Hex Bar Linkage

[71Chucky]

Hello Peoples,
I was just wondering if any of you clever people could help me out with this problem.
I had a 1776 engine installed in my van early last year with twin weber 40IDF carbs and a Hex Bar Linkage supplied by CSP. The engine was run-in with no problems whatsoever, until approximately a few hundred miles later the engine kept racing when idling whilst hot. I noticed the hex bar linkage wasn’t snapping the carbs closed all the way. I returned the van to the garage that fitted it and they decided it was a problem with the carbs, so they swapped the carbs out and this seemed to solve the problem. I hadn’t really used the van as much as I would have liked this year but on the way to Busfest the same problem returned (engine gets hot, engine starts to race, carbs not closing fully). I understand you can purchase a stronger return spring for the Bell Crank Version from CSP but can you purchase something similar for the Hex Bar Linkage. I also had a Buttys Bits accelerator assembly fitted with the new engine , so I’m pretty sure that’s not the cause.
Any help would really be appreciated.
Thanks in advance,Lee.

 

[K@rlos]

The carbs idle speed should be set when the engine is up to temp. The CSP hex bar is supplied with a stout return spring, an extra 1 is not required. Check the cable isn’t adjusted too tight and that you don’t have any air leaks on the inlet gaskets

 

[Clem]

On mine I have a Buttys kit fitted but also a stout spring the mounted to the engine bay roof. Possibly overkill but does the job.

As Karlos said, ensure it’s correctly adjusted at temp. Don’t be tempted to run it too loose. I can vouch for how annoying it is when they drop off on the motorway …

 

[K@rlos]

Is your garage clued up with carbs & old cars? I suspect they were throwing darts if they replaced the carbs to sort that, did they say what was wrong with them? Sounds like an installation/tuning issue to me.

 

[Ben72Bay]

Hello Peoples,
I was just wondering if any of you clever people could help me out with this problem.
I had a 1776 engine installed in my van early last year with twin weber 40IDF carbs and a Hex Bar Linkage supplied by CSP. The engine was run-in with no problems whatsoever, until approximately a few hundred miles later the engine kept racing when idling whilst hot. I noticed the hex bar linkage wasn’t snapping the carbs closed all the way. I returned the van to the garage that fitted it and they decided it was a problem with the carbs, so they swapped the carbs out and this seemed to solve the problem. I hadn’t really used the van as much as I would have liked this year but on the way to Busfest the same problem returned (engine gets hot, engine starts to race, carbs not closing fully). I understand you can purchase a stronger return spring for the Bell Crank Version from CSP but can you purchase something similar for the Hex Bar Linkage. I also had a Buttys Bits accelerator assembly fitted with the new engine , so I’m pretty sure that’s not the cause.
Any help would really be appreciated.
Thanks in advance,Lee.

Hi @71Chucky! Who installed your engine? I have a similar spec if you need any pics

 

[71Chucky]

The carbs idle speed should be set when the engine is up to temp. The CSP hex bar is supplied with a stout return spring, an extra 1 is not required. Check the cable isn’t adjusted too tight and that you don’t have any air leaks on the inlet gaskets

On mine I have a Buttys kit fitted but also a stout spring the mounted to the engine bay roof. Possibly overkill but does the job.

As Karlos said, ensure it’s correctly adjusted at temp. Don’t be tempted to run it too loose. I can vouch for how annoying it is when they drop off on the motorway …

Morning Gents, thanks for your responses and I will have a look at the cable adjustment, with regards to the cable would it make a difference to the engine racing when the engine gets hot. I just assumed if it was a cable problem the Hex Bar wouldn’t be snapping closed when cold as well.

 

[71Chucky]

Is your garage clued up with carbs & old cars? I suspect they were throwing darts if they replaced the carbs to sort that, did they say what was wrong with them? Sounds like an installation/tuning issue to me.

Hello Karlos, the garage is a VW air cooled specialist and as been around since the 80s,so they know their stuff . When they swapped the carbs out he told me he’d found some scoring in the carbs, which was causing the problem.with regards the tuning the engine sounds and runs sweetly when cold and normal operating temperature, it just randomly starts racing when the engine is idling when hot. I can literally walk back to the engine and manually push the Hex Bar closed onto the carbs.obviously the engine racing then stops, touch the accelerator again, same thing happens. Really sorry for the essay but I just wanted to be clear. ( also forgot to mention your dealing with a complete thicko when it comes to mechanics, so pretty much everything is above my skill set)
Once again thank you for your responses.

