K&N Air filter and Bosch sparkplug page
Performance test report , M151A2 MOD
with ported, polished head and custom
header/ exhaust installed.
(Ron Rietfors is no longer doing any custom
Mutt Mods.)
with ported, polished head and custom
header/ exhaust installed.
(Ron Rietfors is no longer doing any custom
Mutt Mods.)
With the installation of the modified head and
exhaust complete it was time to go and drive the
Mutt. It started right up with no choke and
ticked way quietly and wonderfully smoothly at
about 500 rpm! I pulled out on the street and
what a difference, the throttle response was sure
and crisp, it snapped back down to the silky idle
as soon as I let off on the gas.With no hesitation
the Mutt accelerated much faster and easier
than before, the modified muffler has a low
slightly growling note but not too loud. The
engine was alive and pulled stonger than I ever
believed a Mutt engine could. I headed for my
test hill going throught the gears and there was
more and more power increase as the RPM's
went up, I went over 40 mph in third and it
reved like a race engine in a sports car , I
upshifted not because of running out of revs,
there was plenty more to be had ,but I didn't
want to float the valves. On the same steep hill
as the last test, I tried to go up it in forth but at
the very, very steep part had to down shift to
third, the Mutt then took off excelerating to 35
Mph in a hundred yards of steep climb with
only half pedal down, before these mods, it
would only hold its own on this hill at 25mph in
third and gas pedal floored!
On my daily drive to work , forth gear at 35
mph on the flat is just barely touching the gas
and its hard not to speed. All of this with much
less vibration that ever before, no shakey rear
view mirror like before!
On the hiway 65 Mph is no problem to get to
and hold, but I like to only drive the Mutt
around 55 and this M151A2 has unusually
quiet differentials anyway so the noise is very
low now for a Mutt. With the engine so smooth
it dosn't rattle the rest of the vehicle much .
I went out for another drive to the top of the
little mountian behind where I live to try out my
PRC-25 man pack radio on the 6 meter ham
band and the Mutt climbed the steepest part of
the hill in third and wanted to up shift to
forth,so I did at 32 mph and it pulled steady and
true up the hill between 32 and 35 mph with
very little gas pedal (about 1/4) . this hill was a
30 mph in third hill before the mods and the
Mutt had to work at it now it didn't even have
to try!!!
I haven't gone off road with this set up yet or
pulled the M416 trailer , so I will add to this
performance report as I find out more about
what Mutt can do with all this extra power!
From the Tests stock, to the performance with
K&N filter added and the the bosch platinum
four spark plugs, to the fully modified head and
exhaust, the increase in power seems to be
about 50% over all , making the Modified
engine about 100 -105 HP now. Not bad for
such a light vehicle and mine is a" heavy" Mutt
with ROPS and hard top.
Ron Rietors asked me to confirm or disprove
his claims about the performance increase with
this custom setup on the engine in as objective a
manner as I could and all I can say is that it is
more than I ever dreamed it would be in the
way of improved
drivability,acceleration,smoothness, idle quality
and pulling power.
Driving my stock M718 after a couple of days
with the newly powered up Mutt ( now nick
named" lightning") showed me how spoiled I
had become, it seemed really slow and rough,
and its a good stock runner and still big fun to
drive,just not as much fun as "LIGHTNING"
exhaust complete it was time to go and drive the
Mutt. It started right up with no choke and
ticked way quietly and wonderfully smoothly at
about 500 rpm! I pulled out on the street and
what a difference, the throttle response was sure
and crisp, it snapped back down to the silky idle
as soon as I let off on the gas.With no hesitation
the Mutt accelerated much faster and easier
than before, the modified muffler has a low
slightly growling note but not too loud. The
engine was alive and pulled stonger than I ever
believed a Mutt engine could. I headed for my
test hill going throught the gears and there was
more and more power increase as the RPM's
went up, I went over 40 mph in third and it
reved like a race engine in a sports car , I
upshifted not because of running out of revs,
there was plenty more to be had ,but I didn't
want to float the valves. On the same steep hill
as the last test, I tried to go up it in forth but at
the very, very steep part had to down shift to
third, the Mutt then took off excelerating to 35
Mph in a hundred yards of steep climb with
only half pedal down, before these mods, it
would only hold its own on this hill at 25mph in
third and gas pedal floored!
On my daily drive to work , forth gear at 35
mph on the flat is just barely touching the gas
and its hard not to speed. All of this with much
less vibration that ever before, no shakey rear
view mirror like before!
On the hiway 65 Mph is no problem to get to
and hold, but I like to only drive the Mutt
around 55 and this M151A2 has unusually
quiet differentials anyway so the noise is very
low now for a Mutt. With the engine so smooth
it dosn't rattle the rest of the vehicle much .
I went out for another drive to the top of the
little mountian behind where I live to try out my
PRC-25 man pack radio on the 6 meter ham
band and the Mutt climbed the steepest part of
the hill in third and wanted to up shift to
forth,so I did at 32 mph and it pulled steady and
true up the hill between 32 and 35 mph with
very little gas pedal (about 1/4) . this hill was a
30 mph in third hill before the mods and the
Mutt had to work at it now it didn't even have
to try!!!
I haven't gone off road with this set up yet or
pulled the M416 trailer , so I will add to this
performance report as I find out more about
what Mutt can do with all this extra power!
From the Tests stock, to the performance with
K&N filter added and the the bosch platinum
four spark plugs, to the fully modified head and
exhaust, the increase in power seems to be
about 50% over all , making the Modified
engine about 100 -105 HP now. Not bad for
such a light vehicle and mine is a" heavy" Mutt
with ROPS and hard top.
Ron Rietors asked me to confirm or disprove
his claims about the performance increase with
this custom setup on the engine in as objective a
manner as I could and all I can say is that it is
more than I ever dreamed it would be in the
way of improved
drivability,acceleration,smoothness, idle quality
and pulling power.
Driving my stock M718 after a couple of days
with the newly powered up Mutt ( now nick
named" lightning") showed me how spoiled I
had become, it seemed really slow and rough,
and its a good stock runner and still big fun to
drive,just not as much fun as "LIGHTNING"
Because of problems with one little fitting the
installation of these modified engine parts took
much longer than they should have and I was
afraid for a while that I was going to mess up the
head, but with adversity in the process, the
success of this project is all that much sweeter
and I'm loving how the M151A2 drives and
responds, even though I liked it before very
much now its a total pleasure to drive and the
effort I had to put into it makes it seem that
much better now that the project is completed
installation of these modified engine parts took
much longer than they should have and I was
afraid for a while that I was going to mess up the
head, but with adversity in the process, the
success of this project is all that much sweeter
and I'm loving how the M151A2 drives and
responds, even though I liked it before very
much now its a total pleasure to drive and the
effort I had to put into it makes it seem that
much better now that the project is completed
Happy Mutting,
John Cook , aka. otter k6ero
owner /editor of Muttmotorpool.com
John Cook , aka. otter k6ero
owner /editor of Muttmotorpool.com
I couldn't believe how much Better it performed!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!