Docstoc

V45 Magna Cam Chain Tensioner Mod

Document Sample
V45 Magna Cam Chain Tensioner Mod Powered By Docstoc
					ANDY'S CAM CHAIN TENSIONER MODIFICATION.DOC                                                                           JUNE 9, 2011


Cam Chain Tensioner Modification

After 27 years under tension the cam tensioners were no longer strong enough to stop the cam chain from
slapping and creating loud ticking noises as it rotated at idle. It stands to reason that the action was even
worse at higher revs but this could not be heard at riding speed because of the wind noise and riding
position.

Before you plunge into this, poorly adjusted/synched or dirty carbs can result in unequal firing of the
cylinders resulting in uneven action of the cam chains causing the chain to go slack-tight-slack- tight and
slap against the chain guide making a sound like loose valves.

Replacement tensioners are not available from Honda – nor were springs. Additionally, they were not
available from aftermarket sources. Salvaged tensioners could be found but there was no way to determine
if they were in better condition – i.e. stronger.

The picture shows the extent of the disassembly required by the three projects:
                             • dual gas tank reconditioning,
                             • carburettor rebuilding,
                             • Cam chain tensioner modification.

Most of the rear end disassembly was required to be able to remove the auxiliary gas tank which can only
be removed through the space covered by the inner rear fender.

During reassembly, all the gas lines will be replaced with new ones and the single gas filter will be
augmented by a second one to increase the protection for the carburetors and the fuel pump. I DO NOT
want to be repeating this!!!


                                                    1985 VF750C-E Honda Magna




Z:\Data Files\Motorcycle\Honda Magna (1985) VF750C\Cam Chain Tensioners\Andy's Cam Chain Tensioner Modification.doc    Page 1 of 6
FEEL FREE TO USE THIS TO YOUR OWN BENEFIT – BUT IT REMAINS MY PROPERTY.                                             JUNE 9, 2011


Cylinder Bank 1-3



                      Clutch
                   Hydraulic Line                                                            Top cylinder bank (1-3) after the
                                                                                             cover, sub cover, cam chain
                                                                                             cover, and oil crossover tubes
                                                                                             have been removed.

                                                                                             Note the plastic tie on the rear
                                                                                             cam sprocket. This is used to
                                                                                             ensure that the cam chain does
                                                                                             not slip over a tooth which would
                                                                                             affect the valve timing.
   Zip tie to maintain
          timing                                                                             There is no tie on the front cam
                                                                                             sprocket because the cam must
                                                                                             be removed to allow the tensioner
                                                                                             to be removed.

                                                                    Main Wiring              Torque on all head bolts had to
                                                                     Harness                 be backed off and then just
                                                                                             snugged up to avoid warping the
                                                                                             head since the centre bolts were
removed.




The top of the cam chain
tensioner can be seen below the
cam chain between the two
sprockets.                                                                Zip tie in place

Note the paint marks on each cam
sprocket and chain links. These
are used to ensure that the front
cam goes back in exactly the
same orientation.

Timing mark locations were also
noted before any disassembly.




                                                                                                                       Page 2 of 6
FEEL FREE TO USE THIS TO YOUR OWN BENEFIT – BUT IT REMAINS MY PROPERTY.                                            JUNE 9, 2011


Cylinder Bank 2-4




                 Fan hanging on
                  bungee – later
                    removed.                                              This shot shows the front cylinder bank after the
                                                                          cover has been remover and has the cam cover,
                                                                          and oil crossover tubes in place. This bank of
                                                                          cylinders does not have a sub-cover.


                                                                          Ignore the yellow extension chord.




This shot shows the cylinder bank after the cam
cover, oil cross-over tubes and front cam caps have
been removed.

Note the paint marks on front and back cam
sprockets and chain links. The plastic tie on the
rear cam sprocket is barely visible right at the top of
the picture.

There is no tie on the front cam sprocket because
the cam must be removed to allow the tensioner to
be removed.




                                                                                                                     Page 3 of 6
FEEL FREE TO USE THIS TO YOUR OWN BENEFIT – BUT IT REMAINS MY PROPERTY.                                        JUNE 9, 2011




                                                                                          This shot shows the top cylinder
                                                                                          bank after the front cam and the
                                                                                          tensioner tower has been
                                                                                          removed.

                                                                                          The cam chain is pulled up and
                                                                                          tension is maintained on the
                                                                                          bottom end using a bungee
                                                                                          cord.

                                                                                          Note the yawning chasm just
                                                                                          begging to have oily stray nuts
                                                                                          and washers dropped into it like
                                                                                          stones down a well.




                                                                                   Cam Slipper            Cam Chain
These are the parts removed in                                                                              Guide
order to remove the tensioner
tower (outside the tray) which has
been partly disassembled by
removing the chain slipper (laying
on top of the other parts) to allow it
to come off the cam chain.                                                    Oil Crossover
                                                                                  Tubes
The wire sticking out of the
tensioner tower is bent into an “L”
shape and used to lock the arm                                Cam Tensioner
into place against the tension of the                            Tower
spring.                                                                                                     Front Cam and
                                                                                                               Sprocket
To avoid ANY possibility of mixing
parts that shouldn’t be mixed, I
didn’t take the banks apart at the
same time.




                                                                                                                 Page 4 of 6
FEEL FREE TO USE THIS TO YOUR OWN BENEFIT – BUT IT REMAINS MY PROPERTY.                                     JUNE 9, 2011




                                                                                        Cam Chain Tensioner Tower as
                                                                                        removed from the bike

                                                                           Tensioner
                                                                          Locking Tab




                                             Tensioner
                                            Spring Tube




Disassembled Cam Chain
Tensioner Tower with marks to
show the relocation of the spring
anchor.




                                                                                                              Page 5 of 6
FEEL FREE TO USE THIS TO YOUR OWN BENEFIT – BUT IT REMAINS MY PROPERTY.                                              JUNE 9, 2011




                                                                                              The rolled over end of the Factory
                                                                                              pin was ground back to the hole
                                                                                              diameter to allow the pin to be
                                                                                              punched out and reused.



                                                                             New Pin
                                                                             Location
               Action Line of
                Tensioner
                   Spring                                           Factory Spring
                                                                     Anchor Pin




Modified and reassembled tensioner
tower ready to be reinstalled.

The original pin was reused in the
new location and welded to the
tensioner arm. The weld was
ground down to the original
thickness of the rolled over pin end.

Yes, I know the weld looks crappy –
that welder had a jerky wire-
advance system. That’s my excuse
and I’m sticking to it!

Re-installation is a fairly predictable
reversal of the removal EXCEPT for
the torquing of the different sized
bolts. Look up the torques and:
1. torque ALL bolts to the torque for
   the smallest diameter then move
   up a size, and
2. torque ALL the size and larger                                             New Action
   bolts to that torque.                                                     Line of Spring
3. repeat until all sizes have been
   torqued.

This process minimizes any chance of warping the heads.

Happy in Hondaland,

MagnAndy
Brampton, Ontario, Canada

                                                                                                                       Page 6 of 6

				
DOCUMENT INFO
Shared By:
Categories:
Tags:
Stats:
views:1388
posted:6/10/2011
language:English
pages:6
Description: Overview of a modification to a 1985 Honda V45 Magna motorcycle