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86 VFR700F Retool or therapy or both


tsmitty

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14 hours ago, tsmitty said:

Thanks Fastd for the insight but respectfully, if that's what needs to happen to get the engine running then I am done here! No way! I'll take the starter off and push start the bike...no...thats too hard too! 

 

Totally get you, I was just giving you (and of course anyone else reading this later) the information on what needs doing. 

 

Personally, if the electronics are otherwise good[1], although a pain in the **** because of the limited number of parts left I would try and get a good s/h '86 clutch because it is such a pain to have to get and swap so many parts. 

 

Personally I'm going going down the swap everything route with my '86 engine....but I have all the parts I need already and more importantly, I *don't* have an '86 ECU! 

 

[1] ie if the ECU itself is fine (which isn't guaranteed with the age of them), simple test of course being you can bump start it and it runs fine! 

 

 

 

 

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On 6/28/2023 at 3:24 PM, Captain 80s said:

 

It's actually the 86 that is unique, making the part even rarer.  The 87 outer housing shares the same part number with the 1990 VFR, even though the drawing on the parts diagram looks like the 86, not the 90. 

 

Ignore the drawings on the 'fiche as anything other than a "suggestion" of location! Never, *EVER* take them as any idea of what the part looks like! 

 

I've noticed on a *lot* of parts they've totally changed the part but re-used the earlier drawing. The only times it's vaguely accurate is when they've added a totally new part (as different to changed) and hence drawn something new. 

 

Quick example. https://www.bike-parts-honda.com/honda-motorcycle/750-MOTO/VFR/1989/VFR750FK/Frame/FRAME/13ML7G41/F__3100/2/10183 

 

Yeah, the 88-89 subframe looks *NOTHING* like that! 

 

Note it also goes the other way too with the earlier 'fiches updated to add in later options to allow one image to serve multiple bikes, again as an example. 

 

https://www.bike-parts-honda.com/honda-motorcycle/750-MOTO/VFR/1986/VFR750FG/Frame/REAR-FENDER/13ML7G41/F__2600/2/10147

 

'86 'Fiche, yet shows the 88+ sub-subframe as well as parts for the VFR750P! 

 

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Here is whats going to happen:

the 1986 clutch has two triggers protruding from it periphery. The 1990 has...who cares!

I'm going to use a bench grinder and grind all those little triggers off! except whats going to be needed.

I make my own two triggers out of mild carbon steel slightly taller and longer than the 1986 triggers I'm copying.

The two triggers will be brazed, welded, glued, duct taped...my wife's split pea soup, i don't care whatever will hold my two little triggers in place.

Then with a degree wheel on the crank, an ohm meter on a sensor, I will file the height, start-point, duration and end-point of my manufactured triggers to match the old broken stock clutch. Then get someone to test it on a working engine for me....lol 

See, I'm going at this as a machinist, all we are doing is reaching up with something that will tickle those two crank sensors.

I will make two slugs about the size and geometry of the two triggers from the 1986, bend a radius to match the clutch OD, find a specialist at sticking two pieces of metal together then its all hand work how much hand work depends on how much material i leave on the trigger blanks.

If there is an existing 1990 trigger in the way I will not remove it but build onto it either on the leading side or the trailing side or both using my already preformed trigger as filler. This, procedure to me isn't rocket science, i've worked at rocket science. If the idea actually works out is the question and the answer. 

This is all i got folks. The chassis, engine and electrical are all big ticket items and I don't have the cash or the agility i once did. So if it don't work its off to the front porch i go and happy retirement lol. 

 

Smitty

 

 

 

 

 

 

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12 hours ago, tsmitty said:

... Then with a degree wheel on the crank, an ohm meter on a sensor ...

If the coil is a coil I am not so sure you can detect the protrusions with a DC ohm meter. Try first. You may need to mimick whatever the excitation the ignition control unit uses. The F point should be 15 deg and full avanced 37 deg BTDC. The visible protrusion seen on your photo seems to be start at 50deg before T1 and end at 15 deg before T1.

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7 hours ago, rc24dk said:

The F point should be 15 deg and full avanced 37 deg BTDC. The visible protrusion seen on your photo seems to be start at 50deg before T1 and end at 15 deg before T1.

Thanks for the back-up plan. 

Its good I have a workable 86 clutch to compare from. My plan B is going to be, if the ohm meter doesn't work out is to create a garage machinist optical comparator lol,

Here we go...good camera with a 70-200 lens on a tripod directly in front of the crank. slip on 86 clutch and take a picture then slip on the 90 clutch and snap another pic. You then have two images at very high resolution that are exactly the same...exactly...except for those precious little bumps. I have photoshop and can overlay the images on top of each other and compare the two, honestly I'm guessing the picture method will be more accurate.

