Accelerator Cable for Dual Carbs ? Options

[cary]

In putting Mark's engine back in and replacing the broken accelerator cable. It seems the cable isn't quite long enough to work/fit correctly. In the FI arrangement the cable crosses the engine at 45 degrees. In dual carbs it needs to come at the bar at 90 degrees. Which pulls the bowden out of the firewall. Which will allow water down the cable tube.

What have others done to work around this ?

[rfinegan]

Take a look by the pedal cluster and the pivot for the accelerator cable/clevis mine had the cable drop down(loop) under a bolt making the cable seem to short.. When I routed the cable correctly all was good. May not be what you are asking but took me a few hours to resolve my issue when I reconfigured my Tangerine linkages. It should have just bolted up again and was just to short


-Robert

[somd914]

Take a look by the pedal cluster and the pivot for the accelerator cable/clevis mine had the cable drop down(loop) under a bolt making the cable seem to short.. When I routed the cable correctly all was good. May not be what you are asking but took me a few hours to resolve my issue when I reconfigured my Tangerine linkages. It should have just bolted up again and was just to short


-Robert

I've used both hex bar and CSP bell crank systems with stock cables. Not sure what to tell you, perhaps rfinegan is onto something.

[rhodyguy]

Is the linkage on the rear of the carbs?

[cary]

Cable itself is long enough. But when I use the accelerator cable hole in the engine tin the bowden portion is too short to both bolt up to the cable mount on the engine and stay in the cable tube on the fire wall.

I was pondering relocating a different hole in the engine tin.

[somd914]

Cable itself is long enough. But when I use the accelerator cable hole in the engine tin the bowden portion is too short to both bolt up to the cable mount on the engine and stay in the cable tube on the fire wall.

I was pondering relocating a different hole in the engine tin.

You got me thinking since it's been a few years, so I took a look... I routed my cable up between the tin and firewall then secured it, thus it fits through the rubber gasket around the engine bay seal.

[cary]

Is the linkage on the rear of the carbs?

I'll shoot a couple pictures this after noon.

Here's what I originally found. Broken because it was too short. Held straight with a conglomeration of zip ties. This is the only picture I have.
Snapped the threaded tube in half.



This ones being replaced. I don't want the same thing to happen to the new one.
So I'm going to add a locknut (like MarkV) to weak portion right against the bowden end to give it more strength. Should solve the problem.

[cary]

Cable itself is long enough. But when I use the accelerator cable hole in the engine tin the bowden portion is too short to both bolt up to the cable mount on the engine and stay in the cable tube on the fire wall.

I was pondering relocating a different hole in the engine tin.

You got me thinking since it's been a few years, so I took a look... I routed my cable up between the tin and firewall then secured it, thus it fits through the rubber gasket around the engine bay seal.

I'm was thinking thats would be the BTDT work around. I think I'll go that direction too.

[rhodyguy]

I don't recall the inner sheath sticking out that far. Is this a new cable? I've always used the factory cable routing and tin grommet for the cable. When I had a triad linkage, the cable holder arm/bracket was at roughly the same height as the crossbar connection point. Never had to use 5 zip ties to keep it in place either.

[cary]

That ones in the garbage can. Busted and the barrel nut was stripped out.

[MarkV]

My set up might be different because of the a/c compressor. There is plenty of slack to move the cable up and down a couple of inches.

[cary]

That's where it needs to come from. That will give you the 3-4 inches of slack to get it dressed in there correctly.

Thanks ..........

[SA-914]

This is what I have so far. But the pedal feels like it's in a bind.

[Darren C]

WTF


SA-914 That bellcrank linkage geometry is ALL WRONG. Throw it in the trash!!

It's no wonder your having problems with cable length, the mount bracket is god awful and all wrong.
The binding is also because your running the cable out of stock lay-out.

The angle is completely wrong on the cable connection bracket and the arm doesn't look the right length either.

Throw it in the trash and make a new one, it will make a dog of a driving experience if left like that.

I've just posted a "bonus" how to. It's in my Build-off Challenge thread here:

http://www.914world.com/bbs2/index.php?sho...p;#entry2341877

(there's no point telling a guy to throw something in the trash if you can't help him sort out the problem!)

[somd914]

Looks like SA914 is running a CSP linkage system. Agree the cable mount is a bit questionable, and the bell crank geometry looks askew, but I wouldn't say throw it away, lots of us run CSP's linkage with no issues - personally I like the feel of my pedal more with dual carbs and CSP linkage than with stock D-Jet.

As for properly installing a CSP system, take a look at this:

http://www.csp-shop.com/technik/pdf/deeng/23951.pdf

[SA-914]

Somd914-you got any pics of your installed system? I'm running 40idf carbs. When I follow the 50% throttle rule and line ub with the case, it looks like my arms may be a bit short.

[Darren C]

From reading the installation manual somd914 kindly posted, your CSP linkage was designed to be used with their throttle arms on the carbs too !!! (why do this? it's more work for CSP to make arms for the carbs? why not make the bellcrank fit Weber arms? This is a common sense issue, "KISS" Keep it simple stupid! Using standard Weber arms on your carbs make its more universal, easier to install and removes additional manufacturing costs and reduces purchase price)
SA-914, your centre bellcrank arm will be too short on travel if you haven't got the CSP arms on your carbs too.
I can't understand why CSP made the carb levers shorter? and the bellcrank with shorter arms? this reduces mechanical advantage/leverage and makes for a larger force to operate putting extra strain on the cable and more force at your foot.

Anyways the CSP linkage is made for a throttle cable that runs in line with the crankcase join (front to back) Here lies its achilles heel. (running the cable away from stock layout causes length and binding issues)

My advice is to make a new bellcrank with the main cross arm that connects to the carbs set at 45 degress with carbs on throttle stop. (you'll need to adjust the rods to suit, may need shortening or lengthening) Then make the new bell crank arm for the throttle cable to sit at the correct angle to pull from the "stock" cable position.

You can probably retain the CSP mounting and vertical pivot, but you'll need to make a new cable mounting and bellcrank to get it right.

[somd914]

I can post a few pics tonight.

But for keeping it simple, I can say it didn't take long to install, perhaps an hour, I've been running it for three years, it has a much better feel than the old hex bar, and certainly is easier to synch carbs with than the hex bar. Seems simple enough to me.

[Darren C]

The KISS comment is aimed at CSP for bringing to market a product lacking 914 application or basic engineering forethought.

Don't even get me started on the empi/crossbar type linkage!

All these carb conversion linkages really are "the emperor's new clothes".

I've yet to see a properly engineered 914 carb conversion linkage for sale.

[dcecc1968]

When I switched to dual webers with hexbar and replaced my accelerator cable, the collective wisdom on 914 World agreed:
1) Don't use the hex bar, you'll never get your carbs synched right.

2) If you use the hex bar, you'll need to run the accelerator cable between the firewall and the engine tin and not the hole in the engine tin because the engines were never designed to have carbs.

3) If you choose option #2..... after you get frustrated from not being able to sync your carbs, contact Tangerine Racing and get Chris' cable system.

I'm still on option #2..... not frustrated enough yet, I guess.

Good luck.