mtneufer

Member
Jul 12, 2003
16
0
Im in the prosses of building a cr 500af.The chassis is a 2000 cr 250.I about have every thing to start putting it together.Til tonight,I droped the motor in and boy what a tight squeeze.Any ways the motor mounts dont line up.I am wondering if any one else has tried this,And what other problems will pop up and do you have a few sugestions.THanks,Mike
 

Yogurt

~SPONSOR~
Dec 25, 1999
218
0
Yea, your gonna have to have custom made head-mount stays. Also, I think someone on this sight maybe be able to provide you with the Pro Circuit pipe # you may need. Perhaps contact Service Honda, for they make CR500AF's them all time.
 

mtneufer

Member
Jul 12, 2003
16
0
Did any of you guys get your projects completed? I am in the process of building a cr 500 af right now,It is a 2000 cr 250 chassis and an 1989 cr 500 motor.Any suggestions or coments will be great.Also what pipe and silencer are you guys using.
 

KiwiBird

LIFETIME SPONSOR
Jan 30, 2000
2,386
0
You can use any pipe - just remove the rear mount. As for a muffle, that's a bit more work as the mounts are all different.
 

sunnyboy

Member
Feb 24, 2003
98
0
if you really want that thing to fly you need to bring the motor to 87-89 specs,honda de-tuned them after that so they would start easy,i have found that careful setup on the carb. makes them start in three kicks max.cold-one all day long.the extra power is great.have fun and keep us informed.
 

mtneufer

Member
Jul 12, 2003
16
0
So cal,I have a 89 motor,I'm going to have Eric port it just as soon as i get the bottom end mounted in the chassis.I'm also going to run a 39 mm kehin pwk off of a kx500.My most conncern is cutting and rewelding the motor mounts.Does any body out there know how far to drop the mounts,and any other problems I should think about be for cutting the mounts?
 

vic580

Member
May 9, 2002
77
0
I have a 1998 cr250 and at 260 lbs am also interested in doing the cr500af conversion.Is there an easy easy source for parts.
 

YZ-Red

Member
Apr 27, 2000
83
0
mtnuefer

With the gen 2 chassis you need to make a new front "y" frame piece were the exhaust bolts on as the 500 cylinder is taller.
Otherwise it is a fairly simple job. If you go to larrys page you will find all the info you need.

cheers
Red
 

mtneufer

Member
Jul 12, 2003
16
0
Red,it looks like to me I need to move the front motor mounts and the swing arm and bottom mount will line up once I've done that.That looks like the only hard part about getting this motor in.Do you know the part # for the pro circuit pipe and silencer.Any thing eles you can tell me will be help full.Thanks,Mike
 

mtneufer

Member
Jul 12, 2003
16
0
I went in today and cut off the front motor mounts,Now my swing arm bolt fits but the bottom motor mounts have to come out also.The need to come up about 1/2 inch.Now the front y wair the down tubes start needs modified also for the exhaust to clear.Once I have this dealt with it looks like I'll have some clearnce issues with the tank to deal with.
 

YZ-Red

Member
Apr 27, 2000
83
0
As i said the gen 2 chassis requires fairly major modification at the "y" section in front to clear the exhaust outlet, Service honda make up a new section and weld it in, however it is possible to cut out the factory section and modify to spec and re-weld in. You have to make sure you use a compatible alloy that is ok to weld, I used 6061 I think. If you do a search on alloy grades you will find the info.

Your bottom engine mount shouldnt need modifying, it should bolt straight in once you have clearance at the front, dont go cutting your bottom mounts off.

Use 500 swingarm pivot spacers with the 250 pivot bolt, you will need to machine a small amount of material of both spacers to fit.

You will have to make new top mounts/plates using 8mm alloy plate, I started with a cardboard version which i shaped and drilled, then flatten it out on the alloy plate, scribe a line and cut out, you can then bend the plate using the 250 plates as a guide.

Hope this helps.

Cheers
Red
 

mtneufer

Member
Jul 12, 2003
16
0
Red the front mounts are out,the motor is in and the swing arm bolt is in so every thing should line up on the swing arm bolt.I'm half a bolt hole off on the bottom motor mount.As far as the swing arm goes it fits perfect with out any spacers.I've heard that the 97-99 cr chassis you have to space the swing arm and the bottom mounts line up,but it seems this 2000 chassis is a little differnt.
 

nephron

Dr. Feel Good
LIFETIME SPONSOR
Jun 15, 2001
2,552
0
How much for tickets to watch you land your first triple on that thing? I guess I could bring the ambulance.

ie, 1) I hope you're an engineer, 2) I hope you know how to weld aluminum, and 3) I hope you don't start thinking about Ping's bike while riding. ;)
 

mtneufer

Member
Jul 12, 2003
16
0
Red I found a back issue of dirt rider mag that showed you how they did the 2nd and 3rd generation frame.They cut the hole front secound out from the y down below the front motor mounts.And in that case I can use my bottom motor mount since I will have the clearance I need.Then for front motor mounts they bored a hole right in the middle of the frame rails.I am not sure but it looks too be billet witch should be strong enough.I am having a machine shop that spealizes in alum fabrication do the work,I just want to make sure every thing fits the way it should once they weld.I only want to do this once.
 
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