IMO OEM and aftermarket gasket kits are the same quality, but OEM is way more expensive.

personally I wouldnt use that liquid "form-a-gasket" stuff.

I have a 2007 crf 450 with about 100 hrs on it. Ive run honda hp4 10w40 full synthetic (the gold bottle) since it was new and change it every three rides. I check my valves twice a year and have never needed an adjustment nor have I ever had any metal shavings on my oil filter. This oil is awsome my buddy has on 07 crf 450 and runs standerd oil and he has pute two cranks in his bike with many valve adjustments. Not bad for three years of 20 min motos.

Your oil didn't affect the valve adjustement...it's your air filter...

Synthetic oil is better than Mineral, but the key stay changing it often as you can affort.

Run Amsoil in the engine and gonna try Honda HP trans oil for the transmission.



At 100 hours, you should at least replace your piston and rings soon !!!

Crumbshark said:

I would happily use aftermarket gaskets for the whole engine apart for the head gasket, i always use oem for that.

Maybe its just bad luck but the 2 bikes i've had with aftermarket head gaskets have blown them at low hours & once i've put oem in its never been a problem.

Well, after a year chasing the sun I am back and missing my cr so I have started back up on the rebuild. All my parts are in and was just working on cleaning the split case yesterday. Some questions:
1) do I need a bearing tool to remove some of those bearings? Is there any homefix solutions?

2) how do you get the oil seals out? I removed one of the crank oil seals and it was actually burnt on to the case. I used a knife to cut it but there is still a large amount of rubber residue remaining. Is there a simpler approach?

Thanks for your help guys!

I did the complete rebuild and bought most of the parts from servicehonda. saved quite a bit of money that way. I was told by many people that OEM parts are the way to go. I'm pretty sure Honda knows what they're doing. The OEM shop manual is way better than the clymer, but I ended up using both because some of the stuff was difficult to understand in the Honda manual. I paid for a clutch holding tool and I'm glad I did. Maybe it's not necessary, but it was cheap and worth it to me. Another tool that worked really good was the gear holder tool from motionpro. Just basically a piece of aluminum that jams between 2 gears so you can tighten/loosen without them turning.

Almost all of my bearings just fell out in the oven, and I installed almost all of them by hand after leaving them in the freezer overnight. The ones that hung up a little bit went in by tapping on them with a socket that was the same diameter as the outer race of the bearing.

The case split pretty easily for me. Be sure you don't over tighten the bolts holding the cases together. It's decieving in the manual at what they're supposed to be tightened too and I broke a few before I figured it out. In the front of the manual there should be a table with all the torque values listed for what size fastener you are tightening.

I had my top end done with SS valves and after the initial break-in they haven't budged. I'm nothing special on the bike, but I couldn't notice a difference in power. I did some reading some time ago, and brand new top ends are available for close to the same price as you would pay to rebuild yours. I'm pretty sure one of the moderators here sells them, I can't remember his name though...

Anyway, good luck on the rebuild, congrats on tackling it yourself, and use locktite!

FFTodd said:

Because the oem is for the pro tech. Need the common manual also. The Clymer manual is way more detailed.

winston64 said:

Its also straight up wrong in a couple places too.

Crumbshark said:

For seals, here is the easiest thing to do. If you have a sears (ish) store in the great north that sells tools, go over and look for a seal puller. It looks like a long screwdriver, but instead of the phillips or flathead, it has two opposing hooks that use leverage to pull the seals out without messing up the cases. Another thing that works is put a metal or wood screw in each side of the seal and pull with a pair of pliers.

So I am really having problms with these oil seals. They are baked onto the crankcase. Does anyone have any other suggestion for getting these out? I have tried to cut them out but this leaves a thick rubber residue all over and especially in the side groove....I have tried solvents to disolve the rubber and razors to tried to cut them out but it isnt working. Help! haha....if this cant be fixed I will have to invest in new L/R Crankcases. Where is the best/cheapest place to buy some crankcases?

i really hope i dont have the same problem, i am doing the same rebuild on my 2002.

have you tried spraying them down with WD-40 then trying to scrape them out? that is what i used to get baked on gaskets off.

Crumbshark said:

Buy a decent industrial heat gun. Not a damn hair dryer either, a heat gun. Get them hot and they should clean right up.

may want to try a dremell with brass wire wheel.  The brass wire wheel is softer than the steel or stainless steel wheel and is less likely to scuff the case.  be careful not to apply to much pressure

whats the preferred method to heating the cases to remove bearings? Are you also heating cases and freezing bearings to install? I can't use my oven so would an electric skillet work?

mattbmx, on 29 February 2012 - 07:41 PM, said:

Again, heat gun. Just heat the case surrounding the bearing and drive it out with a big socket or drift punch alternating sides.

Hey I'm somewhat new here and doing this rebuild. Im having a really hard time splitting the case. I've checked over and over and have all the bolts out and tried rubber mallet persuasion but not budging and dont want to spend money on case splitter when most people say i dont need it. any help would be great.

Case splitter is 60 bucks.Worth it, cause this is prolly not the last time you will split the cases.  But if that is just not happening, then try heat and patience......propane torch for short durations, or heat gun.  And gentle tapping.... with a soft hammer.  Also wd40 or pbblaster around where the boltss go through the cases, think that is where the pins are that rust up.  Could make your own splitter with flat stock steel and three bolts.....there are two bolt holes that are threaded with metric threads by the stator, and a long bolt to push against the end of the crank.  The catch is you need a cap for the end of the crank or you will ruin it.  A nut with a flat piece welded on it would work......If you can't fabricate these things....you had better buy the case splitter.

You shouldn't need a case splitter to part the cases on a crf. A hard plastic headed mallet is all you need. A rubber mallet wont get it. Put the long case bolts in the case saver holes, and tap the counter shaft  and the crank end with the mallet while holding the case about half an inch off your bench. Two strokes on the other hand..they need a case splitter.

I made an engine assembly stand out of a couple 2X4's. Tow longer ones on top parallel about 3" apart, then a pair to join them on the bottom at the ends. It holds the engine high enough that the shafts dont interfere with anything below. So the engine will sit flat on its side on the bench, counter, dinner table..washing machine...you get the idea.

Shawn_Mc, on 15 June 2012 - 05:16 PM, said:

Which bolt holes are the case saver holes?

Thanks for all the help and wisdom guys.
I'll try the practical stuff first but will end up fabing up case splitter eventually because my 2stroke is next.

You'll need a crank installer on a two stroke too.  Again think it's fifty or sixty bucks.....but you will wonder why you never bought it before....my case was rusted on my 07 crf450r and I used the splitter....glad I had it round...was worth it not to beat on it for hours.  Was prolly the extreme case...seems like thats all I ever get......you may be fine...it is the only four stroke case I have ever split.  Shawn splits one before breakfast...

Edited by shanecarr, 16 June 2012 - 11:19 AM.