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94 carbs in a 90/91 F-L

Old 12-24-2010, 06:01 AM
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Default 94 carbs in a 90/91 F-L

Hello, I'm new to the forum - lots of useful information here. I'll contribute to technical threads in the future, but the first "contribution" is a couple of questions...

Has anybody here actually made the later (94) carb swap into an earlier bike? From what I can tell trawling the web, the later carbs improve mid-range, which is always good. I can pick up a set of the newer ones quite cheaply, but before I lay out the cash I was hoping somebody could say whether it's worth it or not. For instance, do they fit the existing F-L airbox? Do the F-L throttle cables just plug into the newer fittings? Do they actually make a difference in the real world?

I know the newer carbs have a different balance method with different vacuum take-offs, but I can't tell if Honda moved them to the block or just relocated them to the underside of the newer carbs.

Secondly, has anyone replaced the stock airbox with individual filters? Looks like it can be done using the vast K&N range and their excellent "search by dimension" web guide, but again, the outlay on jet kits and time spent may not be worth it.

I don't want to change the smooth character of the bike, just want a little bit more out of it.

I have two F-Ls and a nice new lightweight 4-2-1 from Sandy's Bike Spares to play with, so I will be posting how this all goes in the next month or so. If it ever gets above freezing here again!

Anyway, any practical advice would be appreciated and as I said, I'll be putting a guide together, hopefully with photos, to help others do the same.

Many thanks from Manchester, UK.
Old 12-26-2010, 11:56 AM
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I looked into the same thing. From what I can tell the heads were the exact same for all the years. You need to change the rubber boots that connect the carbs to the head. I may have an extra pair if you give it a try so let me know. The airbox needs to be changed as well. I don't know if this will force you to change the side plastics as well. I am considering the same change so I will be following along. Good luck and keep us posted.
Old 12-29-2010, 10:48 AM
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Thanks for the response. I'll check whether the seller has the engine-side boots. He might have the airbox too.

It looks like the two model years had the same side panels, as the facelift seems to be only at the front (turn-signal locations) and the tail. If that's the case, the snorkels from the later airbox should be in the right place to meet the openings. Still don't know about the throttle and choke cables. It's going to be a suck-it-and-see job.

Anyway, as the weather is improving to merely miserable in the next few days, first up is the exhaust swap out from stock 4-2-1-2 to the Sandy's 4-2-1. Fingers crossed that the 20 year old exhaust studs come out cleanly. Here we go...

At least we're not under two feet of snow in NJ! I lived in Philly for twenty years, and I remember what that was like.
Old 01-06-2013, 08:21 PM
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well how did it turn out?
Old 03-23-2013, 05:03 PM
Join Date: Oct 2006
Location: Cambridge, UK
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I did just that swap - a set of the later carbs (with black plastic tops) fitted to a 1990 FL. The change needed a change of cylinder head (the vacuum take off for the fuel tap comes direct from the head on the later models), a change of airbox (the earlier one won't fit the carbs), new throttle cables, new choke cable, err, and I think that's it. It did make a difference to the power output in the mid range, but then, my old carbs were worn and leaking air. Good luck with your change.
Old 03-24-2013, 03:09 PM
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It's been parked up for over year now. In the meantime I bought and fettled a Blackbird (I'm over on CBRXX under different name), so I was distracted! I had cleaned the original carbs to a fare-thee-well but found that the problem was actually the brass bushings in the carb assembly, which had worn oval. They couldn't be balanced. I managed to get a reasonably decent set out of the two carb sets I had and it's alrightish. But I have to say that the whole experience just put me off carbs forever - hence the FI BB - or so I thought anyway.

Fast forward to now, and I've moved to London and have a job which will allow me, when this bloody weather sorts itself out, to park the BB down here in a locked-up car park, that will clear the space in the workshop back in Manchester to bring back the 1000F from storage so I can finish her. Which I really want to do now. So a dead thread is brought back to life.

Don't want to change the head, but there must be a way around that. The rest sounds more-or-less straightforward.

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