The cooling system components on Project 41, an '87 VFR700 F2, were completely removed and disassembled for the bike's resurrection. The individual pieces were cleaned, "de-corroded," and polished or repainted as necessary. Fresh seals, a new OEM thermostat and silicone hoses with new clamps from AS3 were sourced and even a new GPI aftermarket radiator. Time to put it all back together. These steps will generally apply to all the V4s.
(click on an image to enlarge)

(Below) I begin in the cylinder valley by assembling the two fittings and their chrome connecting tube. These components were in tough shape and separating the chrome tube was an effort. After a lot of prep, the parts were ready for assembly with their new, lubricated seals. 

(Below) Next I move to the lower chrome pipe and short water pump hose. The pipe looked terrible upon removal but proved to be mostly surface corrosion which cleaned up with 0000 steel wool and chrome polish. After sliding the lower hose and upper o-ring seal onto the pipe, I insert the upper portion and slide the lower hose onto the water pump housing, lining up the support bolt hole. Then I install the support bolt so everything is correctly positioned before tightening the two lower hose clamps. 

(Below) The water pump cover is next. The new o-ring seal won't want to stay in place during installation, so I coat it with a film of grease to hold it. I'll refer to my cheat sheet to match the bolt lengths to their positions — note how to measure bolt thread length. Tighten the bolts in an alternating pattern, and it's good practice to renew the drain bolt's crush washer.

(Below) Turning my attention to the right side of the engine, I'll first bolt the small coolant nipple onto the engine block with its fresh o-ring. Next I assemble the new thermostat and housing, and screw in the temperature sensor with a few turns of pipe tape (I don't think the sealing tape is necessary, but it makes me feel better). Plug in the sensor's wire connector before installing onto the engine — if you forget this connector, just use a long needle nose pliers to reach it once the housing is installed. Next I install the coolant hoses with their clamps loosely in place and this assembly is ready to go onto the engine.

(Below) The rear hose is slipped onto its nipple, but not tightened, and the thermostat housing is then bolted into place — don't forget the o-ring between the housing and the engine block. Note that there's a long and a short bolt; here the longer is being installed. Lastly, the rear hose clamps are tightened.

The next step is to install the radiator, and I'll enjoy easy access with the forks temporarily off the bike. For this project we've chosen a GPI aftermarket radiator (see Shop Blog post from Aug. '24), but the installation is the same for an OEM radiator.

(Below) Before beginning, I'll polish the chrome oil cooler lines while the radiator is out of the way. Some of the Gen-2 bikes are supplied with black lines, but these chrome lines were covered in dirt and surface rust. About ten minutes with chrome polish and crumpled aluminum foil has them looking new. A soft brass brush helps to clean the difficult-to-reach areas. In the final photo, note the pre-installed Hindle exhaust pipe adapters and springs.

(Below) The radiator is first slipped onto a stud located on the upper right side of the frame (note the fan wires exiting outboard of the rubber grommet), then the special left-side bracket is slipped into place in the rubber radiator grommet and bolted loosely into the frame. Then work the oil cooler hose into the wire bracket.

(Below) The two lower mounts are next. Often, the grommets won't line up with the frame brackets, as is the case here. I simply loosen the brackets' mounting bolts which allows me to align the radiator bolts and brackets. Tighten the three radiator bolts and, lastly, the lower bracket bolts to the frame. 

I've recently been working to clear my backlog of carburetors in need of rebuilding, consisting of five sets of Gen-3 carbs. It's always a bit like unwrapping a gift when I begin disassembly of a dirty set, never knowing what I might find lying in wait. Clogged jets and petrified gaskets are expected, but there's also broken bits, incorrect parts and creative assembly from past attempts by well-meaning DIYers. Here's a sampling of typical chores.

(Below) These carbs' vacuum diaphragms are afflicted with some sort of white and green stuff, possibly mold or mildew? These slide assemblies are NLA so I treat them with a delicate touch. Here I'm using Zep degreaser, a mild cleaner, massaging the rubber diaphragm with finger pressure and a soft toothbrush around the edges. In extreme cases the round rubber edge can be coated with stubborn crusty corrosion from a rusted diaphragm cap — a challenge to remove without damaging the diaphragm. I use a warm soapy bath and a fingernail to gently scrape the crust off as best I can. If the rubber seems particularly dry I will rub on a thin application of red rubber grease to rejuvenate and preserve the rubber.​ I also clean the plastic slide by scrubbing with a non-scuff kitchen pad followed by a hot water rinse and air dry.

(Below) The main jet needles are often stained with sticky brown varnished gasoline. This I remove with a scrub pad and degreaser or solvent. Two of these four float hinge pins were very difficult to remove due to varnished gas. Here, I'm using 1200-grit paper wetted with Ballistol to cut the varnish, allowing the floats to pivot freely. I like to roll these items (and the pilot adjustment screws) on a flat surface to check for straightness.

(Below) I'm no longer able to source individual float valves for the Gen-3 carburetors, so I rely on Keyster rebuild kits, which are quality Japanese-made parts. Next, this particular carb set had a broken enriching (choke) valve — these are soft brass and don't like to be forced. I learned this long ago when trying to remove a stuck valve by pulling with pliers. It didn't take much force to pop that little head right off, like the one shown here. This one had a bent tip which expectedly broke when straightened. Note that there's two distinct parts here…one has a wider gap to allow room for two pieces of linkage on carbs number 2 & 3 (red arrows). I clean these shafts with 1200-grit sandpaper wetted with cleaner/lube, like WD40 or similar. Shown next is an air cut valve assembly. These are often reusable, like this one, if treated gently. I carefully clean the rubber diaphragm and apply a light film of red rubber grease to preserve it. These assemblies should be removed when performing a thorough carb cleaning.

