'87 motor

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tracetrimble
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Joined: November 5th, 2008, 7:42 pm

'87 motor

Post by tracetrimble »

The '87 motor is the most powerful, right? Good choice for a beercan? Is the tranny wide or close ratio?
Trace
'00 KTM 380EXC, and looking for the right AF project.
JBaze

Post by JBaze »

I always felt the 85 or 86 had a hell of a lot more hit than the 87. It does have the wider gear box but I found the 87 alot more ridable than the 85 or 86. The 89-93 had almost electric type of power to me, 94 to 01 were imo the best. Mass managable power and a wide box. The 87 is just fine also to me though.
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JR650
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Post by JR650 »

ive been wrong before, but im pretty sure the 85-86 was the meanest too. tranny is wide ratio in 85-86. im using an 85 for my gen 3, 87 is long rod too. good choice to me. pretty sure the tranny is wide ratio till 89?.
00 XR650R street legal SM
02 250/500
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Roostius_Maximus
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Post by Roostius_Maximus »

Cauton yourself with pipe fitment, my Fatty on an 87 long reed jug will rub at the reed if not clearenced in a gen3
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caseyracing222
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Post by caseyracing222 »

isnt there a swingarm bolt issue on the af's with the older motors too?
-Jake

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iggys-amsoil
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Post by iggys-amsoil »

caseyracing222 wrote:isnt there a swingarm bolt issue on the af's with the older motors too?
Yes. 85-88. New spacers in the cases need to be made as they only come with new cases. :?

and ya the pipe can rub the reed block or in my case the lower bolt head. I had my welder heat it up and push it in a little.

Now I either need to put the stock triple clamps on or have him do the same thing where the front tire rubs :x The eight year old pipe didn't rub, well after yesterday it does but bearly.
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jbird_710
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Post by jbird_710 »

I'm not sure if the tranny is considered a wide or close ratio; but, back in '87, Honda offered a wide ratio gear set for it. You had to buy it separately from the stock CR500 and install it. Ihave read from others doing AF conversions that the hole in the back of the earlier cases where the swingarm shaft goes is smaller than on the new cases and has to be enlarged to accept the AF shaft.
'87 CR500R / (2) '01 CR500R / '02 MPS CR500R AF / '06 XR650R / '06 XR650L / '01 XR400R / '01 FLHTCUI / '04 CRF 450R / '84 CR500R / '89 Transalp /'05 CRF450X / '02 XR200R
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kkvslayer
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Post by kkvslayer »

The case bushings are no big deal they can be bored 2mm larger or you can have some new ones made up,Mike bored mine for 40$
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1994 Heartless CR500R
1986 KX500
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dannygraves
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Post by dannygraves »

'87 is a kickass motor... wide ratio, long rod, but still has the sick porting like the '85-'86.
The rear bushings need to be bored or replaced with once from your a/f take out motor. coolant hose setup needs to be modified and as roostius mentioned the reeds are longer, so the reed bolts are furter back and can interfere with pipe fitment. plus you have to buy a newer kicker or struggle with the a/f take out kicker.
all in all the pre '89 motors are more work to convert and the performance difference between that and a '90+ is marginal, just more hit, less control.
'09 kx450f 4-Poke
Gen-4 trail bike --SOLD--
Gen-3 badass trail/mx bike --SOLD--
Gen-1 built dunes bike --SOLD--
'05 klx110 --SOLD--
'95 pw80
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87CR500Rider
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Post by 87CR500Rider »

It's a good balance between the arm ripping 85/86 and the later "sleeper" engines. I own an 87' and a spare 87' engine. I love 'em. They ALL make more power than you can use on a MX track.
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Roostius_Maximus
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Post by Roostius_Maximus »

I just built one for my AF with 87 cases, 90 crank? 87+88 trans parts, 94 clutch system, and a jug that honda made to fit it off of the 89+ casting with short reed, small sleeve, very dang close to '87 porting, tall rear studs, dual water outlet, dual drain plugs, and unfortunately scallops, but it was new, surface rusty at standard bore for 30$ on ebay, and i indexed the kicker spindle to use the '03 250 kicker and not have it rub the pipe
tracetrimble
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Post by tracetrimble »

Thanks for all the replies. I bought it. The bike is in pretty good shape overall and came with a clear title, but I couldn't get it started. It has spark and 130 psi compression, so probably time for a topend and maybe reeds. The guy apparently needed cash, and sold it to me for $575.

Based on the additional modifications & hassle, I'll probably fix this one up as a vintage and keep looking for a newer motor. Plastic is good, radiators are perfect, gold wheels are true, etc.
Trace
'00 KTM 380EXC, and looking for the right AF project.
JBaze

Post by JBaze »

Thats a great deal man. 1987 was my all time favorite 500. I wanted to get one and put the USD forks on it to replicate the works bikes of the time. Congrats
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Nodge
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Post by Nodge »

dannygraves wrote:' or struggle with the a/f take out kicker.

85 motor + shaved head + 250 kicker = Next to theft proof.
Anybody got a kicker for sale? :D
Yah, I'm from Saskatchetoon!

MRE 02 250/500 conversion, pulse injector, twirp porting, coolhead, MRE ignition, blah blah blah blah... www.millarengines.com
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Roostius_Maximus
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Post by Roostius_Maximus »

I've got the '03 250 kicker lever, the 87-01 tooth kicker spindle, '88 250 ignition and its a dream. Its even nicer once you pop the decompressor, it'll start with 1/2 a kick no prob. Feels like a gasgas 250 if you've ever tried one.

The 250 kicker never worried me, its very close to an '87, just a little more outboard
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dannygraves
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Post by dannygraves »

I ran the 250 kicker on my built '86 motor and seriously NO ONE could start it! it was hillarious, even MFDB couldn't do it, infact the only person besides me to ever start that bike was James Lewis and he was 12 at the time :lol: :wink:
'09 kx450f 4-Poke
Gen-4 trail bike --SOLD--
Gen-3 badass trail/mx bike --SOLD--
Gen-1 built dunes bike --SOLD--
'05 klx110 --SOLD--
'95 pw80
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Roostius_Maximus
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Post by Roostius_Maximus »

i'll admit i didnt do any machine work as far as deck height, the head is .015" tighter than a stock '00, the base gasket is cometic, but its tough. I'll take a video tonite

still got that kicker? $? gen1?
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