1995 VFR750F refurbish

Hi all, some of you saw my wanted thread. I am starting a thread here as I successful found an original survivor RC36-2 that has been motionless for what seems like well over a decade. Overall in great stock shape, a few minor issues and marks externally (30 year old bike) but a great project and starting platform for me. Bike is a 95, build date 11/94, with 2 owners and 12k miles.

I have already started stripping her down and plan to do a good replacement of all fluids, clean carbs, replace all the necessary rubber parts and O-rings and get her running again.

I'm going to be reading through Captains two threads for lots of details on the rebuild:
https://vfrworld.com/threads/95-vfr750f-refresh.59390/
https://vfrworld.com/threads/1992-vfr750f-rescue-refresh.60160/

And when she's all finished I'm going to show it to Captain in person, as he is a work neighbor!

 

After picking up the bike from CA, I trailered it back to Seattle area.

So far I have pulled all plastics off, removed fuel tank and pulled the carbs off.

Notes so far, and I welcome suggestions for how best to deal with some of these things, or just general advice:

1. Drained fuel tank. Gas was nasty and very old and dark in color. I don't see rust in there but I will need to clean out the tank with something. What do people flush tanks with? Is the access OK through the fuel sender opening to clean?
2. Fuel strainer hose 16956-MZ7-000 was cracked and fell apart on me. Will source an alternative pre-formed fuel line as OEM Honda not available.
3. Clutch slave cylinder missing an M6x20 flange fastener. Thankfully I've had a few dirt bikes that take metric fasteners so I had a Yamaha fastener that is an exact match.
4. Pulled carbs off, was as tough as I remember the 1989 RC24 that my dad had when I was younger. But gentle prying and patience got them off. Float bowl fasteners are pretty marred up, will need to get new fasteners to replace those. Someone rounded out the Phillipsheads when working on it in the past.
5. Cleaned up fork stanchions, was some grime on them, thankfully not corrosion!
6. "H" button on clock adjustment was stuck inwards. Carefully opened the front of the gauges and poked it back through.

Next steps:

1. Open up the carbs and see how dirty/varnished they are. Figure out how to remove and clean all jets.
2. Drain coolant and get the center pipe above motor off so i can replace the recommended O-rings there.
3. Do a little repair work to the two little plastic tangs that mate the upper cowl to the mid fairings, these got broken at some point in the last 30 years.
4. Need to start pulling all the PAIR and EVAP system off as that was a CA thing. Will need to pick some brains on what ports need blocking off or which hoses need rerouting.
   
5. Bleed clutch - fluid is low and seems like it's not doing anything. The missing fastener has me thinking about something weird going on here
6. Bleed brakes with fresh fluid
7. Once everything is all cleaned up and reinstalled I'll see if she fires up, then I'll see about balancing the carbs and then oil/filter change

This list is going to keep growing for sure. Thanks in advance for all your collective knowledge and help getting me through this project. I'm very excited and hope to have her road worthy later this summer!

I've attached some pictures to make the thread more interesting!

 

You made your first mistake. Always keep the aluminum plenum in place when removing and installing the carbs. It puts too much stress on the fuel tubes and linkages.

 

Whoops! Good info, thanks Captain. I'll be sure to install the plenum when installing the carbs again.

 

Read, read, read. Then read some more.

Ask questions. Then ask some more.

I know you want to dive in, but a Genuine Honda Service Manual would have shown to keep it in place. Often it's just a "Whoops!". But sometimes it's a "FUCK".

"Hey everybody, I've never pulled and rebuilt V4 carbs before. Anything I should look out for before diving in?"

Thats a big part of starting a thread.

 

Understood! Thanks for helping me succeed here.
I just borrowed the factory service manual today from my work colleague.
I watched a couple videos before pulling the carbs, but those were from an older RC36 and the plenum wasn't attached. Also the last time I pulled the carbs from the RC24 it was 20 years ago and my memory isn't good enough to remember the details, other than I had to carefully pry them out also.
You are right, I need to slow down. I'm too excited.

 

Awesome. FSM is a big part of the equation.

Then they were also doing it wrong. And took video of themselves failing.

Pry... Usually. But as a unit.

Also, heat gun is your friend on removal. Which you would/should have known.

I'm sorry. Long afternoon. I'm tired and (more) surly.

Cheers.

 

Grab some coffee some morning or some whiskey some evening and read my two RC36 threads all the way thru.

