'93 VFR750F Carb Assembly Swap Questions

I own a '93 VFR750F that is in need of a complete carb assembly. I found a carb assembly online that is in excellent condition, for a fair price… and it's from a '92 VFR750F. From this site, I already know that the '92 and '93 VFR750F bikes use the same carb assembly….so no problem there. What I don't know is whether the seller's CA VFR750F (built specifically for sale in California, with their stricter EPA regulations) will mount properly to my NON-CA VFR750F. I'm assuming that there might be a vacuum run out to some type of smog canister, which I could easily plug. What about the overall construction of the assembly. Will the mating surfaces to the cylinder head below and the air filter housing above mate up? Will it fit properly? The seller provided ample pics of his assembly, but since my carbs are still mounted on the engine… it makes direct comparison a little difficult. I'm hoping someone on the site has technical knowledge of this potential issue.

Thanks for any help you all can provide on this.

 

Someone else might be able to be more definite than me, but normally the CA versions of a bike will use entirely identical carbs and engines, with some small modifications to meet the CARB requirements, for example the carbs will have smaller pilot jets, different air screw settings, main jets etc, engines use lower lift cams etc. All the parts from your 49-stater will be usable in the CA carbs, and the CA carbs will be identical in size/attachment points to your 49 state bike. The other emission related bits would be the PAIR system and evap canister, and if you don't have/want these you can cap off the various ports as needed.

Here's the page from the service manual with the relevant bits.

 

I have a question for YOU ! Maybe i missed the info but you have carbs on your '93 now, so why are you looking for another set ?? :confused-new:

 

I bought a donor set of carbs for my 93 as the po destroyed all the brass parts with pliers and more importantly did the cadinal sin, take the top tray with the velocity stacks off! That created a bad vacuum leak. Set i bought works good, bike does close to 150mph and eats up 135mph all day long. If you get the FSM they tell you what states and countries get what regarding jetting etc

 

Howdy Squirrel and Rider,

macdaddy's carbs are leaking fuel and he sent me an email asking about interchange--wants to buy a ready-to-go set off ebay and just swap em out to get back on the road... of course either of you guys could fix his old ones.

OT story--i was working on my ill-running-too-rich-mixture bmw k75 (fuel injection), went thru all the troubleshooting flowchart, checked all the circuits and sensors twice and still no joy, finally opened up the injection computer and a nest of fire ants came boiling out in my lap...

 

Been several days since logging back on. Wanted to give the forum a chance to add any comments. I made the decision to buy a replacement carb assembly because the gaskets on my carbs all began leaking. Once I priced out what it would cost for a complete carb kit for all 4 carbs, including all new gaskets and hoses…..it was literally almost the same amount to buy a used set in good condition. I ended up finding a set in LA that's in great shape, albeit they are from a CA bike. I had several tips sent my way on what I need to swap between the 2 setups in order to get my bike running smooth again. In the end, I'll clean up what's left….and try to recoup some of my investment by selling the leftover assembly. I'll make sure to note what it needs to have done to it….but if I can at least recover half of what i spent, then I saved money in the end. That's my plan anyway.

 

Thanks for your input. Nice to hear that someone else used the same approach. By FSM…..do you mean Field Service Manual? I do have the Honda Service Manual for the 92-93 VFR750F bikes. That should be really helpful. My replacement carb assembly arrived yesterday afternoon (Thursday), so I should be jumping into it this weekend. Thanks again for your input.

 

I did OEM bowl gaskets and float needles along with the strainer screens etc. Might have cost around $50.00 per carburetor. Good luck, my bikes run like "raped apes" :vtr2:

 

Hows your EX running? I raced a 93, and have 36,000 miles on my 04 with a rolling complete parts bike with 500 miles on it. :loco: Its my commuter bike, does 120 mph at 10,000 RPM - but I try to keep it at 8-9000 RPM.

 

Yes,….I looked into that as well. So between the 4 carbs I was looking at $200. However, I had leaking fuel from every single rubber component…. not just the gaskets on each respective carb. It was my fault….and now I am paying the piper for my actions. Basically, I bought the '93 VFR750F… and after 7 tanks of gas realized that I had partially clogged jets. I followed all other leads (possible bad thermostat, possible stuck choke, etc.), but the only thing that panned out in the end was clogged jets. I contacted the seller….and in that conversation he finally admitted that he had not ridden the bike for 18-20 months. It just sat in the garage. After jumping on VFRWorld and reading for hours….I decided on using Sea Foam. Went thru 3 cans of it in recommended doses……and NOTHING. Still getting exactly 25 mpg on each tank. At fill-up…..the tank was as full as I could get it….and I'd ride it until I had to switch over to reserve fuel. The bike was getting half the mpg that it should be getting. That's when…..out of total frustration and anger… I decided to up the anty by using BG Chemtool. I'd similar to Sea Foam, except a lot stronger. I ran thru almost the entire tank, and the next day we had a heavy snowfall. That's where I made my mistake. Between work and winter chores…..I forgot to drain the gas out of the bike's tank, fuel hoses and carbs. That BG Chemtool sat in there all winter….and by Spring I had leaking fuel everywhere. So,…..now I just want to replace the entire assembly…. and learn from the mistake I made. A new fuel pump was only $20 on Ebay…. but I am finding trouble locating new fuel hoses that run from the tank's petcock back to the fuel pump…..and then from the fuel pump to the carb assembly. I don't want to perform all this work, only to find out I'm leaking fuel in the area of the fuel pump…under the seat…..with electrical wiring very close (rear blinkers, tail light, fuel pump wiring, etc.). A lot of damage from that 1 can of BG Chemtool. I did, however, have a very enjoyable afternoon at the local rifle range,…..where I pumped approx 50 rounds of ammo into that empty can of BG Chemtool.

 

My EX500 runs great. This bike I picked up for $850……came with a custom paint job…..Muzzy performance exhaust…..nice helmet that comes pretty close to the color of the bike….and an awesome white and black sport bike motorcycle jacket (with the kevlar pads on shoulders, spine, elbows, kidneys. etc.). He just threw that in at the last minute…..along with a lighter weight black and red bike jacket. Also tossed in a Haynes manual on the EX500 bikes. Also tossed in all the docs and box from the jet kit he installed, which had the original jets inside. It was the best deal I've ever gotten on a bike. I thought the 500cc would be a little small for me….but that Muzzy pipe makes that bike roar. Love that pipe! I'll try to post pics of both bikes sometime this weekend.

 

BG sells good stuff not available to general public, used their stuff with good success. When you take your carbuertors off, invest in a new tstat with o ring. Just makessense. Peace

 

You can find those fuel hoses new or get them from ebay. I paid $1500 for my EX in 2007, it had 1500 miles on it. Parts bike I got for free.