Honda Pan European - 1996 ST1100T Standard
Carburretor Synchronisation
Easy job this. But you need two long handled cross head screwdrivers to reach the adjusting screws. And a torch. And another screwdriver to move aside the rubber curtain behind the cylinder heads and in front of the carburettors. And a third hand - but a torch that you can hold in your mouth does just as well.

I use a Morgan Carb Tune II - which is great - but I've just recently discovered that the four columns do not give the same reading ! So I found two that did and use these as a final reference.

Received wisdom is that some sources for the procedure for balancing the carbs is incorrect. Apparently the correct information is that other 3 carbs can all be matched independently to the base carb (rear left). But I have only seen this in the Honda Common Service Manual, and the ST1100 manual that I have is not specific about the correct procedure.

On my first ST1100, one of the adjusting screws for the right hand bank had an effect on both carbs - as one went up, the other went down. Getting it right was a bit of a balancing act between the two adjusting screws. Small movements. But the method of balancing left side to each other, right side to each other and then left pair to right pair as described in the manual that I had, doesn't work either.

I can only guess that something somwhere in the mechansim was sticking. But I did take the carbs off and check everything over. I really don't recommend this approach though. I'm still confused. I always managed to get it balanced, but what happened in practice bore no relation to what the manual said, or what other people have told me.

I never needed to balance the carbs on my 2nd ST1100. It stayed silky smooth until I sold it at 70,000 miles

If you take too long over it, the engine gets hot and it becomes almost impossible to get right. The local Honda mechanic told me, if you don't get it sorted within a couple of minutes, turn the engine off and leave it. Come back to it later.

Now - don't forget the surgeons final check after this process. With screwdrivers and torches poking in between the frame and the engine, it is easy to leave one in there. Count them ! Having a screwdriver jamming the carbs open doesn't really bear thinking about.

So that's where my other screwdriver went.

If anyone else has a similar problem with the RH carbs I'd be interested to know. If you don't - I'd be even more interested. Drop me a line here.


One of the main problems I had recently was that the Carbtune was not registering the vacuum properly. It doesn't tell you this in the manual, but after much pratting around with lengths of tube and large hyperdermic syringes (minus the needles), I discovered that the tubes were not forming a 100% air-tight fit around the connectors. A similar thing was happening at the carb take-off point. The readings were altering as I moved the Carbtune unit. Not by much and it was impossible to tell reading the levels - except that the bike didn't sound 'sweet'.

I cured this by using cable ties clamped tightly around the tubes on the unit. wooden clothes pegs provided just enough pressure around the tubes at the carb end.

Normally when I say I'm going to tinker with the bike for an hour, Lynne just looks at me and laughs. She did this time too. But it took me 45 minutes to remove the necessary plastic (dummy tank, wind deflectors and rocker box faring panels); balance the carbs and put everything back again).

 

These pages relate to my first bike after a 17 year lay-off. Bought in 2000 with 28,000 miles on the clock. Traded in for a 2000AY version in Sep 2003 with 60,000 miles on the clock. The pages were intended to provide information to a prospective buyer, but are maintained here as information for anyone who may be interested.

Website 2011 JFHeath