(Below) Here's two shots of the various parts cleaned and ready for assembly. The pink arrow shows how I mark each carbs' float with permanent marker dots. This way they maintain what float level adjustment they had previously, saving time setting the float heights after installing. I also keep the slide assemblies with their original carbs — not necessary, but my thinking is that each is well mated to their carb, so may as well keep them paired. 

The good news; my winter off-season is half over! The bad news; my winter off-season is only half over. In any event, I'm making the best of it — Project 41 is in the assembly stage and coming together nicely. I've finally found time to get several sets of Gen-3 carburetors rebuilt, just waiting for the opportunity to get them tuned. For that I'll utilize my '93 VFR, but the lift is occupied with #41 for the time being. Parts orders and inquires are increasing as the season turns the corner, a sure sign that warmer days are coming.

As a mid-winter pick-me-up I'll share a 5-minute video from YouTube's V4 Rider, this time on a tuned Gen-8 VFR800 riding the Pampilhosa da Serra mountains in central Portugal. I like his riding style…note his cornering lines, he's a fan of the late apex, as am I. Also note his throttle/clutch/shift technique; he's very precise and barely fans the clutch lever — sometimes ignoring the clutch. He's good. Enjoy.

What: 1997 RVF400 (NC35)
Why: Beautiful, desirable, rare
Where: Orlando, Florida
Price: Auction; BIN $11,500

Often referred to as a smaller sibling to the RC45 (previous post), this little screamer was only available in the Japanese market. This final iteration of the 400cc V4 was a comprehensive upgrade over the earlier VFR400. Production actually ended in 1996 but left-overs were available for a few more years, explaining this 1997 example.

And this one enjoys a sampling of modifications, including Tyga bodywork, Ducati rear wheel, several carbon fiber bits and more. Whether these changes make the bike more or less desirable is up to the buyer to decide, but the buy-it-now price of $11,500 is in line with more original examples. Note that there's no mention of the missing turn signals and mirrors.

If you're the appropriate size and have the required flexibility, then the RVF400 is reportedly among the finest handling and fastest in this class. According to MCN, "Honda at their very best."

What: 1994 RVF750R (RC45)
Why: Rare, low miles, original owner
Where: Torrence, California (LA)
Price: $69,000

If you're still reading beyond the $69K price, you must know what's on offer here. Produced by Honda's HRC division for World Superbike competition, 200 road-going homologation RC45 examples were built, with only 50 going to the U.S. This model was an upgrade replacement for the iconic RC30, notable changes including fuel injection and shortened stroke. The U.S. model was rated at only 101 HP, the Euro model at 118, but the full-on race bikes could go to 190 HP. The bike distinguished itself with many important titles, including:
1995 AMA Superbike Championship
1996 Daytona 200
1997 WSB Championship
1998 AMA Superbike Championship
FIM Endurance World Championship SIX times!

This particular example, #43, is offered as an original-owner with only 3050 miles showing, and "total stock, untouched." Arguably the worst ad I've ever come across for such an exclusive and expensive motorcycle, it includes six bad photos and only 18 words in the description. I guess our seller assumes the bike will sell itself, and that's probably true. The most recent comparable I found is a 903-mile example sold on BaT 15 months ago for $66,500 (+buyer fee), so the asking price is in the ballpark. These bikes are few and far between, so here's your chance to own a piece of superbike history.

I'm always on the lookout for parts bargains. They're not as common as they once were, but a sharp eye can still spot one now and then.

Here's a great example. This is a New Old Stock Gen-2 rear Disc Pad Pin Kit from EBC. I've never seen one of these but what a bargain! This kit contains a collection of hardware you may want or need for your caliper rebuild, not commonly found in a caliper seal kit, for example.

From left to right in the photo, we have the no-longer-available "hanger" and its attaching bolt which secures the pad pins, followed by the two pad pins, and finally the pad spring. The pins and spring are still available from Honda, but if you were able to purchase all of this separately it would total about $70.

Our seller has this kit listed for only $10 including shipping! And, within one hour of my adding the listing to my eBay Watchlist, I was sent an offer for $9.50 — that's a little discount trick I've often used over the years to save a little on the hoards of parts I've had to buy.

I don't have a need for these parts, but if you're doing a complete caliper rebuild, maybe you do. The remaining parts required would typically be piston seals (K&S 19-1005) and the lower slider "sleeve," Honda part # 45111-MA3-006.

In the latest issue of Rider magazine, I came upon this on-road review of the Bridgestone Battlax BT46. These tires would be spec'd for the Gen-1 and Gen-2 VF/VFR models, as they're bias-ply construction — later models wore radial tires. There's very few tire choices out there for the 16" fronts/18" rears in the correct OEM sizes. I've sampled them on the Gen-2 but have always returned to Bridgestones, first the BT45, then superseded by the current BT46. There's more selection if you want to stray from original sizes but I've always found that the engineers got it right to begin with.

Our reviewer tested these on a newer Royal Enfield 650 and came away very impressed, with comments like, "reassuring grip," "predictable behavior, "clear feedback," and "precise handling and confidence in every corner." I agree; these tires are grippy, versatile and priced right. They even sport current tread design, giving a touch of modernity to our old bikes.

Also shown below are current prices from Rocky Mt. ATV/MC (Gen-2 VFR).

As a handy new year's bonus, posted below is a PDF file of an index to the major technical posts on this web page since the inception of V4 Dreams nearly ten years ago (!). It's provided by reader Michael S. through his thoughtful and generous effort. My web hosting platform doesn't provide for a search feature for the the "Archives," so I'm very grateful to Michael for indexing some 115 months of posts.
Scroll through the index on this page or download by moving your cursor near the bottom and clicking the download button.