There's some fluff and banter in there, but there is also specific instructions about doing everything you want to do and a shitte tonne of clues in the pictures.

I love being where you are. The start of an awesome project. When I started I wish I had the resources and documentation available now.

 

Kenny.....I don't visit the Gen-3-4 forum much because I only have 1 Gen-3, but wanted to stop in and say congrats again on your new bike and what you have ahead of you in restoration and maintenance.

My only comment is - like the Capt has already stated - spend some time reading his threads along with whatever else you can find on any particular topic you are researching BEFORE you dive in on the actual work. As far a reading material....I have the FSM, Clymer, Hanyes, and owner's manuals for every model I own. Not a single one has everything you need, so a good investment to buy them all if you truly want to maximize your educational potential.

The fact that you are on this forum though and having Captain 80's here to assist you with topics is probably the best thing one could ever want in your position. I cannot tell you how much I have learned from his replies to my questions, other member's questions, and his general commentary on many different topics.

Have fun and just take your time on stuff. You'll get there......

 

Thanks for the advice Bazza and Captain, I did dive in pretty fast in to the bike. My plan was to start getting acquainted with the new family member/new project and not jump into anything I was unsure of. I have worked on many cars and bikes in my time but there are certainly some special tricks to learn and some deep knowledge and experience here in the forums - I am super excited to learn about this bike.

Weekend was mostly spent ogling the bike and reading the FSH, in addition to reading Captains two threads (I have read them twice now and I think I will need to read them a few more times to fully digest everything in there - wow, impressive work Captain!). I also might have changed my initial plan on the PAIR EVAP system. I didn't realize there was a CA version with different cams, cam timing and jetting. I guess coming from the UK I was not aware of this. I feel a little bummed about this as it seems the CA cams are mellower and even removing the emissions equipment and changing the jetting will not get me to the 49 state motor. Saying all that, maybe the difference isn't super big. Suffice to say my plan will be to leave all the emissions BS in place and get the bike running for the summer. Maybe over the winter after I'm fully acquainted with her I'll jump back in and remove those systems, block them off etc.

OK, so the things I did get started on this weekend were:

1. Flushing and bleeding the clutch, unsuccessful - pulled the slave cylinder off to clean out the gooey old dot 4 muck.
2. Pulled the thermostat and water pipe and connections to the heads. The o-rings to the fittings that mount to the heads were pretty much gone. Coolant was a nice clean green though. I have only got one end of the connection pipe out though, the other is stuck pretty good. Any ideas on getting this free'd up? I've only been using my hands so far, don't want to go crazy on it yet.
3. Started cleaning out the fuel tank. No rust in there but some decent varnish. Also the screen part of the petcock inside the tank went so brittle it broke at some point and pieces of orange plastic are all in the tank (have removed them now). I also found there are no new petcock assemblies out there, maybe I'll get lucky on eBay. I actually only need the screen part, but that's not for sale separately from what I can tell. Question on removing varnish from the tank. What is everyone's special trick/chemical? Currently I've just removed the sender, plugged the hole, thrown a bunch of ferrous nuts/washers in there with about 0.5gallon of clean gas and been shaking it around. I have got a decent amount out but I probably need to go with harsher chemicals - I just really don't want to damage the paint.
4. Started cleaning the carb jets, just soaking in some chemtool B12 to start. A few are blocked. I am toying with the idea of getting a small ultrasonic cleaner, is that what people here generally do? Or just carb cleaner with air compressor to blow them out?
5. Noticed two of the choke valves are stuck, started cleaning these too, free'd one so far.
6. Started populating the O-Ring data from Captains threads so I can order all up in one order, super helpful resource - thanks again Captain!

Generally just chipping away at it and really enjoying working on the bike. It's rare for me to be the first person to wrench on a bike/car. This bike has been untouched and there is really hardly any corrosion anywhere, everything comes apart perfectly. It's a joy to work on! I'm so excited for the moment when I can fire it up, even though I know I've got a lot to do before that moment.

 

Couple things regarding CA and PAIR.

Don't fret about the cams, its not a very big difference. My 1992 is(was) a CA model. I do have 49 state cams to put in it when I go thru the valves soon, but it is no slouch. Faster than my buddy's 49 stater, but I put 94 headers on it too.

Now is ABSOLUTELY the time to ditch all of the other bullshit. Its not more work. Remove everything. It's a matter if plugging a few holes and spigots. You can even just loop some vent ports over to another one with the 3 miles of vacuum tubing you'll be removing. You can wait on the hard lines if you want, the rears are kinda a bitch. But get the fuck rid of the PAIR valves and just loop the hard lines back on themselves.

