vfr700 camshaft rocker arms variations

I am working on a set of cylinder heads from an 86 vfr700. Several years ago I did similar work on a 87 vfr700. I was hoping to use some of my spares on the '86. However it seems there were variations to the heads and rockers so parts are not interchangeable. This probably also applies to 86-87 RC24 models.


1) cam speed sensor / pulse sensor
The front head on an 86 vfr700 has an addition hole to accommodate the cam pulse sensor. This is gone on the 87, and possibly late 86 models as well ?

2) tappet screw adjusters
On the 86 head, the tappet screws are held in place be the rocker arm retainer plate.
The 87 heads appear to have the tappet screw adjuster press-fit into the cylinder head. A drift & hammer is required to install them. This is description from the factory service manual:

IMG_20200406_094453-2 by chuntera posted Apr 6, 2020 at 12:29 PM

3) rocker arm retainer
The rocker arm retainer plates hold the rocker arms at correct alignment, so end of the rocker is always in contact with the valve stem. AFAICS there are three variations of the retainer used to hold rocker arms in place
- The early 86 model has a retainer plate held by two bolts.
- Later 86 models added a retainer spring and spring holder to the retainer plate
- 87 models use two metal plates (that bridge the spark plug well) to hold the rockers arms

This is table from factory service manual:

20200406_094150-2 by chuntera posted Apr 6, 2020 at 12:29 PM

Some example photos I collected online:

- early 86 model with no retainer springs on the rocker arms. You can see one of the bolts holding the retainer plate.

IMG_20191214_162848 by chuntera posted Apr 6, 2020 at 12:17 PM

- later 86 model added retainer springs that clips onto rocker arm just forward of the tappet locknut.

Ebay-86vfr-rocker-2 by chuntera posted Apr 6, 2020 at 12:18 PM

- 87 retainer assembly (camshafts removed)

Ebay-87vfr-rocker-2 by chuntera posted Apr 6, 2020 at 12:18 PM

 

Interesting, I'm gonna have to take a look. I've got 2 86 engines (one 700, one 750) that will be getting clearance checks soon. But I think all 4 of my 86 VFRs are early.

And my SM is 86 only, I'll take a look in there too.

 

I think you will find the spring plates from 87 can be used on the 86 heads as long as you have the two studs and both plates. The mounting holes look like they are in the same place as the bolts for the earlier plates.

Here's the parts diagram
https://partsfinder.onlinemicrofiche.com/gpbikes/showmodel.asp?type=13&make=hondamc&a=97&b=6&c=0&d=1987%20VFR700F2%20INTERCEPTOR%20700%20CAMSHAFT%20W/%20VALVE

Below are two pictures of the head with the wire springs (my project bike) and one without (spare heads bought off ebay).
I got the spare head and thought someone had removed the springs but maybe not. It must be an early 86 head.

Interesting when looking at the Honda online parts lists has different series of engine numbers which I have listed below.
The rockers are the same for 86 and 87. 14611-ML7-010 ARM, VALVE ROCKER

For the 700

The wire rocker springs are listed at.
14617-ML7-000 SPRING, ROCKER ARM (USE FROM ENGINE SN 2000197)
The sheet steel springs were used for the 87 F2 model.

The tappet screw was changed between the 1986 and 87 model years.
1986 90012-ML7-003 SCREW, TAPPET ADJ.
1987 90012-ML7-013 SCREW, TAPPET ADJ.

For the 750 (no 87 model year listed, only offered the 700 F2 in 87, at least in Canada)

The wire springs were used from engine 2007522 (no springs before this)
14617-ML7-000 SPRING, ROCKER ARM (USE FROM ENGINE SN 2007522)

the tappet screws are shown to change during production

90012-ML7-003 SCREW, TAPPET ADJ. (USE FROM ENGINE SN 2007520) (this does not make so much sense to be one engine apart. I assume this is engine numbers prior to this number)
90012-ML7-013 SCREW, TAPPET ADJ. (USE FROM ENGINE SN 2007521)

I'm wondering if the rockers can be run without the rocker springs? Honda must have had a rational for fitting them on later versions of the engine but if the early engines run without retrofit what purpose do they serve? Noise reduction?.