CRF450 not starting after I took it appart (imagine that)

[Indy]

Howdy all,

CRF450R
2004


I just finished putting my bike together and it will fire but will not run. I pulled the engine apart to look at the transmission (changed out some parts) and just finished putting it all together. I re-checked the cam timing and it appears fine, I then triple checked it to confirm it is proper. I have fresh gas and a new plug.

Timing: Lined up the arrow on the cam holder to the gear flat mark; cam is in the up position pointing toward the rear of the bike. I lined this up after having the primary gear mark lined up with the index mark on the right crankcase cover. I had a indicator to prove that the piston is at TDC.....As per my manual.


Is it possible that the ignition timing is out, sparking after TDC on the compression stroke?

Any other ideas? Let me know if you have any ideas or if you require more information.

Indy.

 

[_JOE_]

Did you look under the ignition side cover to ensure everything is lined up there?

 

[Indy]

I pulled that side cover, I have not adjusted anything other than taking off the flywheel when I disassembled it. It is lined up with a woodruff key, so it cannot be miss-aligned?

 

[IndyMX]

You need to pull the plug out of the side of the ignition cover, be careful when you put it back in, it will snap in two if you over torque it. (Guess how I know this)

Line up the timing mark on the flywheel with the mark on the cover, plus have the mark on the crank side lined up..

Then look at the mark on the cam. This will tell you if you are a tooth or so off.

1 tooth off will make it a real ******* to get it running. (Again, wonder how I found out)

If everything lines up, you have fuel, clean air filter, good plug and all that, it should start and run.

 

[nikki]

You need to pull the plug out of the side of the ignition cover, be careful when you put it back in, it will snap in two if you over torque it. (Guess how I know this)

Don't feel bad, you're not alone. Red's snapped one of those too.


Another thing to check is when the bike is at TDC, are you checking all of the valve clearances again? Once on a YZ 250F rebuild we had a shim that wasn't fully seated in its groove that threw us for a loop for a while, until we pulled out the feeler guages and noticed there was no clearance on that valve!

 

[Indy]

So.....I checked the valve clearance, they are within spec.
I have been following the manual but it seems to be missing some pages. I ripped all the other languages off of the back leaving the English section. :bang: (Really regretting that)

The mark on the flywheel (electrical side) and the mark on the primary drive gear (clutch side) will not line up at the same time on their covers marks at TDC. They are out a few degrees.

Did I make mistake at assembly?

There are two marks on the flywheel, they are close together <1/8" apart which one is supposed to align with the cover?

Is there an on-line manual?


Indy.

Thanks for the help.

 

[Ol'89r]

The mark on the flywheel (electrical side) and the mark on the primary drive gear (clutch side) will not line up at the same time on their covers marks at TDC. They are out a few degrees.
.

When you align the mark on the primary drive gear you have to be sure to be looking at the mark with your eyes parallel to center of the gear. If your eye level is above or below the gear and pointer the alignment will appear off a little. It is very easy to be off one tooth.

 

[Indy]

Finally got around to fixing this bike - found the flywheel was not torqued proper leaving the flywheel out of alignment. Just enough I could not tell looking at it straight on. Torqued it and there was slight movement. The Bike fired right up.

Next issue:

The kick starter housing is cracked so is the case behind it. (It was a really rough trip last time I had it out, cracked the other side case as well)

What should be the amount of time required to split the cases to replace the cases? Looking for an estimate of time so I can make a decision on how much of the work I do and how much the local shop will do. I will probably tear into it as much as I can then take it in as I assume pullers and other tools I don't have are required to do the swap out?

Indy.

 

[Ol'89r]

You might want to check with some of your local shops to see if there is a good tig-welder in your area that is experienced in repairing cases. Might be able to be repaired without taking it apart.

 

[IndyMX]

You might want to check with some of your local shops to see if there is a good tig-welder in your area that is experienced in repairing cases. Might be able to be repaired without taking it apart.

I second that...

Cases are kind of expensive.. The repair shouldn't be that bad. And since the cracks are most likely just hairline cracks, they should be fairly simple to repair.

And again, be very careful during assembly so that you have everything seated and aligned properly or you too will become very familiar with that horrible "tink" sound.

 

[Indy]

That did occur to me but I was scared about warping and getting the proper pre and post heat treatment on the cases. Also worried about getting heat into places like seals and such.

What would the weld procedure be for thin aluminum?

The cracks are hairline.



Indy.

 

[IndyMX]

If it was me, I'd tear it down to have it welded, then replace the seals and gaskets..

 

[Indy]

I have two cases to fix so...
I think I'm going to order a new case on the inside as I don't want to have to split the cases again if the weld doesn't work out. I'm going to try to weld the middle one and see how it turns out. I have a welder buddy who should know how to weld this properly. If it doesn't work it is no big deal to rip that middle piece out and replace it. (Sorry thinkin' out loud)


Does anyone know the grade of Aluminum that the cases are made from?


Indy.

 

[Ol'89r]

Make sure your welder buddy is experienced with welding castings. The cast grade of aluminum used on the CRF engine is a fairly clean casting and is very easy to weld. Some castings are very dirty and weld like trying to weld a sparkler. If your buddy has any questions, have him PM me.

 

[Indy]

Bought new cases for both the inner and outer housings. Don't want any issue with a broken case due to improper welding or heat treating to cause a breakdown while on a ride. I'm sure that it can be done and done well just want piece of mind. Thanks for everyones help.

Indy.