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Trying To Revive A 1993 Vfr 750, Incomplete... And Flooded!


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Thanks for your inputs @Dutchy & @JZH. Will wait to cure the pump for now. 

I removed the exhaust pipe in order to get it sandblasted then will spray it with high temp paint.

Will also remove the front fork for inspection, change of oil/bushing/seals and review of the compression/rebound stack.

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  • 2 weeks later...
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Wow nice thread! Im glad I found it. Question with the carbs. I just did the same with mine rebuilding with the Lite Tek kit. Now putting them back togeher Im having a tough time getting the choke slides to function properly. I imagine the carbs are ever so lightly twisted or out of line (even with both plates on). If I losen them, I can get them to function properly but once tightened they seem to adjust and lock up.

 

 

any pointers on putting these back together?

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@NISxMO I know what you mean. All I can suggest is that you start with disconnecting the choke mechanism for carbs #2 and #3. This is done by unscrewing the 2 bolts noted #34 on this diagram:

http://www.cmsnl.com/honda-vfr750f-1993-p-france_model5630/partslist/E__1600.html#results

Then choke lever should at least open correctly carbs #1 and #4 with the 2 long arms noted #22. If that works ok, then you have to adjust the position of smaller arms #20 one remaining carb at a time. You should then be able to open all 4 carb lever with the left hand side bar lever.

I hope it helps.

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Just removed the 2 fork legs. Only open one that had the fork seal leaking. 

 

This is how oil of a never serviced fork looks like: like engine oil way over the service due milage... I would guess service was needed somewhere at the end of the 90's (remember we are in 2017?) 

 

large.20170325_145314_1024.jpg.521a660dce6a16857aa927e3c76aecc9.jpg

 

Fork seal is... I have no words to describe it:

 

large.20170325_160203_1024.jpg.90a6a9f34cb26a53b75c04d252da9226.jpg

 

Bushings look normally worn to me, will change them anyway.

 

large.20170325_160317_1024.jpg.9ff4ff6fb190b2ed0b3df68ee50fd9b1.jpg

 

This is how far I was able to go:

 

large.20170325_160103_1024.jpg.74c787d5d8f980976ea9efed17b7efb0.jpg

 

I understand the right part is where the magic happens (as Dutchy would say). I did not understand how to dismantle this assembly (noted fork cylinder assembly in the manual).

Does anyone has an idea on how to proceed? 

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Google gave me the answer:

http://www.vsource.org/VFR-RVF_files/BVFRforkservice.htm

 

Here it the bottom of the cartridge:

 

large.20170326_122843_1024.jpg.d9d3443f3b7a8b74f2a7df9fff35a5d5.jpg

 

You can just push the bottom part - which is in fact the compression rod - with your finger. It is retained with a C clip:

 

large.20170326_122928_1024.jpg.0a56c5a3254090206bae9437759d442c.jpg

 

Remove it and you can separate the whole assembly 😉

 

large.20170326_123924.jpg.9a77b4ccf086f0dcbb23db254b63892f.jpg

 

Have to order the Honda parts: fork seals and bushings, dust seals. And extra shims to upgrade the compression and rebound stacks. Will also order a fork seal driver 🙂

To be continued... 

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I found some water inside the 2nd fork leg... I cannot figure out how, the fork seal was not even leaking...

Envoyé de mon SM-A510F en utilisant Tapatalk

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Blimey, that fork seal is...beyond words!  I think everything on this bike should be inspected--I wouldn't take anything for granted.  (Check inside the tyres!)

 

Ciao,

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On 25/03/2017 at 4:32 PM, bdouvill said:

Fork seal is... I have no words to describe it:

 

20170325_160203_1024.jpg?raw=1

 

 

Are you sure that needs replacing ? :goofy:

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On 3/25/2017 at 11:23 AM, bdouvill said:

@NISxMO I know what you mean. All I can suggest is that you start with disconnecting the choke mechanism for carbs #2 and #3. This is done by unscrewing the 2 bolts noted #34 on this diagram:

http://www.cmsnl.com/honda-vfr750f-1993-p-france_model5630/partslist/E__1600.html#results

Then choke lever should at least open correctly carbs #1 and #4 with the 2 long arms noted #22. If that works ok, then you have to adjust the position of smaller arms #20 one remaining carb at a time. You should then be able to open all 4 carb lever with the left hand side bar lever.

I hope it helps.

 

 

Thanks Bdouvill! I took them apart multiple times and could not for the life of me figure out what was wrong, especially when the plates were all lining everything up..... in the end I realized the center plate may have lined up but it was actually flipped 180 degrees from the correct position. 

 

Keep up the good work! Im enjoying following your thread!

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On 3/26/2017 at 10:03 PM, JZH said:

Blimey, that fork seal is...beyond words!  I think everything on this bike should be inspected--I wouldn't take anything for granted.  (Check inside the tyres!)

 

Ciao,

 

Hopefully, I guess I now opened the last parts that was meant to be opened which were the fork legs... I had the tyres removed once to get the wheels restored so no more water there anymore...

