Some stupid rebuild questions

[Revver]

OK, so I decided to do the top end on my 2001 cr250, and of course I have some stupid questions for the sharp minds on DRN.

1.) Everything was going good until I tried to pull the jug off. For some reason, I cannot seem to pull this thing from the cases. I can jiggle it a little side to side, so i know it is loose, but it won't come upwards. I tried giving it a tap with a mallet but no joy. :bang: I thought about slipping a flat head in between there and prying upwards but that makes me a little leery. What do you guys recommend I try? I've got a friend coming over to help me tommorow so maybe our combined elbow grease can fix that little bast**d.
2.) I removed the cover form the powervalve and it is GUNKED UP!!. What is the best way to clean it. I've heard alot of people use oven cleaner, I've thought about trying carb cleaner to blast it clean but i don't know. Will any of these solvents have an ill effect on the bearings, or should I just blast those clean as well. Upon reassembly of the powervalve, should I lubricate all the parts or just a few drops on the bearings?
3.) I do not have any crows foot sockets for my torque wrench. Whats the best way to tighten down the cylinder nuts without a torque wrench?
4.) Lastly, is it imperitive to use a petroleum based oil for break in, or could I get by with mobil mx2t. I know alot of purists say use the dino, but is this truly neccesary?
Thanks .

 

[nickyd]

PUT THE FLATHEAD SCREWDRIVER DOWN!! AHHHHHHHHHH...first off, sounds like your first adventure - while the many intelligent minds here will be able to tell you some good stuff and get you through the rebuild, may I suggest spending $20 on a clymer manual - next to the right tools, there is nothing more valuable in my opinion.

as for the cylinder - are you sure you're all clear and unbolted (p-valve actuator disconnected where applicable, all the bolts, etc?)

the powervalve is surely gunked - I use a stiff brush and elbow grease as well as some parts solvent - the oven cleaner will work but can be caustic to the aluminum so use wisely.

you don't need the crows foot - motion pro makes a torque wrench adapter - I use common sense and cross tighten with a box wrench - if you have the adapter, great...if not those 4 base bolts are not put on there ultra tight - just reference how hard they were to get off - probably not very...for the record, proper torque is wise.

as for break in, i won't go there...there are too many opinions..I use the same premix to lube when assembling that I do when riding....never noticed any ill effects.

 

[mtk]

Skip the Clymer manual. They blow, as do Haynes and anything else not written by the folks who manufactured it. They're better than nothing, but not worth it if you can get the real deal.

Go to e-Bay and find a genuine Honda Service Manual. Buy it. Skip anything that doesn't say "Honda" on it. You'll be glad you did.

I used a torque wrench on three of the four base nuts. The one I couldn't get to, I used a box end and did it by feel. Not ideal, no, but it works well enough.

As for break-in/reassembly, I took a Q-tip and applied oil to the cylinder wall. Not much, just enough to lightly coat it. Same with the piston skirt. Using my finger, I put a wee bit on the wrist pin and the pin bearing and rings. It came out with that light film on it so I put it back together with the same. Some folks put them together dry but that just doesn't sit well with me.

 

[nickyd]

i'll agree that a genuine factory manual is better than a clymer...but be realistic...clymers are MUCH easier to understand - dude seems like he's on his first build....as stated factory is ideal but may be a little confusing at first...and in my opinon, F paying the price they command just because the factory can charge it.

 

[Revver]

I do have the factory manual from honda. As you can imagine, it is less than vague on some things. It gives no advice on how to seperate the head from the cases. I read in a recent issue or drm that upward taps with a mallet can free the cylinder but I wasn't that lucky. This is not the first engine rebuild I have done. I helped my friend rebuild his yzf600r motor and we didn't have a hard time removing the cylinders from the cases. That's why I don't understand why one cylinder can be such a pain in the a**. I've triple checked the manual on the procedure and I have follwed everything to the T. I'll see if an extra pair of hands will help tommorow. Thanks for the replies guys.

 

[keithb7]

I just did the top end on my 93 CR250 2 weeks ago. The cylinder was a little stubborn to get off, but not as bad as you describe. I found that moving the piston lower in the cylinder, using the kick starter slowly, eased up on some of the stress in sliding the jug off. Keep tapping all around in a slightly upward motion with a rubber mallet. It will come off. Everything was running good till you decided to redo the top end? Is there a possibility there is a ring caught on a port. Or maybe a hot seizure with the piston or rings stuck to the cylinder walls? I agree with the folks supporting the OEM Honda manual, Clymer & Haynes suck compared to the Honda one. I have given up completely on non OEM manuals. I got mine on E B A Y for $12. A great deal.

 

[mtk]

i'll agree that a genuine factory manual is better than a clymer...but be realistic...clymers are MUCH easier to understand...

...and typically riddled with errors. I'll take slightly confusing and correct over easy to read and wrong any time.

In addition, bad information at a cheap price is no bargain.

 

[nickyd]

...and typically riddled with errors. I'll take slightly confusing and correct over easy to read and wrong any time.

In addition, bad information at a cheap price is no bargain.

awwwwww c'mon that's half the fun (just kidding).

 

[Joe_148]

when I did mine I just useed the mallet and hit it upwards at a 45 degree angle, then after every few hits just grab both sides of the cylinder and rock it back and forth on the dowels she'll come eventually, if not just hit it upwards harder..

 

[CRguyStan]

I would say one of the cylinder alignment pins in corroded to the stud in the case and the cylinder. Keep working your way around the cylinder with the rubber mallet and it will eventually break free. The four bolts are the only things holding the cyclinder on the 01 CR250.
When you reassemble, make sure to get the power valve actuator arm in time with the case, or you will split to lower fork and need a replacement.
Stan