After many tries and re-jetting the CV carb on my 89 FLHTC without any sucess, I gave up and bought a Mukuni Easy kit.
When installing it today, I did have to trim a little off each fin to fit and rerouted the stock cables but when it came to fitting the carb onto the seal ring on the intake manifold, try as I may it would not go even heavily lubed. After resorting to a block of wood and hammer ( which I have done before with the CV ) it would not fit, tearing the rubber seal ring in the process.
I have measured the inside and outside diameter of both the Mukuni and the old CV -and both are identical.
I wondered if having the CV carb on my bike as an 89 model ( I read that the CV were fitted from 90 on ) if the manifold was stock or had been swapped out but even then are the manifolds across those years not identical?.
Would appreciate any and all thoughts here, as I feel I am losing the plot with this one.

 

I never had a problem with putting a 42 in a stock CV spigot manifold. Perhaps you should try another seal as both measure the same. The CV came off so the Mikuni should go on. Try using dish soap instead of grease as some petroleum based lubes can swell the rubber.
John

 

Both carbs are a TIGHT fit on the manifold seal, and take a lot of soap and persuasion to seat. I've seen people running carbs on Evos without air cleaner support brackets, just relying on the tight fit of the rubber seal to hold the carb and air cleaner in place. It's not right, and you shouldn't do it, but I HAVE seen it.

 

Appreciate the suggestions. Got new seal, liberally coated with WD 40 and it went on. Bike started up and now runs perfectly.