CR125 Build up

[Micahdogg]

So this is the bike, which was recently acquired for my friend's first ride.  It needs some love, so I'll just keep a log of what we are doing, spending.  Maybe someone will find it useful, entertaining, or get a good laugh at our expense.


Here is your average $850, "probably not stolen, but we'll take a bill of sale anyway," 1999 CR125.

The good = the plastic matches and isn't broken.  It starts.  Clutch feels adequate.  It goes through all the gears. Forks/shock do not appear to be leaking.

The bad = A group of 16-year-old kids took turns wrenching on it, and learning to ride on it.  That, in addition to:

- The tires (Scorpion brand) are completely shot.  Knobs are torn off.
- Front innertube is shot
- Shock linkage bearings are completely missing
- Gas tank has a couple hairline fractures around the neck (this may not be a big deal)
- The pipe looks like it was next in line after the fax machine in "Office Space."
- The silencer isn't silencing anything
- Carb vent lines are munsoned up and completely blocked off
- Grips are mismatched, torn and have "wire-o-death" protruding from them.
- Sprockets are about 30%, chain appears to have been from different machine, so it binds/catches badly
- This 1999 CR125 is actually 1998 CR125 (per the sticker on the neck)
- Coolant was about 25% full.
- Plug was brand new and not even fully seated.....hmmm.
- The front brake pads were stacked on one side of the rotor, and the caliper housing was pressed against the other side of the rotor.  Did a little damage to the caliper housing.

[MyckMcClung]

check all the wheel beariings
order the parts you listed it needing
get a large assortment of replacement fasteners, as Im sure 80% of the ones left on it are either rounded or galled with visegrip teeth.
Get a big tub of marine grade wheel bearing grease, lithium grease, 5 gallons of contact cleaner.
take it completely apart
and start from the ground up

[Micahdogg]

First thing we did was to check the vitals.  This was supposedly "rebuilt" with a new OEM top end just 2 months ago.  I don't doubt that it was rebuilt, but I bet it was closer to a year ago.  I was expecting about 145psi and it cranked out a solid 150psi on a cold cylinder.  I think this is good enough to leave alone for now.

Next, we dumped the coolant and while it was clean, we were amazed to find about a coffee cup's worth of coolant in the entire system.    We completely filled the radiator and it did not leak out anywhere.  Not sure what happened to the coolant.  Maybe it was just neglect.

Dumped the oil. Was really glad to see some oil in there and it showed no contamination from coolant.  Refilled with plain ole Penzoil 10w30.  

Pulled the air filter.  It is old, but acceptably clean and has no holes.  We will clean this and reinstall it.

Pulled the carb.  It too was acceptably clean, but the floats were VERY VERY out of whack.  Bent the tang and set them level to the mating surface again.  Gave everything a good spray of brake cleaner.  Took note of the jet sizes/clip position for later.  Was happy to be able to reuse all OEM carb lines (after a good cleaning) and all OEM clip retainers.

Removed shoddy grips and installed a set of new SDG grips that the company recently sent me for free and I had absolutely no use for.  Good timing.  

Went through my pile of OEM jap bolts and replaced the ones that were missing.  

Removed slug of carbonized gunk from silencer, opened up all the perforations with judicious use of a trim nail and vice grips, used FMF silencer packing and buttoned it all up.

Money spent so far - nada.  All items were laying around garage and donated to the cause.

[Micahdogg]

take it completely apart
and start from the ground up

If this were my bike, that is exactly what I would do.  In fact, if this were MY bike, I would dump another $2000 into it and make it a minty "original looking" 98 CR125.  Actually, if it were my money, I would have saved up to $1500 and bought a nicer bike.  BUT, this is the path that was chosen, mostly for budgetary reasons and my friend wanting to get something asap.  Thus, we are on a severe budget.

The goal is to have a mechanically sound, well running, fully operational bike that looks presentable for as little money as possible.  Unfortunately, due to the seat cover not actually having any punctures or rips, it is going to stay for now.  I think you could say that it looks presentable, even though I hate it.

That aside, if anyone has just a black gripper cover that they would like to donate to the cause, I would happily install it.  Unfortuantely, the only gripper cover that I have is black with a HUGE yellow swatch right through the middle.  I'm not sure that it would be an upgrade in the "looks presentable" department.

[TMKIWI]

Get rid of the "Monster" graphic.
Everyone with a snotty nose has them.
Be original.

[Micahdogg]

That picture is how the bike was purchased (flat front tire and all).  The graphics have already been jettisoned.

[TxTechRedRider]

very cool project
good luck with it

[Spooney]

I would really suggest replacing the tank. I had hairline cracks in mine(before the rebuild) and it ended up failing deep in the woods and by the time I got back to my truck I was soaked in fuel from my waist to knee, and my bike was covered in fuel aswell. This can be very dangerous.
I scored one from clarke directly really cheap from their scratch and dent sales. If you want really really cheap you could always get a used one off ebay, I wouldnt trust the plastic weld technique though.

