Guest coffeebrake Posted October 12, 2012 Share Posted October 12, 2012 I did a search but didn't find this answer. I've got a line on a known good VFR750 engine. Will it fit into my VFR700 frame? I know the carbs are different, this 750 engine would have the carbs with it. And, how much of a difference would that make? Is the "uncorked" 750 a much faster machine than the 700? I'm in a quandary: I'm a quasi-experienced rider looking to become faster and smoother in the twisties, but the modern sportbikes leave me cold. The old V4 in my 700F moves my soul like few other machines ever have. It cruises at 50+ mpg and I can work on it myself pretty easily. Besides, I already have two in-line fours, the Bandit 1200 and the Concours 1000, so I'm not too keen on giving up my VFR for an in-line four sport bike. Gas mileage, affordability, and being able to work on it myself are also major considerations. I'm considering if it is possible to update the VFR into the fine-handling, fine-braking machine I want now. I know Jamie Daugherty can bring the suspension up to date, and I'm looking into the CBR wheel swap. That leaves me with my lack-luster brakes, which I'm still researching. And all this is going to cost quite a bit, but still less than a newer GSXR750 or Ninja 636. It's not more power I want right now, it's handling. The VFR revs up and has great torque exactly where I want it, but the brakes and suspension and bias ply tires are holding me down. Well, and its ponderous weight, but there's no way around that. I can accept that it's heavy. If I did these things, would I find myself with a near-hundred-horsepower bike that handles well and makes me smile? Would I find myself able to move more smoothly and quickly in the twisties confidently on new suspension and rubber, or would I still feel like I was at the end of bike's capabilities? Your opinions are much valued, please share! Link to comment Share on other sites More sharing options...
Member Contributer gll429 Posted October 12, 2012 Member Contributer Share Posted October 12, 2012 what year 750 are you talking about? forget the 84 or 85. the 3rd gen motor MAY fit...no clue.. .honestly.. its not THAT much of a boost over the 700.. get your suspension set up..and some newer wheels and tires. and it will make a HUGE difference.. you you may actually find your yourself going faster by having the bike set up correctly. Link to comment Share on other sites More sharing options...
Member Contributer gll429 Posted October 12, 2012 Member Contributer Share Posted October 12, 2012 by the way.. you can also use gsxr wheels. i put some katana wheels on few VFRs ans 2 cbr 600s from the late 80s Link to comment Share on other sites More sharing options...
Guest Posted October 12, 2012 Share Posted October 12, 2012 Oops, I wasn't clear. I own a 86 VFR700F and was considering putting a 86 VFR750 engine. Link to comment Share on other sites More sharing options...
Member Contributer Burns Posted October 12, 2012 Member Contributer Share Posted October 12, 2012 if it's an 86 motor (RC24), it'll slot right in.. they didn't import the 750 in 87, I don't believe. US didn't get 88/89.. pretty sure the 90 and on motors were complete redesigns, so who know's what modifications would be required. there shouldn't be that much of a HP/torque difference. The only reason for the 700's were to beat tariffs. Link to comment Share on other sites More sharing options...
Member Contributer airwalk Posted October 12, 2012 Member Contributer Share Posted October 12, 2012 if the 700 motor is sound you're probably not going to be gaining enough to justify the trouble of changing to a 750, work on handling mods instead. however, if it needs a motor by all means try to use a 750, they're not so numerous so grab a good one if you get the chance. Link to comment Share on other sites More sharing options...
Member Contributer mk2davis Posted October 12, 2012 Member Contributer Share Posted October 12, 2012 I have no experience on a 700, but I've heard there is little difference in quickness because the of the gearing (the 700 either gains one tooth in the back or loses one in the front, I don't remember which). So it sounds like RPM's will drop by a few on the hwy, and slightly higher top speed. I'm not sure how important these two things are to you. If it were me, I'd focus on handling. It sounds like that is most important to you, and I'm not sure the work is worth an extra 6(?) hp. Link to comment Share on other sites More sharing options...
Guest Posted October 12, 2012 Share Posted October 12, 2012 OK then I'll skip on the motor swap. I'm two old Hondas to rebuild and sell (Rebel 450 and another CX500) away from making the VFR handle like new! Link to comment Share on other sites More sharing options...
