500 AF With 1986 CR 500 Motor

[CR500PHIL]

Is it possible to use a later model CR 500 pipe and kickstarter on a 1986 motor? I am thinking of using an 1986 motor in an Gen 1 AF project but want the low boy pipe and new style kickstarter. Anyone else do an 86 AF project? Is the 1986 a very powerful motor compared to later CR 500s?

[Slow old Fart]

You can use that motor and you can update it close to like the new specs, the kicker and pipe will work on it but you should spend a little more and do a gen 3 or 4.

Handling and ride wise a GEN 1 is disliked by many. Alot of folks would take a steelie over a gen 1 depending on what you are doing.

[CR500PHIL]

Are the 1986 CR 500 motors very powerful? I am wondering if I would notice a bigg difference between the tricked out 03 YZ 250 I have and the 86 500 AF once it is built. I choose Gen 1 for the ease and cost but I consider other Gens.

[Slow old Fart]

If you want a conversion to keep for many a year and really enjoy it you need to do a newer one IMO.

The 86 CR5 will make way more torque than your 250. They are a good motor but the electronics are a one year wonder. I actually like the 90 and newer bottom end with a old style cylinder. ALL ENGINES CAN BE UPDATED or changed to meet needs.

[CR500PHIL]

So will the 92 and up cylinder fit the 1986 bottom end? Will the 92 and up head fit the stock 86 cylinder?

Thanks for all the info.

[robertg]

This will help you.

http://cr500riders.com/cgi/yabb/YaBB.pl?num=1192743820

[Nodge]

Ignore the old fart.
Gen 1's are great.

Build it! I have an 85 motor in my gen 1.

[CR500PHIL]

Has anyone ever used a 92 or newer cylinder on a 1986 bottom end?

[dannygraves]

go look up my gen-1 build! I used an '86 motor.
the '86 motors haul ballz! in my build I also show how I routed the hose around the pipe and the new style kickers do bolt on. the rear beushings are smaller, but you can take the bushings out of your gen-1 stock motor, drill the cases and tap those in.
I was riding my gen-1 yesterday and I actually like the way it rides in the dunes better than my gen-4. Infact, the wife says 1 of the 3 bikes has to go, so I am thinking about selling the gen-4 and keeping the gen-3 and 1.

I do think the gen-3 is the best conversion to do. it comes out super clean with only a few hours of work and has the latest goodies on it. I got my gen-3 as a busted up complete bike for $700 and sold off spare parts for $450, so they can be had for cheep.

slow old fart doesn't know what he is talking about, he usues radiator hoses and duct tape to mod an air box on a dunes bike!

[dannygraves]

Has anyone ever used a 92 or newer cylinder on a 1986 bottom end?

the cases need to be machined to accomidate the larger sleeve. run the '86 jug, isn't one of the best power building setups, the ports are huge.

[dannygraves]

BTW, '89+ is the fitment and '90+ is the porting. If there were any changes after '90 they were minumal at best.
the '89 jug has porting like the older bikes (big wide-ass intake port), but has the water inlet and thick sleeve liek the '90+

[dannygraves]

So will the 92 and up cylinder fit the 1986 bottom end? Will the 92 and up head fit the stock 86 cylinder?

Thanks for all the info.

the heads have the same basic casting from '85+, but the '85-'88 used a thicker head gasket and '85 and '86 had higher compression. a good mod for torque would be to take a '85 or '86 head and run it with a '89+ gasket. thats the same as shaving off .040"

[Slow old Fart]

Has anyone ever used a 92 or newer cylinder on a 1986 bottom end?

the cases need to be machined to accomidate the larger sleeve. run the '86 jug, isn't one of the best power building setups, the ports are huge.

This is the clown right here! The 85 thru 88 run the same cylinder. The earlier version require less porting over a 89 and later becuase they have better mating surfaces closer to spec. In 89 they went to a much thicker liner because people were running the pistons to loose on the 88- 85 and the bottom part of the skirt liner would brake. Port timing is indentical on 85 thru 2001 cylinders. All things considered you will notice better throttle responce and quicker pull on a old style cylinder because they scavenge better across the lower RPM range stock.

The new style cylinders require much more port work to get them to flow as well as a old style with mild porting. Much of the flat spot on the bottom end of new style Cr 500 can be alieviated by running a old style cylinder.

The 86 motor makes more torque than a 87 thru 2001 but makes less Peak HP! The 5mm shoreter rod trades HP for out of the hole torque. I like the 87 and newer 5mm longer rod because the power is broader and does not require shifting as much because they produce more HP in upper rev range.

[dannygraves]

that was supposed to say "it's" not "isnt". that was a typo.
'85 and '86 share the exact same jug and '87 and '88 share the same, but the 2 are not identical. they use a different sleeve since the port dimensions changed, but the port timing, as you stated, has always remained the same.
and '86 jug on a long rod motor is wicked, especially running 190*ex 130*in w/ additional transfers! oh, wait, thats what I was running this weekend.

btw who the fuck are you calling a clown?!

[CR500PHIL]

the rear beushings are smaller, but you can take the bushings out of your gen-1 stock motor, drill the cases and tap those in.

This scares me a little - do you have to take the bottom end apart to do this? I assume you would do this with a drill press? Did you do this yourself or have this done at a machine shop? Excuse my ignorance - I want to do my hoemwork before beginning so I know what I will be up against.