I just use carb cleaner and compressed air. Ultrasonic is nice for the misc hardware, but I am hesitant about putting the whole bodies in one and introducing moisture into the throttle shafts. I know in reality it's not the end of the world and can be done, but I'm old school in this area.

Go up one size on your pilot jet. Maybe two since yours is a CA and it's perhaps already smaller than a 49 stater.

 

Go on then Captain, you've twisted my arm, PAIR and EVAP will be removed! I'm wondering if some simple sheet metal blanks might work for the hard-line cylinder head attachment points, to plug it. I know you cut and plugged the hard-lines with a fastener close to the heads.

As for jets, mine has the same 40 slow jets all around, same as 49 staters. It's the main jets that are 128 in the front, (125 rear) vs the 49 stater that is 125 all around.

Should I (a) go 125 all around for main jets and (b) go larger on slow jets? Or (c) something you recommend from experience. I'm going to be running the stock exhaust and muffler to start as I'm a sucker for the "original" styling of the bike.

I haven't checked the pilot screw position yet as I need to purchase a tool.

 

Don't know why Honda staggers the mains on this bike just for CA. When they normally do that it's on all versions. You could stick to those, doubt you would ever feel or tell the difference if you dropped to 125 up front. If I was buying jets tho I would buy 125s.

I go up to #42 on these bikes, but you'll probably be just fine as is. I just prefer coming off of "choke" earlier and like how it runs pulling away from stops. You can meter that circuit down with the pilot screw no problem. I would rather meter down to under 2 turns out than trying to clean something up towards 3 turns out.

I'll be happy to stop by sometime and point at exactly what you need to do to eliminate the CA and PAIR bullshit. You can take notes and pictures.

Cheers!

 

More progress this week, ordered first batch of o-rings and gaskets, jets, pilot screw tool etc. Also removed all the PAIR and CA emissions stuff. The rear hardlines were indeed a pain to remove. I pulled the rear shock to get better access. I have blanking plates ready to go.



I spent some time getting the vast majority of the varnish out of the fuel tank, thankfully no rust but it was still a mission of cleaning. I'm pretty happy with it and will just keep an eye on the fuel filter and replace regularly - especially as I have no screen in the petcock now. I tired looking online for a 24mm diameter screen to no avail. I did find mention of the Superhawk and Blackbird petcock filter screens that may fit, but nothing confirmed.

I found that the petcock is leaking internally (not surprised), so my next task is to drill the rivets out and tap for M4 screws, and replace all the orings in there, maybe even a stronger spring while I'm at it. I will order up the o-rings for those in the next batch.

Questions for the hive mind:

1. What are the dimensions for the pilot screw o-rings? I assume those are typical ones that need replacement. I have found mention of the size online (2.7mm x 1.15mm). Does that sound correct? (Without my pilot screw D tool I haven't yet taken them out).
2. Has anyone replaced a Showa rear shock bump stop? Mine is cracked and rock solid. I measure the size ~ 45mm OD, 14mm ID and 24mm long. I have had to replace bump stops before, last time was on a Olle trials shock and I had to thread off the eyelet. The Showa looks like there is an internal nut on the shaft that might be the key to getting a new bump stop on. First I have to remove the spring, which isn't in the service manual, any tips on that?
3. The fuel lines between the carbs are rock hard, I have new o-rings for the plastic tubes but am thinking of replacing the flexible lines also. Is that typically what people do? 10mm (~3/8") ID lines? Or re-use as they are perfectly hardened into the correct shape!
4. After PAIR and EVAP removal I know I have a lot of ports to block but some to leave open, is my below list correct:

• Cap two large (~13mm) elbows at the front of the airbox
• Cap front two cylinder head ports (the ones used for carb sync), so they match the same as the rear cylinder heads
• Remove the excess small vent lines from between the carbs/side of the carbs, and cap brass spigots on carbs
• Leave no. 6 hose vent open to atmosphere (used to go to EVAP control valve)
• Connect main large hose to rear cylinder head as before

Picture questions might be easier:


Final thought/question. I am not sure when the motor was last turned over. Should I pour a little oil (I have some Motul 710 2-stroke oil in mind as it's what my offroad bikes take) down the spark plug holes?