Guest Posted October 14, 2012 Share Posted October 14, 2012 So...rear shock upgrade, about $400 Are cartridge emulators available for the front? Looks like a set of CBR wheels (or others that can fit) would run upwards of $300 and likely need new rubber. And new bearings. My swingarm pivot is sloppy, that needs to be replaced too. I don't know anything about the radial brake master cylinders, or how much they run. I think my rotors are warped too. They drag for half of the wheel's revolution when I'm pushing the bike. What else goes on the wish list? Link to comment Share on other sites More sharing options...
Guest Posted October 14, 2012 Share Posted October 14, 2012 by the way.. you can also use gsxr wheels. i put some katana wheels on few VFRs ans 2 cbr 600s from the late 80s Do you have a link to the posts about this process? I'm not particular to CBR wheels. I don't even care if they match. I just want to run modern rubber front and rear without having to walk on water to make it fit. Link to comment Share on other sites More sharing options...
577nitroexpress Posted November 10, 2012 Share Posted November 10, 2012 I have to reply here, I'm in the process of upgrading my 86 700, full shebang engine to a 750 with Dave dodge port polish, race cams, kerker 4 x 2 x 1. F2 wheels, fox twin clicker rear shock, gold valve emulators with progressive springs, fork brace. Bike is mint, 12500 original miles, so it's a good base to start with. And there is about 10 hp to 12 hp to be gained with going bigger. That's 10% gain in hp and torque....per Dave dodge racing. The port and polish with cams and pipe should yield about 110 hp at the rear wheel. With the suspension mods it should really modernize it, for a fraction of the cost of a new bike. Have you seen the cost of new bikes lately....depressing. Link to comment Share on other sites More sharing options...
FTM Posted November 11, 2012 Share Posted November 11, 2012 Where did you get the Kerker? and can we have a photo of the bike please. Link to comment Share on other sites More sharing options...
Member Contributer ron_al Posted November 11, 2012 Member Contributer Share Posted November 11, 2012 In response to the OP: So...rear shock upgrade, about $400 Are cartridge emulators available for the front? Looks like a set of CBR wheels (or others that can fit) would run upwards of $300 and likely need new rubber. And new bearings. My swingarm pivot is sloppy, that needs to be replaced too. I don't know anything about the radial brake master cylinders, or how much they run. I think my rotors are warped too. They drag for half of the wheel's revolution when I'm pushing the bike. What else goes on the wish list? Regarding the front end & wheels, you may want to determine if the goal is to stay "stock-ish", or to upgrade the hardware (a la Frankenviffer). If you stay with the stock front forks, then yes, it appears Race Tech does offer their gold-valve cartidge emulators for the 1986-1987 VFR700 front forks: part # FEGV S3501 from their website here http://racetech.com/ProductSearch/2/Honda/VFR700/1986-87 For front brakes, it would appear that you can replace rotors with aftermarket rotors: Galfer lists a part number for a replacement front rotor at http://www.galferusa.com/catalog/ and EBC list the VFR700 as well http://www.ebcbrakes.com/ I read in the Nov-2012 issue of Motorcycle Consumer News about the benefits of upgrading to a radial pump front brake master cylinder, even if keeping otherwise low-tech brakes. (They upgraded to a Brembo radial front master cylinder on a Suzuki DR650 dual-purpose bike, with a single 2-piston front caliper.) I already know that some people would advocate getting a full replacement front end off of a later-model bike (probably gaining USD forks and/or cartridge suspension and/or better brakes and/or wider wheels). This would also mean that you are also exchanging the tradeoffs from your VFR700 forks for the tradeoffs in whatever fork you swap in. Good luck with whatever you work out! Ron Link to comment Share on other sites More sharing options...
Guest Posted November 13, 2012 Share Posted November 13, 2012 Great info, thanks! Does anyone have suggestions on a front end swap? How do I go about finding out what would work without major machining? Link to comment Share on other sites More sharing options...
