Differences between 86 and 88

[FMFWarrior21]

What were the major differences between an 1986 250r and a 1988 250r and which one makes a better mxer?

[JTRtrx250r]

88-89 frame geometry and is the biggest diffrence, 86-87 swinger is an inch longer than 88-89 style, the 88-89's aarms mount an inch forward to compensate the shorter swinger and the 88-89's turn/corner better w/ the shorter swinger,86 swingarm skid mounts are diffrent than 87-89

* most mx guys w/ 86's get a -1 swingarm and +1 froward aarms to make up the 88-89 geometry*

86 is the strongest frame of all the yrs(and heaviest), better gusseted w/ extra frame support(stock)and beafier motor mounts, also front bumper mount is a little diffrent but they all mount the same, 87-89 frames(open frame tubing) rust out and fill w/ sediment from the inside quicker than 86 also

87thru 89 are long-rods and make better torque for mx than the 86 short-rod(revs a tad quicker) , the 89 clutch was best also, but the 86 airbox boot is better, 87-89 have a resinator that can cause air leaks

the front spindals on 86-87 are straight while the 88-89 spindals are tapered(for better side-load on bearings), 88-89 front rotors only use 3 bolts , 86-87 uses 4,


Im sure ther are a few others that Im spacin' on but others can help, hope I made some sence...:tired:

[Rich250RRacer]

Are you sure the a-arms are an inch forward? I've only owned one 88 model so I never really paid much attention, but if you look at the Honda specs for the quads, the 88-89 wheel base is about an inch or so shorter than the 86-87 model, which would be justified by the shorter swingarm. If the a-arms were an inch forward, wouldn't the wheel base be the same?

[TheFontMaster]

Will an 86/87 swingarm bolt up to a 88/89 style frame?

[zedicus00]

with sum modding the swinger will bolt up, u r better off finding a used afteermarket swinger though. the 88-89 swinger is actually 2 inches shorter then the 86 - 87 one and the 88-89 does hav 1 inch forward a arms so yes there is only one inch difference in the wheelbase and yes 88-89 a arms are 1 forward.

[JTRtrx250r]

Originally posted by Rich250RRacer
Are you sure the a-arms are an inch forward? I've only owned one 88 model so I never really paid much attention, but if you look at the Honda specs for the quads, the 88-89 wheel base is about an inch or so shorter than the 86-87 model, which would be justified by the shorter swingarm. If the a-arms were an inch forward, wouldn't the wheel base be the same? Yep..(Zed covered it)

But what Ive never understood..is why ppl w/ 88-89s still buy the +1 forwards:p :confused: :D :blah:

[beerock]

Originally posted by JTRtrx250r
88-89 frame geometry and is the biggest diffrence, 86-87 swinger is an inch longer than 88-89 style, the 88-89's aarms mount an inch forward to compensate the shorter swinger and the 88-89's turn/corner better w/ the shorter swinger,86 swingarm skid mounts are diffrent than 87-89

* most mx guys w/ 86's get a -1 swingarm and +1 froward aarms to make up the 88-89 geometry*

86 is the strongest frame of all the yrs(and heaviest), better gusseted w/ extra frame support(stock)and beafier motor mounts, also front bumper mount is a little diffrent but they all mount the same, 87-89 frames(open frame tubing) rust out and fill w/ sediment from the inside quicker than 86 also

87thru 89 are long-rods and make better torque for mx than the 86 short-rod(revs a tad quicker) , the 89 clutch was best also, but the 86 airbox boot is better, 87-89 have a resinator that can cause air leaks

the front spindals on 86-87 are straight while the 88-89 spindals are tapered(for better side-load on bearings), 88-89 front rotors only use 3 bolts , 86-87 uses 4,


Im sure ther are a few others that Im spacin' on but others can help, hope I made some sence...:tired:

damn nice job jt

the 86-87 rear motor mount/swingarm is different then the 88-89
the 86-87 has a spot in the middle for a motor mount where as the 88-89 has no space for a motor mount, the motor mount is welded to the frame instead.

The foot peg mounts are different on a 86-87 compared to a 88-89

the 86-87 have a weak front shock cross bar piece the 88-89 is gusseted and is stronger.

