94 cbr600 f3 engine in it with f2 carbs. I have good spark and have sprayed starter fluid in it but haven't gotten it to fire. Any ideas? Compression would be the next idea. Is there a port for a sensor or something I didn't block?

I remember reading that there was something that needed to be blocked where the f3 carbs connected to the engine. Any ideas on that?

 

So tinkering with it today made sure the carb boots were tight and tried starting again. After cranking it over I could hear a leak type sound. Maybe from a hose or carb boot? Tried spraying starter fluid around the boots while cranking it but nothing.
Can anyone tell me what hoses to where and which ones are blocked so I can double check?

 

I personally have never worked on an F3... just the F2, when it comes to the old Honda 600's, so, my knowledge on the F3 carbs is limited.
What I do know about the F3 carbs, is that the main jets for cylinders 2 and 3 are larger (138) than for 1 and 4 (135), whereas the F2 carbs are stock with 135 in all four. Also, the slow jet is larger (40), than on the F2 (38).
I'm not sure if there are any glaring issues with F2 carbs on the F3 motor - I'm not even certain if the throat (venturi) is the same size betwee the two or not, but you might be running too lean with the F2 carbs on the F3 motor, especially if you're running a "hi flow" aftermarket air filter, like a K&N, BMI, or UNI.

As far as a port that might need blocking, I'm assuming you're talking about some sort of vacuum port, or maybe emissions hose, on the motor, and for that info, you'd probably be better served by also posing this question in the F3 section, if you haven't already.

 

By the way, another forum member recently learned that he had the opposite of your setup - an F2 motor with F3 carbs, and has since bought F2 carbs for his - I'm thinking maybe you should try and ****** those F3 carbs from him, and get those on the F3 motor where they belong, that is, if it is possible to do so... is the airbox you have from an F2 or F3? Anyway, check this thread:

my $500 94 f2

 

As far as ice read its been said to use the f2 carbs for the f3 due to an electronic piece on the carbs that won't plug in to the f2 harness