Good luck, and it looks like a fun project!

[Micahdogg]

Thanks.  Yeah, the cracks don't give me warm fuzzies, but the condition of some of the used tanks out there look like just as much of a gamble.  The game plan is to at least try it and see how it goes first.

Still waiting for parts, but there is a slight update.

We polished up the Pro Circuit shorty silencer and assembled it with fresh packing.  As it got bolted into place, I suggested we give the bike a start and see how it sounds.  Keep in mind, I've had the carb and filter off of this so I wasn't quite sure what to expect.

It started in about 5 kicks, revved up good, sounded MUCH MUCH better.  As I was fiddling with the choke/idle adjuster and giving it some short bursts of throttle, I noticed some fluid spraying out of the bike.  Like - SPRAYING OUT!  It was dusk and I couldn't see well so I immediately let off and assumed it was gasoline from the carb (since I tweaked the floats so hard).

Turns out it was coolant spraying out of the overflow?!?!  It emptied at least 1/3rd of the coolant very quickly.  SO I pulled the radiator cap and inspected it.  It looked fine.  I started it with no cap and as I gassed it, you could see the bubbles coming out of the radiator and the coolant rising up to the neck very quickly.  I cupped my hands around the neck and stuck my nose in there.  It smelt like exhaust.  That is definitely a problem.

We already had a top end gasket kit coming because we were going to inspect the top end, so I hope it's just a blown headgasket.  Considering the goobers who were working on this bike, I wouldn't be surprised if they tried to reuse the head gasket.  BTW - I did check the head nuts and they were all pretty tight.

More fun to come.  But the bike sounded really good and felt pretty crisp considering it was probably drinking some coolant.  Can't imagine how much better it'll be with that issue fixed.

Oh, and the kill switch does not work.  Need to investigate that out.

[eprovenzano]

For $850, you really can't go wrong.  all used bikes need TLC.  I look at tires, chains, and sprockets as wear items, that I would replace soon after the purchase.  You seem to have the things under control and are working out the bugs the proper way.  A little maintenance goes a long way.  Think of it this way, when your done, you will know it will be reliable, and most of all a fun bike to ride... 

Good luck and keep us informed. 

[MyckMcClung]

man leaky gaskets suck, tear that sucker down when the new ones come in and check the head carefully, it could be warped, or have a gouge causing the leak.
 Clarke has good, inexpensive tanks, and they have  oversized as well,

[Micahdogg]

When I recently restored my ATC250R, I tried to save some money with a K&S gasket set.  That head gasket leaked immediately.  I torqued it propery and with new nuts/washers.  I was amazed to find coolant dripping out of the front of the cylinder upon the first ride.  SO it is in the back of my mind that a bunch of kids would find a cheap K&S gasket set attractive....and maybe that also is the culprit.

Gonna have to wait.  Damn Rocky Mountain ships SLOW!!!

[MyckMcClung]

I had great luck with K&S gaskets and fork seals on my old YZ, maybe the don't like ATV's

[Micahdogg]

Got some brand new Maxxis IT tires yesterday (best bang for the buck).  We reused the rear tube and installed a brand new "cheapo" front innertube that was given to us with the bike.  Also, due to the extreme budget, we busted out the ole tire spoons rather than pay $20/wheel at the local shop.  That sounded like a great idea, but I'm a little rustier with the spoons than i thought so they gave up a good fight.  But we triumphed greatly with no pinched tubes and two new tires that hold air.

Tires were $100 on the dot shipped.  So we are at $950 total.  

It's already looking better.  The rear rim looked like cement (if you can see in the pic in the first post) so I did a quick and dirty polish job to get it to match the front.

[Micahdogg]

Onward and upward.....er sideward. 

The shock linkage was pretty well blown out as evidenced by this picture:



Notice the right-most bolt has NO bearings at all.  Yeah, not only are the needles gone, but the outer races are gone.  It's like someone started working on the linkage, then decided "F*** this, just sell the bike," so they plopped the bolt back in there.  We didn't notice this immediately, but as soon as I picked up the bike to put it on the stand I noticed about 1 inch of "clunk clunk" play in the suspension.  It was this bolt, along with the other loose linkage bearings causing all the play.

Here is the after shot.  I used a "Factory Spec" brand linkage kit because the owner didn't want to spend $75 on a Pivot Works kit in the event the linkage bores were smoked.  As luck would have it, the bearings all fit nice and tight, but because it was the cheapest bearing kit, the bearings feel....well, cheap.  They don't spin very well at all, but the linkage will articulate - and tightly at that.



Here is how the bike currently sits.  Bearing kit was $38 shipped.  So we are at $988 total.  Hot damn, still under a grand.