Guest Posted November 13, 2012 Share Posted November 13, 2012 well from what i have read in my research on the subject...the 91-94 cbr 6000 f2, as well as the F3 is the easiest to swap. also the yzf600 i think, not sure of what year. plus an abundance of info on the swap. but i used 91-94 cbr600 forks, installed racetech gold valve emulators and sonic spring(1kg if i remember right) which upgrade them to modern fork technology. used a jaime d upgraded rear shock and f2 rear wheel. the brakes from what i have read are great on the F2, but you can use various bikes brakes, you might have to machine a mounting bracket though...but i know there is a already manufactured bracket for the F2 that give you 320mm rotors. since yours is bad anyway. i heard the sinister brake pads is a great upgrade as well. i considered a 700--> 750 engine upgrade as well. but only gaining 6hp wasnt that serious to me, since im only going to go so fast. but with the reduction in weight from the F2 conversion(F2 wheels versus vfr wheels are a HUGE weight lose), as well as the updated suspension in the rear and front...i personally think that would be what you are looking for. just my 2 cents. also EBAY will be your best bet to cut COST on the swap...i might have another CBR600F2 triple tree or a lot of parts i got "to many of" if you want them. also for the rear....chuck crites does a modded vfr rear break caliper stay(basically cuts so much metal out and rewelds) or you can just use the CBR rear break caliper stay with very little modifying Link to comment Share on other sites More sharing options...
Member Contributer crepitus Posted November 14, 2012 Member Contributer Share Posted November 14, 2012 What I've done so far: Race Tech Fork emulators New 95kg springs. Fox Twin Clicker & spring (Jamie Daugherty) Suspension setup by Willis Cycle Works and it rides like a new bike :) Next is mounting a CBRF (hurricane) wheel up front since it's a bolt-on. I'm going to mount an old Pilot Race to it and compare it side-by-side with my buddy's CBR600RR front to see just how much the narrower rim affects the profile of the tire. If it in fact bends the sidewall too much, I have two options: 1.) A local company, framestraight.com, can widen a rim. The way the owner described it was not too bad to do. 2.) Get a CBR600F2 front wheel and machine spacers and the rotor posts. I'll check with him on which option is the most feasible and cost effective. Next would be the F2 rear wheel. I'm hoping I can get these done by spring so I can mount some superduperfly sticky rubber and test it out at the track. Link to comment Share on other sites More sharing options...
577nitroexpress Posted November 17, 2012 Share Posted November 17, 2012 Where did you get the Kerker? and can we have a photo of the bike please. Where did you get the Kerker? and can we have a photo of the bike please. I just got the engine, wheels, and bits. I actually have two shocks now to choose from. Olhins and the fox twin clicker. I might put the fox on my built 85 rz350, as it would not need modifying. Found the parts on eBay, guy in cal has a ton of 86 parts great guy to deal with, has three more 4 into 1 exhaust and some more 750 engines. Link to comment Share on other sites More sharing options...
Guest Posted November 20, 2012 Share Posted November 20, 2012 So much info, I don't even know where to start! It's extremely helpful that folks are doing the same thing I have in mind. I just never get tired of this bike, I'm more and more sure it will be worth the cost to bring it up to date. Link to comment Share on other sites More sharing options...
Member Contributer dadofseven Posted November 20, 2012 Member Contributer Share Posted November 20, 2012 Not a lot of difference in the 2 motors. Only a couple cc's and a couple HP. Spend your money on a newer VFR. 93-97 is a good step up for that type of change. still 750's and more modern. Good luck! Link to comment Share on other sites More sharing options...
Member Contributer crepitus Posted November 20, 2012 Member Contributer Share Posted November 20, 2012 So much info, I don't even know where to start! It's extremely helpful that folks are doing the same thing I have in mind. I just never get tired of this bike, I'm more and more sure it will be worth the cost to bring it up to date. I probably have more in the suspension upgrades than the bike is worth in its present condition, but that's not what it's really about. Link to comment Share on other sites More sharing options...
Member Contributer wagzhp Posted November 20, 2012 Member Contributer Share Posted November 20, 2012 I don't have any details, but the 87 vfr700 we picked up has gsxr USD forks, tripple trees, brakes, wheels, and what looks like a Fox shock on the rear. Apparently the gsxr swap is semi-common. The bike rides pretty nice, but I haven't pushed it hard at all, so I'm not sure how well the package was tuned. I do know that it stops very well wtih the gsxr brakes and modern rubber. Link to comment Share on other sites More sharing options...
Guest Posted November 22, 2012 Share Posted November 22, 2012 I probably have more in the suspension upgrades than the bike is worth in its present condition, but that's not what it's really about. Yeah, that. I certainly didn't pay much for the bike in its wrecked and neglected condition. Link to comment Share on other sites More sharing options...
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