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Its raining, so I found amusement in making this little diagram:

image.png.9bc87fca6ad8b9475568c20b5777be38.png

Cyan is intake, green compression, red work and grey exhaust. "+" is where you actually need a spark. Based on that I would expect two opposed protrusions as the one visible on the photo earlier in the tread in order to generate sufficient pulses. As I understand Fastdruid the ECU is analogue. It could be fun (to me at least 🙂) to see an electronics schematic for that ECU black box to understand how the advancement works.

image.png

Edited by rc24dk
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If you have the Honda manual it gives some detail about how it works. spacer.png

 

1 and 3 are rear, 2 and 4 are front cylinders.

Essentially the pulse generator tells it to fire, the cam sensor tells it *which* one to fire. 

The manual says it's a microcomputer... I think that's somewhat over-egging it! 

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  • 2 weeks later...
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Finished making my comparing and measuring set-up. Time to plot out the stock clutch and see what need to happen to the 1990 clutch... 

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So here is the 1990 clutch. and the pictures are the only triggers that are going to come into play in this experiment, the other triggers will be removed. I'm going to fill the gap on each of these two sets of triggers, I have some 5/16 x 1/8 mild steel to profile, bend and fit into place between then TIG. What you have is a copy of the stock 1986 almost... the trigger height is slightly taller than stock and cane easily fixed with a file. This new trigger and its (exact)180deg counterpart will hit the senses 3deg sooner than the 1986's. I'll show you how I'll handle this. I'm guessing my set-up is within  >0.5deg from reading the scale, each devision is .010"

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Edited by tsmitty
doubled a picture
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As I said the now new 1990 triggers will hit the sensors 3degrees sooner than the 1986's do. Here is what that looks like on the scale. Not the best angle on the pic but basically I have to trim about .080 off the leading edges and add .080 on the trailing edges of the triggers. FYI degrees of rotation of both the 1986 and the 1990 triggers (dwell) is 35.5/36deg.. just different leading and trailing points.

I think this is all going to be doable, the TIG guy said he can button things up without introducing too much heat to the hardened insides.

We will meet again to talk about fillet sizes and locations and critical clearance location (at clutch basket behind triggers). The 1990 triggers are about .010 taller than the 86 is this even an issue? Think this shit will work?? I aint hatin this stuff...

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Regarding the height, just make sure there is ample clearance allowing for any possible "growth" of the material from heat.  I would knock it down a few thou when the mods are done to make sure.

 

And if you wanted to introduce any timing advance, now is the time.

 

This looks very doable!!

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I don't know about the timing change. I did a bolt-on 2deg timing advance for my 929 back in the day but honestly don't know if I'm comparing apples to oranges here. I'll just leave the question hang here a while as I create the trigger blanks.

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Sounds like you are inventing a whole new sideline business modifying later starter clutches to keep the 86 bikes on the road. Go fo it! 

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46 minutes ago, Terry said:

Sounds like you are inventing a whole new sideline business modifying later starter clutches to keep the 86 bikes on the road. Go fo it! 

No Terry, I'm just enjoying the process. If this does work, I hope someone can learn, copy and improve on this...that would be awesome! 

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I just know that when I pulled my 86's starter clutch apart (it was making some terrible noises) I had my heart in my mouth that I was going to find it horribly cracked (it wasn't). I am mighty impressed with your ingenuity to this point and wish you great success!

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Thanks a lot Terry! 

Someday I might just be able to hit that stator button. BTW I had to take that apart and fix that too! lmao

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2 minutes ago, rc24dk said:

The hub looks a bit higher. Will it interfer with the cover?

If I'm understanding you, the hub (clutch?) is just about exactly the same, the triggers are a tad taller than the 86 but can be dusted off with careful hand filing and measuring. 

I am using my original 86 FLANGE,STARTER CLUTCH  Honda calls it; so the clutch are very close to identical. 

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6 minutes ago, tsmitty said:

If I'm understanding you, the hub (clutch?) ...

What I meant is the "something" between the housing front surface (with the T and F marks) and the securing screw head. Maybe it's just a thick shim I was mistaking for a hub protrusion or such ...

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Started roughing the Trigger blanks, I'm using 1018 Carbon Steel Rectangular Bar, Unpolished (Mill) Finish, Cold Finished Temper, ASTM A108, 1/8" Thickness, 5/16" Width, 12" Length

https://www.amazon.com/dp/B000H9P176?psc=1&ref=ppx_yo2ov_dt_b_product_details

 

So I'm looking in the garage for something to bend the stock to try to match the clutch minor OD and found this...

 

Thank you God it turned out perfect...

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I can't tell you how many times I walk around my shop or the shop at work looking for something that is the right diameter 

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