Found a 93 thats not too far away and have some questions

I am really hoping that things come together on a 93 that I found and I end up bringing it home. There are a coupe of questions I have and need verification on. I am pretty sure I have read that a 4th gen exhaust will not fit a 3rd gen if the 3rd gen has the centerstand. Is this a for sure thing as I would really like to put a 4th gen exhaust on the bike, but I don't want to get rid of the centerstand.

The other question involves the carbs. I am thinking there may be some advantage to swapping a set of 4th gen carbs on to the bike. Would I also have to use the 4th gen airbox or would the 3rd gen airbox work on the 4th gen carbs? What are the differences in the airboxes?
Has anyone put the newer set of carbs on their 3rd gen and if so, what did you realize out of the change?

Lot of questions I know. Thanks for any and all info.

Jeff

 

I think that the 4th gen headers fit the 3rd gen with a centerstand but there's no center stand stop to keep if from folding further up and hitting the chain. As for the carbs, if you swap carbs, I believe the ECU should be swapped too. from a fitment stand point it swaps no problems as do the air boxes. From function stand point, I would think the best results come from a paired ECU.

 

What does the ECU have to do with the Carbs? Maybe I'm missing something but an ECU on a carb bike functions with spark but has nothing to do with air/fuel mixture.

To the OP, I'd say get the bike and see how you like it the way it is first. Then decide what mods you'd like most. I can tell you as a '93 VFR owner, your not going to find much more power in fuel or exhaust mods. Suspension and brake mods are better money spent. Couple that with a good racing school or track school and you will find that 90% of what makes the bike fast is the riders technique.

Either way, have fun.

 

The 3rd gen carbs use round slides and have a larger venturi than the 4th which uses flat slides. You may need to swap the throttle cables with the carbs too because they use different lengths and connect to different carb pulleys, 4th (carb 2) are longer than 3rd (carb 1).

 

Holy crap, I spent most of last night welding and test fitting my exhaust for my rebuild project. Between poor ventilation and the exhaust fumes, I think I must have had a stroke. I was just reading what I wrote last night and this morning. I was COMPLETELY thinking about CAMS not carbs in reference to the ECU. to the OP, DISREGARD the ECU stuff. I guess I'll be spending today out side getting some fresh air.

 

Ah!! That makes more sense to me. I'm not one to be a know it all and I'm always trying to keep an open mind and learn more but the carbs and ecu thing got me confused after I read it a few times. Thanks for clarifying.

 

OK, if you use the 4th gen exhaust on a 3rd gen, you WILL lose the centerstand.

Personally, I always liked the 3rd gen exhaust. That collector under the engine adds significantly to the torque curve. The 4th gen is angled more towards top end power. Fabbing a new exhaust can for the 3rd gen is easy too.

Besides, centerstands were an OPTION on 3rd gens. If you have one, keep it.

Larry

 

I was thinking of losing some weight with the 4th gen exhaust, but I am a big fan of torque where you need it most. More up top isn't a big deal with me. I want the power and torque where I use it most of the time. That was my thinking with the carbs too. From what I have read it seems the 4th gens get better mileage and I like that especially with the smaller tank on the 3rd gen. I can't find any differences except for the carbs and pipes. If the ecu is different then that could be some of it too. Has anyone swapped the 4th gen ecu onto a 3rd gen and what were the results?

Jeff

 

Crap, hope I didn't start a whole "ECU" envy issue...

anyway, I don't know how much weight you would lose with the 4th gen headers. All the weight loss would likely come from removing the centerstand. I'd fab up an aftermarket can to your 3rd gen coupler for some weight loss.

As for carbs, I do believe the 4th gen carbs were meant for better low/mid range response. Having said that, I haven't ridden a 3rd and 4th back to back to tell how much difference it really makes. So far, my 3rd gen pull pretty decently without taking the rpm's much beyond 8000. As mentioned befor, you could see how you like the stock set up and go from there.