Snowmobile World banner

1 - 14 of 14 Posts

·
Registered
Joined
·
2,303 Posts
Discussion Starter #1
Holly crap. Went out in my '89 Formula MX today. Had the motor rebulit last year, just finished breaking it in a couple rides ago, and man that thing is fast!!

I have a small yard, like not small small, but about an acre in size. Once I opened it up today and just gave 'er one shot wide open, hit about 7500 rpm and stayed there because the studs were trying to grip the now chewed up grass. Once it caught, after about 50ft, it took off and just about threw me off!!

Man, i cant wait to get out into some big fields!!



Who else has a formula mx?? How fast did u get it to go??
 

·
journeyman sled/motorhead
Joined
·
4,440 Posts
I have one,an 86 ,it has ran 90mph.I just put the motor from it into the 87 I picked up over the summer,much nicer sled.it is however tuned a lil' bit. :sarcasm:
 

·
Registered
Joined
·
2,303 Posts
Discussion Starter #3
Hey, was that speed wound rite out or did it still have more power left??
What kind of tweaks??
 

·
Registered
Joined
·
1,139 Posts
I bought a new MX in 1988 and it would pull 90 mph on very hard packed snow on a nice cold day.Those are awesome motors,use next to no oil and great gas mileage too.My dad sold his 92 with 23,000 kms on it.All we ever had to do to the engine was replace the headgaskets and the needles and seats in the carbs.
 

·
journeyman sled/motorhead
Joined
·
4,440 Posts
sled was clutched ,had a modified r.v.,and head mod. if you want to know specifics I will try and find out,this motor was originally built by dad back in '88,I don't know if he will remember and he never took notes.no at 90 it was done,that run was on radar.I will do some checking on it soon when I tear it down(the 86) but I think it was one tooth down on top.I smoked the 86 about 4 years ago and rebuilt it,this 87 I bought was the same way,they were running to many rpm's and the rods stretched,just remember they will not run on top with new sleds and you should be ok.the 86 had no tach on it when i blew it up.
 

·
Registered
Joined
·
978 Posts
my first sled I bought on my own was a 87 mx 462 and I loved it great power, would pull around 90mph aswell, kept it for 2 years, only thing with those models were no internal drive, so I changed alot of track clips over those 2 seasons. Traded for a 89 mach 1 witch was the first year for interal drive on the doo's
 

·
Registered
Joined
·
44 Posts
I have a 86 & yes they are fast and a lot of fun to ride if the trails aren't to rough. The only real problem I have is with the boots that seal out the snow around the tie rods. They do not hold up and it could be hazardous if you do not keep the snow and ice out.
 

·
Registered
Joined
·
2,303 Posts
Discussion Starter #8
Mines an '89. Does that mean mine would have the internal drive??
 

·
Registered
Joined
·
978 Posts
yep pretty sure, just look at the front of the rear suspention, you should see the rubber drivers built into the track and the sprocket meshing with them.
 

·
Registered
Joined
·
4,869 Posts
Originally posted by mx_462@Nov 19 2002, 09:37 PM
Mines an '89. Does that mean mine would have the internal drive??
Well that depends if it's the original track ???

All of my friends bought the kit to go internal drive on their MXs

They had 85,87,88,89 MXs
and they got the kit from kimpex :hallo1:

The MX and Plus went to internal drive in 1990 when they went to the 121" track

Yes the Mach in 89 had the internal drive with 121 but the MX and Plus had the outer drive 116 and 124" tracks :sly:
 

·
Registered
Joined
·
8 Posts
Man...you guys are old school....89???? Hope a boggy wheel didn't hit you in the leg. Last season, had a 1999 Polaris XCR 700 triple. Fastest sled I have ever owned, triple/triple/triple, pull the skis off the ground at 30 MPH....would smoke all you guys...

Sold, now have an 02 MXZ 800, should be even faster.... :devil:
 

·
journeyman sled/motorhead
Joined
·
4,440 Posts
well I see your from michigan,and I also see you think you can smoke us,which is a good thing if you can :) .but what if you cannot,will you get on here and tell all us that you were wrong?either way I will be riding around Irons, I look forward to you proving your claim this winter. ;)
 

·
Registered
Joined
·
2,303 Posts
Discussion Starter #13
Ya buddy from michigan. A boogey will hit me in the leg, when my feet are on the running boards, not in the track. '89's not that old. And i can keep the skis up til 30mph too there bud.

I bet i'd beat u to about 60mph too.

Triple/triple/triple

oh big man now.
 

·
Registered
Joined
·
16 Posts
I had a 90 MX. No modifications, ran good but the best I ever saw on the speedo was 80, whether hard pack or lake with an inch or two of snow. Reliable, low gas and oil usage but compared to modern machines, hard on the back. Heavy machine, performance in deep snow was poor, 90 Indy 400 would pass me every time with a ride that weighed 40lbs more than me. I'd beat him on hard pack though. His was stock also.
 
1 - 14 of 14 Posts
Top