Any other thoughts on a methodical and safe way to fire the bike up first time? I'm still a couple weeks away from this momentous event, but I'm thinking about it already!

 

Good man!!! Doesn't it feel good to have all that shit off now?

1. I haven't had to research those yet. Unlike the rest of the orings, those seem to last a lot longer and I have a pretty good selection of spares from parts bikes. But that dimension does sound right for the small one.

2. You will need a real shock holder and hydraulic press for that spring. The little aftermarket compressors are usually not up to the task. Be careful!!!

3. If they are as hard as you say, you should replace them. For the weird, hard bends you can get pre-formed fuel line lengths that have multiple angles and curves on Amazon. They are high quality, dual layer reinforced. (Just a quick example, research what size you need)




4.
- Yes. I have some caplugs for you if you want.

- Yes

- Yes. I use the some of the 3 miles of vacuum line that was removed and connect the front two carb bowl vents with each other and the rear together. Unless you have very high quality caps you won't worry about being exposed to many heat cycles.

- Yes

- No. The large one also vents to atmosphere. On a 49 state bike there is a little filter box that bolts to the air box base that it runs to. It is not necessary, just make sure it points down. Here is my 92 with the little filter box. A tube goes from the air box base to the cylinder head.




Final question... Can't hurt. When ready to fire, I would crank in spurts until the oil light wants to go out and then put the kill switch to run.

Also, if you got new plugs, I like to wait until after the first run and let the old plugs burn off all the shit.

Good job!!!

Also I think the Blackbird screen is correct, but can't absolutely confirm it.

 

OK folks, making more good progress here. I even fired the bike up yesterday evening - what a great feeling it was to hear her come to life!

I'm still tidying up parts all over the place and want to make sure I'm doing the right thing on the carb venting before moving on to other tasks. Question:

1. Should I cap the yellow #11 hose that used to go to the EVAP purge control valve? It's on carb #1 by the pilot screw. Is this a vacuum signal to the purge valve? If it is, I should probably cap it and not tie into the float bowl vent lines (blue lines below). Although tying into blue vent lines would be tidy (no caps to worry about deteriorating as I'd be using the nice OEM vacuum hoses). I'm concerned pulling a vacuum on the float bowls would be a bad idea, hence the question.
2. Looking at hose group #5 that joins all the float bowl vents, I assume I can't cap these all individually as they need to vent to let the fuel in the bowls. So, does it matter which float bowl vents I tie together? I found it easier to join #1 and #2 together, and #3 and #4 together, the plenum plate made routing difficult between it and the central carb spine. (I suppose I could have gone around the outside perimeter easily with longer hoses...).
3. Green hose #6 now just vents to atmosphere, I will make sure it gets a new bit of hose and points down and out of the way somewhere.

Old picture before i removed EVAP and CA stuff:




When I have some more time I'll put up an update on everything I've done so far, including the petcock rework incl o-ring sizes, PAIR blanking plates, pilot screw o-ring sizes and more.

 

Yellow is vacuum. Either cap it with a high quality piece or connect it with some vacuum line you now have to a vacuum port under the one of the insulators (the ports used to synch). You can't tie into venting, it will F with things.

Tie the blues together however is most convenient. The way you described is how I prefer. Front two and rear two.

Yes, green to atmosphere ending at a downward angle.

Large diaphragm vent tube goes to atmosphere. Either to the little "pre-filter" box. (don't worry about the missing foam), just pointing down or run it to a little breather filter. I like the UNI version (no chrome cap to bang on things) with the zip tie tab, but they are kinda expensive for what they are.

 

I am now hooked. I should have read this earlier, but I will use your thread to learn from. My 94 is waiting, but I will be performing the same work. Thanks for finding all of the trouble spots.

 

@RogueRC24 - you are going to have a great time. It's so enjoyable to work on these bikes. They are so well designed and engineered!

I have been busy chipping away at a lot of tasks and with the bike ~95% complete I felt it was time to take it for a trip to work and show it to @Captain 80s ! The RC36/2 has such a fantastic meaty midrange (where you spend the majority of your time). It is overall an extremely refined machine, I'm so happy with her!

I will find some time to list up all the work I completed below, but for now let's admire her beauty!

 

I walked down and checked it out a little bit ago.

Real nice bike. Sounds GREAT with a good idle and crisp response. Kenny's carb work was on-point apparently.

Tidy little block off plates for the PAIR hard lines. Bodywork largely unscathed which is rare for these bikes. Very original, complete example.

Good job!!!