Carburetor and Fuel System
Title: 1959
FLH intake manifold clamp
Thanks,
ozwick
Post by Cotten on Mar 17, 2005, 3:56pm
Your OEM clamp was the "bowtie" type, and the fatique of decades often stretches them unevenly.
I suggest fresh clamps, but of the OEM style, or similar stainless offerings: no larger than a #10 screw for the fastener.
Please remember, the clamps were never intended to clamp the manifold, but only to crush the o-ring seals into place.
Post by ozwick on May 1, 2005, 2:58am
Have worked on my Honda carbs and intakes but this would be a first for me to replace my 59 intake O-rings and clamp replacement.
Question, is it necessary to remove the carb from the manifold in order to replace the O-rings and clamps? Or, can I just remove the carb support bracket in order to get enough slack to move/slide the manifold towards either side of the intake on the heads in order to pull the manifold out at an angle to slip the O-rings and clamps on? The 2 manuals I have do not discuss the removal or installation of the manifold. Lastly, do you put any type of sealant on the manifold gaskets where they mate up to the carb which is the stock Linkert M74B?
Thanks for all the assistance!
Post by Cotten on May 1, 2005, 3:18am
Ozwick!
The manifold assembly is contrary in enough ways to demand removing the carb.
As a "pro" (meaningless term), I always pressuretest while assembling each installation. This wards off evil spirits and warranty work.
The manifold should be put in place and then aligned to the carb on its bracket before tightening up. It is not unusual to have to 'tweak' the bracket to relieve any bind.
The pressuretest tells if you have found the 'sweet spot' or not.
I use no sealers where gasoline may foul them.
Post by ozwick on May 1, 2005, 3:35am
Cotten,
Thank you, I will now need to buy the 2 gaskets. Is there a way to check for leaks with the bike running and squirting soap water on the joints?
Thanks
Post by Cotten on May 1, 2005, 4:56am
Ozwick!
The test is performed with the carb removed from the manifold. (I do it while assembling).
You need a big cork or rubber stopper to poke a hole through for applying airpressure to the manifold: http://virtualindian.org/11techleaktest.html
Even carve a chunk of an old chair leg if you must. It IS worth the effort.
Bubbles then tell you absolutely whether there are problems or not, thus saving a lot of grief in the long run. Even test the pancover screw over each intake port, as occasionally they have been poked through. Even casting porosities show up that probably put the bike in the shed for generations.
Post by PanPal on May 2, 2005, 3:01pm
Ozwick
The easiest way I have found to install the manifold seemed to be by rolling the o rings over the manifold before putting it in position. Then roll the o rings into the gaps when you have the manifold lined up with the head ports. If you try to fit them in after you have the manifold lined up, you stand a good chance of damaging the o ring before they are squeezed to seal. Unless of coarse your heads are being installed at the same time. I line everything up with the manifold and O rings in position. Then tighten the heads and work on the manifold seal. The stock clamps are a pain to get on afterwards, but they will go in there. I still have the stock cad plated clamps on my 59. Seems they have flat spots near the riveted sections. If I weren't trying to keep it as original as possible, I'd go with a full circle style stainless clamp. They were easier to work with on my modified 50 converted to the O ring set up. If you have new O rings and everything is clean and dry, when you install them, you shouldn't need any sealer and the clamp should stay where you put them.
Post by ozwick on May 7, 2005, 5:09pm
Panpal,
Are you saying that you cannot remove the manifold with the heads installed to replace the o-rings and clamps?
Thanks
Post by caschnd1 on May 8, 2005, 9:25pm
Ozwick,
I think all that PanPal meant was that if you were installing the heads at the same time, you want to get everything lined up before tighten things down. But you can remove/install the intake with the heads already installed. I use the same trick PanPal mentioned about rolling the o-rings up on the shoulder of the manifold before installing and then rolling them back after it's in place between the heads.
-Craig
Post by ozwick on May 10, 2005, 3:29am
Thanks for the replies,
I put a couple of extra washers on the front cylinder clamp. Now I can tighten the clamp before the screw bottoms out. It seems to have done the trick for now until I pull the carb and manifold to replace the orings and clamps. I was told that another way to check for leaks was to squirt a spray of water on the manifold, this would also cause the engine to studder if a leak is detected. Anyone heard of this test before?
ozwick
Post by Cotten on May 10, 2005, 3:52am
Spraying water works, if it has dishsoap in it, and 15 psi on the mouth of the manifold itself. Then bubbles show you where every tiny leak might be .
Spraying anything on the manifold while the motor is running will only do something if the leak is really gross. And you still won't know where it is.
Post by 57pan on May 11, 2005, 2:12pm
Hey everybody - take Cotten's advice. Pressure test those manifolds. You may think your manifold is tight but you won't know it's tight until you pressure test it.
Mo was running pretty good last summer after my frame-up rebuild and I thought the manifold was tight. Last week while doing the final assembly after my transmission rebuild I decided to make a manifold tester. I got bubbles at the connection to the rear head :-/ So, I removed the clamps (2 piece split style) and found that the O-ring was actually sliced clean thru. Carefully reassembled everything with new O-rings and retested it - no bubbles ;D
Post by Mbskeam on May 12, 2005, 12:30am
hello,
57pan....
did you notice if the groove had the burr removed, at the mating halfs. when I put mine on I had to remove a burr in the groove, put a 45deg angle to it,
in the groove, so it will not slice thru the O-ring
mbskeam
Post by 57pan on May 12, 2005, 4:06am
After I took the split clamps apart I did notice that they had a burr on the edges so I took a rat-tail file to it and removed the burr.
