Performance report on K&N Air filter
modification for the M151 MOD &
Bosch Platinum 4 Spark plugs
modification for the M151 MOD &
Bosch Platinum 4 Spark plugs
The Mutt comes alive!
The first thing I noticed when I took the wire mesh and horse
hair out of the air cleaner top was that there was very old dust
and dirt in there! All cleaned up, I set the K&N air filter on
the top flange and saw that it was exactly the same diameter.
I used # 6 stainless steel screws, a 3/32 " drill bit for drilling
through and then a 1/8" drill bit on the new filter flange for the
screws to not bind on it!
I had to be very carefull to not run off the inside edge of the
Air cleaner to when drilling , I made one mistake, which I
filled with epoxy.
The K&N filter came with Rubber gaskets pre-glued to the
flange ,I removed the gasket on the side facing up in the
photos and then removed the adhesive that was left behind
with paint thinner. After drilling as per Ron Reitfors
instructions I got all of the metal shavings out of the filter top
and from around the flange! then with the K&n filter screwed
inplace was ready to reassemble the Mutt air cleaner and go
for a test drive.
hair out of the air cleaner top was that there was very old dust
and dirt in there! All cleaned up, I set the K&N air filter on
the top flange and saw that it was exactly the same diameter.
I used # 6 stainless steel screws, a 3/32 " drill bit for drilling
through and then a 1/8" drill bit on the new filter flange for the
screws to not bind on it!
I had to be very carefull to not run off the inside edge of the
Air cleaner to when drilling , I made one mistake, which I
filled with epoxy.
The K&N filter came with Rubber gaskets pre-glued to the
flange ,I removed the gasket on the side facing up in the
photos and then removed the adhesive that was left behind
with paint thinner. After drilling as per Ron Reitfors
instructions I got all of the metal shavings out of the filter top
and from around the flange! then with the K&n filter screwed
inplace was ready to reassemble the Mutt air cleaner and go
for a test drive.
I fired up the Mutt for a test drive.I already had it running good in stock condition, but she started
even faster then normal and had a nice smooth idle,I let her warm up a minute and off we went.
WOW !!! did the excelleration smooth out , low Rpm throttle respone was much better and as the
RPM's went up so did the feeling of the engine being free to breath. This is a subjective report not a
scientific study,but on a level road I drive every day The mutt was going 42 Mph with the same
amount of gas pedal as it was normally going 35 mph.
I took each gear to five Mph over the recommended speed and there was only a feeling of increasing
power.
I found that I could take the steepest hill in town at 22 mph in third gear while going up it with no
hesitation and half pedal on the gas. Below 15 in Third was bottom end and I had to down shift. The
Mutt was real happy going 55Mph on the flat and had lots of pedal left.
Mostly the engine was real happy, like somone who had just gotten over a chest cold and could breath
easy again.
The Mutt seamed to have about 10% more low end power but its power curve was extended and as
rpm went up so did the power increase! At cruising speed I would say it had 15% to 20% more power
As it got up to top RPM for each gear it felt like a turbo was cutting in. I never expected so much from
just having a better breathing air filter.
The engine still looks stock and for $50 for the filter (million mile warranty) and an hours work I think
its the one best thing that can be done to have a more responsive, stronger Mutt engine. I saved all the
parts I removed from the air cleaner and this is the good kind of mod for a historic MV, it can be
returned to a stock state at any time in the future with no harm done!
I let the engine cool and went to the next step , Bosch Platinum+4 spark plugs
even faster then normal and had a nice smooth idle,I let her warm up a minute and off we went.
WOW !!! did the excelleration smooth out , low Rpm throttle respone was much better and as the
RPM's went up so did the feeling of the engine being free to breath. This is a subjective report not a
scientific study,but on a level road I drive every day The mutt was going 42 Mph with the same
amount of gas pedal as it was normally going 35 mph.
I took each gear to five Mph over the recommended speed and there was only a feeling of increasing
power.
I found that I could take the steepest hill in town at 22 mph in third gear while going up it with no
hesitation and half pedal on the gas. Below 15 in Third was bottom end and I had to down shift. The
Mutt was real happy going 55Mph on the flat and had lots of pedal left.
Mostly the engine was real happy, like somone who had just gotten over a chest cold and could breath
easy again.
The Mutt seamed to have about 10% more low end power but its power curve was extended and as
rpm went up so did the power increase! At cruising speed I would say it had 15% to 20% more power
As it got up to top RPM for each gear it felt like a turbo was cutting in. I never expected so much from
just having a better breathing air filter.
The engine still looks stock and for $50 for the filter (million mile warranty) and an hours work I think
its the one best thing that can be done to have a more responsive, stronger Mutt engine. I saved all the
parts I removed from the air cleaner and this is the good kind of mod for a historic MV, it can be
returned to a stock state at any time in the future with no harm done!
I let the engine cool and went to the next step , Bosch Platinum+4 spark plugs
Click on the
spark plug
picture to read
about the
modified Bosch
plugs and how
much more they
did for the Mutt!
spark plug
picture to read
about the
modified Bosch
plugs and how
much more they
did for the Mutt!