[dannygraves]

the cases can stay together. I used and hammer and chisel to tap the old ones out. used a 18v hand held drill and 13/16" drill bit to drill the cases, then tapped the new bushings in. took 10 minutes, no biggie.

[Slow old Fart]

that was supposed to say "it's" not "isnt". that was a typo.
'85 and '86 share the exact same jug and '87 and '88 share the same, but the 2 are not identical. they use a different sleeve since the port dimensions changed, but the port timing, as you stated, has always remained the same.
and '86 jug on a long rod motor is wicked, especially running 190*ex 130*in w/ additional transfers! oh, wait, thats what I was running this weekend.

btw who the fuck are you calling a clown?!

The porting is the same 85-88 SAME CYLINDER.

The only thing that is fifferent on a 89 forward for the most part Honda opened boost ports shortned the intake and made a smaller shorter reed cage to shift power up and try and eliminate some of the mid hit on the 85-88.

That in conjuction with a 5mm rod and heavier crank tamed the beast a good bit. The pipe was also designed to spread power up to take torque out of hit.

[CR500PHIL]

the cases can stay together. I used and hammer and chisel to tap the old ones out. used a 18v hand held drill and 13/16" drill bit to drill the cases, then tapped the new bushings in. took 10 minutes, no biggie.

Oh ok - sounded like more than that. I may get an 86 motor to do the project with - may have a chance for a good deal on one. Thanks again.

[dannygraves]

that was supposed to say "it's" not "isnt". that was a typo.
'85 and '86 share the exact same jug and '87 and '88 share the same, but the 2 are not identical. they use a different sleeve since the port dimensions changed, but the port timing, as you stated, has always remained the same.
and '86 jug on a long rod motor is wicked, especially running 190*ex 130*in w/ additional transfers! oh, wait, thats what I was running this weekend.

btw who the fuck are you calling a clown?!

The porting is the same 85-88 SAME CYLINDER.

The only thing that is fifferent on a 89 forward for the most part Honda opened boost ports shortned the intake and made a smaller shorter reed cage to shift power up and try and eliminate some of the mid hit on the 85-88.

That in conjuction with a 5mm rod and heavier crank tamed the beast a good bit. The pipe was also designed to spread power up to take torque out of hit.

hhhmmm, then maybe you need to talk to those guys at LA Sleeve... they obviously have no idea what they are talking about...
those morons actually have different part numbers for '85-'86 sleeves and '87-'88...
Maybe I should call them and tell them SOF is the ultimate authority on the topic and they should drop one of those SKUs from their inventory

[Balaclava]

ok ok i would love to start throwing punches but i'm just as ignorant as phil...I actually love the way a nicely powdercoated black engine looks and since the 86 has that reputation of being such a powerhouse i've recently been looking at a 86 bike to use the engine for my 02 450 conversion. My 97 is going to be used in my new Gen 3...now what i'm wondering is if the 86 would mount up the same as my 97 in an already converted frame? Headstay wise, motor mount wise? if it does then i think i'm going OLDSCHOOL...

[dannygraves]

the headstay will be off by 5mm, but that is so small that in some cases the gap in the bolt hosle will allow that much adjustment, and the rear bushings, the rest is the same.

[Balaclava]

Dannygraves, you ah da MAN!! What is stock compression in 86' opposed to say 94 and newer? this guy says he has 'high' compression in his 86...

[dannygraves]

the '85 is 7.4:1, '86 is 7.0:1 and '87+ is 6.8:1

the guys could mean the head was modified, could mean a newer head gasket was used (simulates shaving .040" off)
or he could just mean its hard to kick and shows signs of good compression and thus a healthy motor.

[Balaclava]

thanks homie...

[Slow old Fart]

that was supposed to say "it's" not "isnt". that was a typo.
'85 and '86 share the exact same jug and '87 and '88 share the same, but the 2 are not identical. they use a different sleeve since the port dimensions changed, but the port timing, as you stated, has always remained the same.
and '86 jug on a long rod motor is wicked, especially running 190*ex 130*in w/ additional transfers! oh, wait, thats what I was running this weekend.

btw who the fuck are you calling a clown?!

The porting is the same 85-88 SAME CYLINDER.

The only thing that is fifferent on a 89 forward for the most part Honda opened boost ports shortned the intake and made a smaller shorter reed cage to shift power up and try and eliminate some of the mid hit on the 85-88.

That in conjuction with a 5mm rod and heavier crank tamed the beast a good bit. The pipe was also designed to spread power up to take torque out of hit.

hhhmmm, then maybe you need to talk to those guys at LA Sleeve... they obviously have no idea what they are talking about...
those morons actually have different part numbers for '85-'86 sleeves and '87-'88...
Maybe I should call them and tell them SOF is the ultimate authority on the topic and they should drop one of those SKUs from their inventory

I don't care what LA sleeve has for numbers. I have probably 15 cylinders in the garage and have looked at all the years over and mic'ed them. There may be slight difference because in 87 they went with a longer rod and LA sleeve probably made the sleeve longer but the Honda cylinders are the same. That is why honda redesigned it in 89 the 88 n 87 did not have enough support at the bottom and ther was a 5mm gap and the sleeve would crack, timing and port demensions are the same.

Young man you are becoming tiresome!