The 86 transmission has a 1 less tooth on 5th and 6th on the counter shaft compared to the 87-89 transmissions, this means you can get more top speed out of a 86 but 2nd gear is weak on the 86 tranny. It also means that the 87-89 tranny have a smoother transition from 4th to 5th

The cylinders and heads are different too. the 86 style cylinder has no intake bridge, i believe 87-89 all have intake bridges. the heads have different sized domes.

the wrist pin on a 86 is 5mm higher then the 87-89 honda did this to increase reliability. Because of this change racers are able to use a 86 piston with a 87-89 crank, install a 5mm cylinder bas spacer plate. this increases volume in the crank case and gives the motor a smoother wider powerband.

im not gonna think no more now...

[beerock]

Originally posted by JTRtrx250r
Yep..(Zed covered it)

But what Ive never understood..is why ppl w/ 88-89s still buy the +1 forwards:p :confused: :D :blah:

+1 arms are 88-89 geom, when you put +1 on a 86 it makes it a 88-89 geom.

i run a -1 3/4" laeger swinger and its shorter then the 88-89 by 3/4" ive put them side by side. so maybe its 2 3/4"?

[Rich250RRacer]

Originally posted by TheFontMaster
Will an 86/87 swingarm bolt up to a 88/89 style frame?

If you really want to run the 86-87 arm on the newer chassis, just get the spacer tube from an 86-87 and cut the motor mount ears off.

[JTRtrx250r]

Originally posted by beerock
damn nice job jt

the 86-87 rear motor mount/swingarm is different then the 88-89
the 86-87 has a spot in the middle for a motor mount where as the 88-89 has no space for a motor mount, the motor mount is welded to the frame instead.

The foot peg mounts are different on a 86-87 compared to a 88-89

the 86-87 have a weak front shock cross bar piece the 88-89 is gusseted and is stronger.

The 86 transmission has a 1 less tooth on 5th and 6th on the counter shaft compared to the 87-89 transmissions, this means you can get more top speed out of a 86 but 2nd gear is weak on the 86 tranny. It also means that the 87-89 tranny have a smoother transition from 4th to 5th

The cylinders and heads are different too. the 86 style cylinder has no intake bridge, i believe 87-89 all have intake bridges. the heads have different sized domes.

the wrist pin on a 86 is 5mm higher then the 87-89 honda did this to increase reliability. Because of this change racers are able to use a 86 piston with a 87-89 crank, install a 5mm cylinder bas spacer plate. this increases volume in the crank case and gives the motor a smoother wider powerband.

im not gonna think no more now... Damn...nice job Bee";) :D

[JTRtrx250r]

Originally posted by Rich250RRacer
If you really want to run the 86-87 arm on the newer chassis, just get the spacer tube from an 86-87 and cut the motor mount ears off. yeah...this is true, but you'll wanna make a rear motor mount off the frame which requires fabing/welding(very simple )

[Rich250RRacer]

There's already a mount for the top hole and I don't believe 88-89 run one at the rear bottom, unless it's an aftermarket chassis. So you shouldn't have to add anything unless you want to add a lower mount for strength.

[JTRtrx250r]

Originally posted by Rich250RRacer
There's already a mount for the top hole and I don't believe 88-89 run one at the rear bottom, unless it's an aftermarket chassis. So you shouldn't have to add anything unless you want to add a lower mount for strength. LOL..Im a dumbass!:D :o I was thinking backwards, was thinking of it being an 88-89 swinger on a 86-87:o :p I was very tired when I posted that:rolleyes: :blah:

[Rich250RRacer]

Originally posted by zedicus00
with sum modding the swinger will bolt up, u r better off finding a used afteermarket swinger though. the 88-89 swinger is actually 2 inches shorter then the 86 - 87 one and the 88-89 does hav 1 inch forward a arms so yes there is only one inch difference in the wheelbase and yes 88-89 a arms are 1 forward.

Ok, I had to check this out myself, since I still had my doubts, so I found an 88 chassis and compared it to my spare 86 chassis. Measuring from the center of the swingarm bolt to the upper rear a-arm mount, the 86 and 88 chassis are the same, give or take a 16th of an inch. This is the only logical place to measure from, since we know the location of the swingarm mount did not change from year to year. Maybe the actual placement of the ball joints is an inch farther forward, I haven't set early and late arms side by side yet. If this not correct, where should the measurements be taken.

[beerock]

1" is in the angle of the arms.....

[Rich250RRacer]

Originally posted by beerock
1" is in the angle of the arms.....

So there really isn't any difference in chassis geometry itself, it's all made up in the A-arms. I thought this was the case. The mounts themselves are actually in the same place all years. Thanks beerock!