 

The only thing that I did not touch yet (of all parts that I got) are the brakes (front and rear) as well as the clutch system (master cylinder + line + receiver). Will flush any fluid (will report if I find any water in there) and upgrade to new braided lines anywhere. Probably try to get quickly some Brembo Red pads (front at least).

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Opened the cartridge yesterday and broken the compression and rebound stack:

 

large.20170402_181952_1024.jpg.4ecc47ce6611670c75217e7043e7f500.jpg

 

large.20170403_081939_1024.jpg.ddfa694b05584fdb1eb6a752da3cdd59.jpg

 

Compression stack is on top, rebound on the bottom.

 

Got some questions for the suspension gurus here:

 

Where is the compression stack? C5 to C7 or should I include C3 and C4 (to replace with Racetech recommended tapered stack)?

Same for rebound: I would say stack is from C4 to C8 included but I am not sure I should count C9 to C12 as part of the rebound stack.

 

For the records:

C5, R7 and R8 are ID 6mm, OD 17mm, width 0.15mm 

C6, C7, R4, R5 and R6 are ID 6mm, OD 17mm, width 0.10mm

 

Thanks a lot in advance.

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5 hours ago, bdouvill said:

Where is the compression stack?

Strictly speaking, the comp stack is C4-7.

 

C3 is a spacer, C4 is the all important clamp shim which looks nothing but actually influences overall stiffness as it defines the fulcrum against which the other shims bend.

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2 minutes ago, RC36Rider said:

Strictly speaking, the comp stack is C4-7.

 

C3 is a spacer, C4 is the all important clamp shim which looks nothing but actually influences overall stiffness as it defines the fulcrum against which the other shims bend.

 

So I assume that - let say I will go for Racetech C32 tapered stack - that I should put this stack between C3 and C8, right?

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5 hours ago, bdouvill said:

Same for rebound:

 

Same story, R9 is the clamp shim.

 

The rest are spacers which you can add or remove depending on actual stack height. Their function is to make sure you don't run out of thread when tightening the nut.

 

The RT instructions mention this but if you're like me, you'll only understand them fully AFTER you're done. :goofy:

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3 minutes ago, bdouvill said:

I assume that - let say I will go for Racetech C32 tapered stack - that I should put this stack between C3 and C8, right?

 

Correct. 

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If I got it well, C4 to C7 will flex when the fork is compressing when C3 is too thick to bend. Same story on rebound, R4 to R9 will bend as well when R10 to R12 are too thick (on purpose) and are just here as spacers. Am I right?

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Awesome work bdouvill, learning a lot reading this rebuild thread!

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2 hours ago, bdouvill said:

If I got it well, C4 to C7 will flex when the fork is compressing when C3 is too thick to bend. Same story on rebound, R4 to R9 will bend as well when R10 to R12 are too thick (on purpose) and are just here as spacers. Am I right?

 

Almost correct. 

 

The clamp shims do not actually flex either because their backs are fully supported by a wide, thick "spacer" but they are an integral part of the shim stack definition. 

 

Wider and/or thinner clamp shims make the whole stack stiffer and, conversely, narrower and/or taller make it softer.

 

I guess you got the idea right but did not express it completely correctly. 

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Which oil grade should I use? My local shop should have Motul Factory Line in 10W, 7.5W, 5W and 2.5W. 

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Stock is Showa SS-7 which is a 5W. I'd stick with that viscosity grade.

 

Nothing wrong with Motul of course.

 

Edit: In case, you are not entirely happy with your shim stacks and begin to tinker, do stick with the exact same oil, though. There is really no need to introduce an unknown variable in the equation.

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Ordered Honda inner and outer bushings from CMS, plus missing bolts here and there. Also ordered oil and dust seals from Louis.de, together 41mm oil seal driver and 1L of Motorex fork oil. Got to wait until all of this come to my place now. 

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  • 2 weeks later...

A quick update. I received almost everything to rebuild the fork, but not all, so I still have to wait 😞

4 shims are missing from my order...

 

Here is a comparison of original and modified shim stacks for compression first then rebound:

 

large.20170415_143533_1024.jpg.b858733013eafcfe90614117f5c67d3c.jpg

 

large.20170415_144737_1024.jpg.f8523f45910fc3eb358cc84cd259f66c.jpg

 

For the new rebound stack, I will re-use the 2 0.15mm shims for a total of 5 (the 2 darker shims on the left of the Racetech stack).

 

Here are the inner and outer bushings, oil seals, oil seal driver from Louis.de (20€ only, will let you know if that what worth the price) and 5W fork oil. Still missing the dust seals.

 

large.20170415_145611_1024.jpg.9842faa119d1dc44c317d302c27f9822.jpg

 

No special pics for the 0.85 kg/mm Racetech straight rate fork springs 😉

I got to buy a 32mm PVC pipe to cut some spacer since those springs are shorter than the Honda ones.

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And I have a question to help me understand how to cut the spacers. 

Which of those 2 settings is maximum spring preload? Left or right?

 

large.20170415_192814_1024.jpg.0c83687b0b5cfcf148e30afa1539ba58.jpg

 

I would say left but I am not sure... 😞

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