 

[71Chucky]

Hi @71Chucky! Who installed your engine? I have a similar spec if you need any pics

Hello Ben, thanks for your reply. This is my engine bay I’m assuming it’s similar to yours . I hope you can get the gist of the setup from my picture. The garage who installed the engine is an air cooled specialist based in Hampshire. I haven’t lost faith in them yet, but I thought I’d just ask on the forum first before I contact them.
Cheers Lee

 

[62 deluxe]

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[62 deluxe]

I’ve always run extra springs with my hex bar on my bug. This shows them clearly

 

[K@rlos]

Hello Karlos, the garage is a VW air cooled specialist and as been around since the 80s,so they know their stuff . When they swapped the carbs out he told me he’d found some scoring in the carbs, which was causing the problem.with regards the tuning the engine sounds and runs sweetly when cold and normal operating temperature, it just randomly starts racing when the engine is idling when hot. I can literally walk back to the engine and manually push the Hex Bar closed onto the carbs.obviously the engine racing then stops, touch the accelerator again, same thing happens. Really sorry for the essay but I just wanted to be clear. ( also forgot to mention your dealing with a complete thicko when it comes to mechanics, so pretty much everything is above my skill set)
Once again thank you for your responses.

100% a tuning/set up issue. As I said before the CSP hex bar has a very good return spring and an extra 1 is not required.

 

[K@rlos]

I’ve always run extra springs with my hex bar on my bug. This shows them clearly

You don’t need to on the CSP version, they have addressed this unlike CB & Empi.

 

[K@rlos]

Morning Gents, thanks for your responses and I will have a look at the cable adjustment, with regards to the cable would it make a difference to the engine racing when the engine gets hot. I just assumed if it was a cable problem the Hex Bar wouldn’t be snapping closed when cold as well.

Yes it will affect it when hot, if you set it up when cold everything will expand, move and be thrown out of adjustment once up to temp. Always do the tuning and adjustments on a hot engine. Get engine hot and undo the cable clamp to see if it still races.

 

[Clem]

First port of call for me, given your description now, would be to adjust the hex bar mount points. I think they have either been over tightened or the lock bolts not secured allowing them to tighten. Slacken then off a tad , ensure they are lubed, and see what happens. It’s a free try and will take minutes. I think they may be tightening up when hot.

 

[62 deluxe]

You don’t need to on the CSP version, they have addressed this unlike CB & Empi.

Haha, my linkage is so old it’s stamped Claude’s Buggies, it needs all the help it can get!

 

[Ben72Bay]

Hello Ben, thanks for your reply. This is my engine bay I’m assuming it’s similar to yours . I hope you can get the gist of the setup from my picture. The garage who installed the engine is an air cooled specialist based in Hampshire. I haven’t lost faith in them yet, but I thought I’d just ask on the forum first before I contact them.
Cheers Lee

Similar!

 

[mike202]

Just as a matter of interest for you, I have the CSP bell crank linkage and had similar problems with the engine racing at junctions etc. I found out that the linkage is not supplied with a spring. The buttys bits throttle spring and the carb springs ( very small Weber 34 ICT) wasn’t enough to return the carbs to idle when the engine was warmed up. I got a CSP spring made for the linkage which goes inside the bell crank part, and this cured all problems.

 

[K@rlos]

Just as a matter of interest for you, I have the CSP bell crank linkage and had similar problems with the engine racing at junctions etc. I found out that the linkage is not supplied with a spring. The buttys bits throttle spring and the carb springs ( very small Weber 34 ICT) wasn’t enough to return the carbs to idle when the engine was warmed up. I got a CSP spring made for the linkage which goes inside the bell crank part, and this cured all problems.

He’s got the CSP hex bar, not the bellcrank. The hex is supplied with a spring, CSP do now sell a spring for the bell crank as the carbs returns were not substantial enough alone.

 

[gagvanman]

The Hex bar setup has nylon bearings at each end, also I think there is an adjustment for the end float of the bar. Check that this isn't too tight because when the engine compartment heats up it could be binding.

 

[warrenstuart]

I had a new 1776 with twin Weber 40 IDF carbs using CSP bell crank linkage and had exactly the same issues.
There were a couple of problems…
Initially as the engine loosened after a few hundred miles the idle speed increased so I had to back it off on 2 separate occasions then it settled.
I also had racing on gear changes because the throttles weren’t returning to the stop due to no spring on the bell crank linkage so ordered one from Eurocarb. Whilst fitting the spring I also found the linkage from the bell crank to one of the carbs hadn’t been adjusted correctly so the ball joint at the bell crank end was twisted hard one way and at the carb end twisted hard the other way making it stiff to move and hence not allowed the throttle to easily return to the idle position so I loosened the one end of the bar and twisted the ball joint just enough so that both ends cantered up and now it moves freely. This was only a very small adjustment so didn’t effect the balancing of the carbs.
Hope some of that helps