My 89 engine needs rebuilt.....

[scooter5002]

I didn't get to this thread yet Clyde, It was actually .055"

Having come from ancestors of Scotland and England I was waiting for someone with an Inuit background to chime in

Righteous bloodlines, dude! I can see you and I are going to get along well. ROBERT THE BRUCE LIVES FOREVER!!!!!!

[Doppler]

Cant you guys bitch away at each other in a PM?

[Roostius_Maximus]

heck one branch of the family came to Canada from England deported by the king for having physically kicked the prince's ass. Story goes that the king agreed it needed to happen

[AlisoBob]

So what's the problem with the HOOKERS, Bob?

Their male....

[100hp honda]

to this day i never seen anyone do a crf250 conversion and put the engine straight up and down except bobski . fine piece of engineering ya got there

[gregrobo]

wow another epic thread

[AlisoBob]

.... fine piece of engineering ya got there

Yup... sure is.

1. Exhaust fits perfect

2. Chain slider isnt wearing all funky

3. Countershaft sprocket is in the same place as the 4 stroke

4. Clutch cover script is level, like it was in the steely.

WTF have you ever built Clyde??? Oh yea... nothin.

Your so stupid, it hurts...

[Doppler]

Please go jack some other thread. This isn't helping me with the things I have asked.

[AlisoBob]

You got your answer.... run it.

[Doppler]

Yes I did get THAT answer about the crank....
That wasn't the only thing I asked.

I really need to know what machine work needs to be done for the 91mm piston. Obviously bore the cylinder.

What about the head? Some say it needs to match the bore and others say it doesn't. Can't get a clear answer on that.

What needs to be done on the exhaust bridge? I see some people relieve it some?

What about port timing with the bigger bore? Does it really move it?

How about porting?

Who should I have do my machine work? Someone who doesn't break the bank would be nice. There are people local, but they know nothing specific about CR5s let alone 91mm info.

I only ask for info. on the 91mm size because I've read it takes a little more to make it work.
But again.....no clear answers from things I've read.

[AlisoBob]

I really need to know what machine work needs to be done for the 91mm piston. Obviously bore the cylinder.

Do you really need to go to 91MM?

What about the head? Some say it needs to match the bore and others say it doesn't. Can't get a clear answer on that.

Of course it does, if you want it done correctly

What needs to be done on the exhaust bridge? I see some people relieve it some?

It ALWAYS needs to be releived

What about port timing with the bigger bore? Does it really move it?
No

How about porting?
I've met 4 people who ride a CR500 WFO. I doubt your #5.

Who should I have do my machine work? Someone who doesn't break the bank would be nice. There are people local, but they know nothing specific about CR5s let alone 91mm info.

Theres members here....hit them up.

I only ask for info. on the 91mm size because I've read it takes a little more to make it work.
Nope

[Roostius_Maximus]

Yes I did get THAT answer about the crank....
That wasn't the only thing I asked.

I really need to know what machine work needs to be done for the 91mm piston. Obviously bore the cylinder.

What about the head? Some say it needs to match the bore and others say it doesn't. Can't get a clear answer on that.

What needs to be done on the exhaust bridge? I see some people relieve it some?

What about port timing with the bigger bore? Does it really move it?

How about porting?

Who should I have do my machine work? Someone who doesn't break the bank would be nice. There are people local, but they know nothing specific about CR5s let alone 91mm info.

I only ask for info. on the 91mm size because I've read it takes a little more to make it work.
But again.....no clear answers from things I've read.

Nothing special to go 91mm, same stones, ball hone, boring bar whatever

The bridge needs the same relief the honda manual instructs, nothing special.

if its a wiseco piston, drill holes at the bridge like its instructions show.

port timing is not going to change, the chamfer of the port edge is probably 4 times what difference the bigger bore would do.

match the head bore so its not making a shelf, also use the wiseco/cometic gasket kit so you have a larger bore gasket.

about the porting, you can do a little work to it and screw it up, or tons of work to it and screw it up .
You need to set a budget for the portwork and i'm certain you'll get advice on who will work on it or what can be told to help you with it.

[Tharrell]

I'm with Bob on the porting.
Unless you're running dunes, it's probably a waste and will most likely take away from the fun.
A stock CR500 is more than plenty for most people.
My '92 was built before I got it and it's a handful for me.
I'm not used to having the gas cap in the crack of my ass to keep the front end down.
Maybe if I had footpegs built onto the front axle it might work.

[AlisoBob]

I'm not used to having the gas cap in the crack of my ass to keep the front end down.

I'm about 270 right now, geared up.

It amazes me at my size, how easy it is to get the front end up.

I think we've all been sitting on the cap from time to time....

[Doppler]

Oh i agree its plenty fast as is (or was) especially in low to midrange on trails. The only thing it lacked was on top on high speed desert runs. Part because the close ratio 89 gears and part due to the 14/51 gearing i had. Same as stock i believe. I am going to try 15/51 after the rebuild and see how that goes. That may fix any issues i had.....hopefully. 1st gear was pretty useless most of the time anyway

[freeride588]

Oh i agree its plenty fast as is (or was) especially in low to midrange on trails. The only thing it lacked was on top on high speed desert runs. Part because the close ratio 89 gears and part due to the 14/51 gearing i had. Same as stock i believe. I am going to try 15/51 after the rebuild and see how that goes. That may fix any issues i had.....hopefully. 1st gear was pretty useless most of the time anyway

I would run a 14 tooth front if you have an oring chain as it can touch the cases. Run 14-48 and you should be good that is close to 15-51

[Tharrell]

I agree, first gear is kinda useless if you have the close ratio tranny.
If you port it, it will become the scary gear.
You'll be looking like this through your goggles----

[jbsleddin]

I agree, first gear is kinda useless if you have the close ratio tranny.
If you port it, it will become the scary gear.
You'll be looking like this through your goggles----

Or performing new tricks such as "climbing the chain"

[AlisoBob]

[Doppler]

I'll be running a non O-ring chain. Clearance should be okay with that and the 15th right?

[freeride588]

I'll be running a non O-ring chain. Clearance should be okay with that and the 15th right?

Should be no problem just check it after your first ride.

[Tharrell]

I agree, first gear is kinda useless if you have the close ratio tranny.
If you port it, it will become the scary gear.
You'll be looking like this through your goggles----

Or performing new tricks such as "climbing the chain"

Damn.
Didn't kiss me or buy me dinner.

[jbsleddin]

I agree, first gear is kinda useless if you have the close ratio tranny.
If you port it, it will become the scary gear.
You'll be looking like this through your goggles----

Or performing new tricks such as "climbing the chain"

Damn.
Didn't kiss me or buy me dinner.

If I remember correctly (and I'm damn sure I do) YOU were the one chasing me for my "FATTY".......

[freeride588]

Or performing new tricks such as "climbing the chain"

Damn.
Didn't kiss me or buy me dinner.

If I remember correctly (and I'm damn sure I do) YOU were the one chasing me for my "FATTY".......

I seem to remember a little FATTY chasing

[Doppler]

Here's my crank. First pic looks like the rod is grooved with the washer sucking into it, but it's just the angle of the picture.