754

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Re: Weber + ARD Mag setup no start issue
« Reply #14 on: June 24, 2020, 10:39:00 am »
It sounds like its not getting fuel , I don't know if you are aware of it, but the inlet seat is drilled out  for gravity feed use, ie no fuel pump.... when setting them up for bike use.
 
 I still can quite grasp how you got the carbs to that angle? And it maybe related to your problem
 There us a member on here with an ARD and Webers , his starts fine..
 As far as starting, many of the guys don't use the chokes, just prime, kick, and keep it running..
« Last Edit: June 24, 2020, 10:40:31 am by 754 »
Maker of the WELDLESS 750 Frame Kit
dodogas99@gmail.com
Kelowna B.C.       Canada

My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

73 836cc.. Green, had it for 3 decades!!
Lost quite a few CB 750's along the way

Offline scottly

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Re: Weber + ARD Mag setup no start issue
« Reply #15 on: June 24, 2020, 10:51:01 am »
I never drilled out an inlet seat, Frank, although Weber makes different sizes of float needles and seats. The boots look to be rotated to line up with the manifold? IIRC, the RC manifold has the spigots off-set from the center of the throats. Still, that doesn't explain why it worked before swapping the head, or why the setup works on a stock motor.. Doesn't Bill have his mag set a 24* advance?
Valt, have you verified the timing with a strobe?
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Offline valt

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Re: Weber + ARD Mag setup no start issue
« Reply #16 on: June 24, 2020, 11:19:34 am »
It sounds like its not getting fuel , I don't know if you are aware of it, but the inlet seat is drilled out  for gravity feed use, ie no fuel pump.... when setting them up for bike use.
 
 I still can quite grasp how you got the carbs to that angle? And it maybe related to your problem
 There us a member on here with an ARD and Webers , his starts fine..
 As far as starting, many of the guys don't use the chokes, just prime, kick, and keep it running..

Again you can see in the the video where I am riding the bike it starts just fine and the carbs are at exactly the same angle. The bike is 100% getting fuel as I verified that all accelerator pumps are working.

I don't have a strobe that works with the mag unfortunately. All of my timing lights will only intermittently light up with the mag. The way I verify timing is there is a mark on the mag body and a mark on the wheel that drives the mag. That mark indicates when the mag fires #1, so I pull the mag and put on a stock advance mechanism and move the motor to where cylinder #1 is firing at full advance. Then make sure when I put the mag on the two marks line up.

I should also note that I have moved the timing advanced and retarded in small increments both ways. The only time it does much of anything is when it is set as it is now.
« Last Edit: June 24, 2020, 11:32:25 am by valt »

Offline scottly

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Re: Weber + ARD Mag setup no start issue
« Reply #17 on: June 24, 2020, 11:43:33 am »
In the first post, you mentioned testing with round-tops and starting fluid, but didn't say what the results were?
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Offline valt

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Re: Weber + ARD Mag setup no start issue
« Reply #18 on: June 24, 2020, 11:45:56 am »
In the first post, you mentioned testing with round-tops and starting fluid, but didn't say what the results were?

Yeah sorry, it would not start on the round tops either. I brought the motor to a shop with the round tops and the mag. They stated they were able to get it to briefly run with the round tops and starter fluid. But I have not been able to reproduce that.
« Last Edit: June 24, 2020, 11:49:17 am by valt »

Offline scottly

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Re: Weber + ARD Mag setup no start issue
« Reply #19 on: June 24, 2020, 11:50:48 am »
Swap a stock points setup on temporarily, if it runs, you can rule out the carbs and focus on the mag. Also, Webers are supposed to be mounted level, or sloping down at the rear up to 5 degrees.
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Offline valt

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Re: Weber + ARD Mag setup no start issue
« Reply #20 on: June 24, 2020, 11:54:13 am »
Swap a stock points setup on temporarily, if it runs, you can rule out the carbs and focus on the mag. Also, Webers are supposed to be mounted level, or sloping down at the rear up to 5 degrees.

I don't really have a points setup that I could put on this bike. It is in no way setup for a set of normal coils and points ignition. The mag works fine, which again you can see if the video of me riding the bike. It has the mag on it and I could if I wanted put the mag on the other motor and have it basically start right up. I can get you a video of me doing just that if you want. All that really proves though is that the mag works without issue.

Offline scottly

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Re: Weber + ARD Mag setup no start issue
« Reply #21 on: June 24, 2020, 12:10:51 pm »
I don't really know what to tell you? You say everything is correct, including cam timing, but from some reason the setup works on the other motor but not this one. I have heard in the past that the ARD pulley on the crank-shaft tends to move, shifting the timing. One member got fed up with it and installed a regular ignition under the ARD cover. ;D One thing I noticed, when a motor fires, but can't quite get actually running like yours, the ignition timing is retarded.
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Offline valt

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Re: Weber + ARD Mag setup no start issue
« Reply #22 on: June 24, 2020, 12:29:15 pm »
That certainly is what it sounds like to me as well, it sounds lazy like the timing is retarded. But if I advance the timing I get nothing. I really haven't noticed any issues with the timing moving, as I have pulled it off and verified after it ran on the other motor for a while.

Offline scottly

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Re: Weber + ARD Mag setup no start issue
« Reply #23 on: June 24, 2020, 06:39:30 pm »
I thought of a way to verify static timing, sort of. (Ignition systems that have no timing marks and can't be checked dynamically with a strobe like C5/PowerArc piss me off >:()
Connect an ohm meter between ground and the "kill" terminal on the mag. When the points are closed, the meter should read a very low resistance,like as close to zero as your meter can read, and when the points are open, the resistance should increase, but I'm not sure how much. Slowly rotate the motor until the points first open, then put the stock advancer on to see where the timing is. 
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Offline livefast_dieold

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Re: Weber + ARD Mag setup no start issue
« Reply #24 on: June 25, 2020, 06:35:20 am »
Just throwing this in the mix, as I experienced it in my race engine: have you checked that the valves didn't hit the piston and then bend a little when you were using cycle-x camshaft? Probably not since you have checked compression...

I remember my engine was behaving exactly like yours when this happened to me, although I bent a couple of valves after missing a gear and consequently the engine revved past the red line.

If I were in you I would probably double-check cam timing anyway...