Fitting CV carb on panhead

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aeroden
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Fitting CV carb on panhead

#1

Post by aeroden »

Hi everyone,

My first post here, so please bare with me if did not follow some well-known etiquette.

My friend has 1958 panhead with S&S Super B carb. It works fine once we manage to start it, but starting itself is a nightmare, particularly when it's below 60 degrees outside. My friend, which is more tech savvy than me, thinks it is related to the fact that the bike has belt conversion kit on primary, that decreases ratio between kick and crank, and as result, engine spins much less when kicking.

We also go our hands on HD CV carb, and after reading online it looks like it can solve our issues. However I don't know which jets, bowl fluid level, pilot jet setting we need to start through. Can anyone shed some light or provide reference to the relevant materials? Carb model is HD 27038-92. Pipes are not stock - see the below vid. We don't think there are any other engine mods.

The bike has a long history - served in police first, then was converted to chopper. We plan to restore it to close to original looks, but want to solve the mechanical mysteries first.

Thanks everyone in advance.

Short YouTube vid of the bike: https://www.youtube.com/watch?v=A-ihGAP7L8k
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Re: Fitting CV carb on panhead

#2

Post by Lowbikemike »

Turn the idle up on that thing........it may sound good loping like that but you are not helping anything.

In my opinion the belt drive conversion has nothing to do with a starting issue.

What is your starting routine? Have you checked for intake leaks? Where is the timing? That looks like an auto advance or newer style timer, is it set correctly. Probably a host of other non carb issues that could be causing the hard starting. Look there first before changing carbs.
aeroden
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Re: Fitting CV carb on panhead

#3

Post by aeroden »

Lowbikemike wrote:Where is the timing?
What do you mean exactly? - How did we configure ignition timing?
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Re: Fitting CV carb on panhead

#4

Post by Bigincher »

aeroden wrote:
Lowbikemike wrote:Where is the timing?
What do you mean exactly? - How did we configure ignition timing?
I'm sure that's what he meant.

My suggestion is to check that the clutch is not slipping. If the primary is still enclosed, remove the derby cover to observe the clutch while someone is kicking the motor over. If the clutch slips, it will not fully turn the motor over fast enough for it to start. Just something to check while you're chasing your tail.
If the clutch is not slipping, and if it does have an auto-advance ignition timer, that's the likely culprit. Make sure it is functioning freely and going into retard when the motor shuts off.

And I ditto the warning on the low idle. You will kill that motor if you let it idle too low!!
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Re: Fitting CV carb on panhead

#5

Post by Lowbikemike »

Yes, I meant where do you set the timing and how did you set the timing?
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Re: Fitting CV carb on panhead

#6

Post by VPH-D »

Are you keeping the throttle closed while using the enrichening device to prime the engine?
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Re: Fitting CV carb on panhead

#7

Post by Frankenstein »

Just listening to the video, the timing sounds too advanced at idle for a auto timer unit. Also, as mentioned earlier, unit might not be functioning properly? I'd check idle mixture, air leaks as well. It shouldn't affect starting, but is there a non stock cam in the bike?
As to checking/setting timing, 58 flywheels should have a circle mark on the flywheels that indicates top dead center for the front cylinder. Pull the timing plug from the left case, rotate the engine until the front cylinder comes up on top dead center on compression stroke, and put the circle mark in the center or just to the right of center in the timing window. Adjust the timer by loosening the clamp at the base, and rotating it until the points just open. (put a zig-zag paper in the points and feel for when the points just release their grip on the paper).
That should get your timing in the ball park so the machine will start.
Good luck.
DL
aeroden
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Re: Fitting CV carb on panhead

#8

Post by aeroden »

Thanks everyone for replies. To sum it up:

1. We'll check the timing settings and readjust if necessary.
2. Can someone advise on how to check airleaks? I've red somewhere about spraying carb cleaner on joins and listen engine revving up. Is this a way?
3. Bump the idle up a little.
4.
VPH-D wrote:Are you keeping the throttle closed while using the enrichening device to prime the engine?
VPH-D
I'm just pulling <a href=https://www.deadbeatcustoms.com/s-s-enr ... s/>this</a> thingie up and start kicking. Not touching the throttle. Is this what you mean?
5. Check for slippery clutch

While my original question was about fitting CV carbs, looks like everyone here suggests that the problem is elsewhere, right?

P.S. We can only access a bike once a week, so it will take me a couple of days to come back with further finding.
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Re: Fitting CV carb on panhead

#9

Post by panhead »

Can someone advise on how to check airleaks?
Manifold Leak-Testing
aeroden
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Re: Fitting CV carb on panhead

#10

Post by aeroden »

panhead wrote:
Can someone advise on how to check airleaks?
Excellent! Thank you!
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Re: Fitting CV carb on panhead

#11

Post by lpd1snipe »

CV is a good carb but I'm using a S & S. I removed the Linkert M-74 and now running a S & S super E (bought used)on my '49 EL Pan built to '80". Running a .295 intermediate jet. and a .68 main jet. Accel pump 1 turn out. Took a while to get it initially dialed in. Cold below 60 degrees, turn on gas, full choke, open throttle 4 times. kick through twice, then find sweet spot, turn on key and kick through. Hot engine, no throttle, find sweet spot, turn on key and kick through. S & S site and YouTube has good tips too. Make sure correct heat range plugs, correct timing, good intake seals, and valve adjustment.
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