Got my first dirtycycle!

[REXXX]

soak the s.a. bolt in PB? that shit is mind blowing sometimes.

I agree, just keep stripping and cleaning what you can. I know it sucks but you may be able to get that thing back in shape fairly easily. time wise, no. dough wise, possibly.

crazy the skirt shattered but it sounded like you didnt run it long once it failed (?)

dirt bikes rock, right? got one down myself, that's why you keep two!

The engine seized as soon as it shattered. There is even a piece in the reed valve which i still have to take out. I just had to step away and eventually buy some penetrating oil for the s.a. bolt and find a heavier weight hammer. I also forgot to take off the countershaft sprocket when the engine was together and i don't have the proper size socket. this'll be fun.

[typeone]

bigger hammers always work

ah, cs sprockets that bolt on... i remember those. i'm fancy now with one retainer clip.

hope you can get it cleaned up!

[Paul_E_D]

Keep at it. You "can" split the cases without the tool. Maybe the metal wedged in there will help em come apart!?

[breakdirt916]

want to learn? keep it and disassemble it

otherwise, in my humble opinion, it's a financial blackhole...part it out. Unfortunately in this economy part-outs aren't as profitable as they used to be

[typeone]

financial blackhole

aka : motorcycling

[Kurlon]

want to learn? keep it and disassemble it

otherwise, in my humble opinion, it's a financial blackhole...part it out. Unfortunately in this economy part-outs aren't as profitable as they used to be

It's not an old suzuki... not a blackhole yet.

[csmutty]

It's not an old suzuki... not a blackhole yet.

Like a certain rm125? hehe.

[breakdirt916]

pfft...that's the last time I ever buy a suzuki!

how about this: Rexx - what's your budget?

I can help you make a list - then decide. Don't spend a little, start a repair, spend a little more...then stop...or worse, spend more until you've spent too much.

deal?

Just a headsup: this can easily cost you over half of what you've already spent to buy the bike

[Kurlon]

Yeah, it could... but that's not very likely. Your zook cost so much because it's a zook, and it was much older, and in far worse shape to start with. I started with a similar era Yamaha, in similar condition to yours, I guarantee even with my insistance on stuff being done right or better (Why replate when you can go ported big bore for twice as much?) I spent less on my WReck thanks to Yamaha's parts bin mentality.

Once you've got it out, split that puppy. You don't need special tools, gentle persuasion with a rubber mallet on the shafts/crank while pulling on the cases will slowly, safely separate them. At that point you can fully evaluate the engine. I'm going to wager on the just need a top end and maybe some gaskets for the lower end option as the end result.

[csmutty]

Yeah, it could... but that's not very likely. Your zook cost so much because it's a zook, and it was much older, and in far worse shape to start with. I started with a similar era Yamaha, in similar condition to yours, I guarantee even with my insistance on stuff being done right or better (Why replate when you can go ported big bore for twice as much?) I spent less on my WReck thanks to Yamaha's parts bin mentality.

Once you've got it out, split that puppy. You don't need special tools, gentle persuasion with a rubber mallet on the shafts/crank while pulling on the cases will slowly, safely separate them. At that point you can fully evaluate the engine. I'm going to wager on the just need a top end and maybe some gaskets for the lower end option as the end result.

This shouldn't cost too much and will be better than rolling the dice with another used bike where the motor might do the same thing..

[gregp]

I frequent NewEnglandDirtBikes.com (NEDB) and it is a good forum, with a lot of knowledgeable folks. If you are on Facebook, search for RMD (Rec.Motorcycles.Dirt). And then there is Adventurerider.com - they have a lot of information for any bike.

[REXXX]

my budget is yet to be determined. Once I get the motor out I'll look into splitting the cases and then judging what it'll need from there. Then just saving money to buy what it needs the first time around.

[gregp]

FWIW - I have "saved" motors in worse condition. Yes, the crank bearings are all seized up from all of the aluminum chunks, but that does not mean that they are wasted. Remove the motor from the frame, and fill the crank with gas or kerosene, and work the crank back and forth. Eventually you want to flush all of that crap out of there. Do this a couple of times. Your cylinder actually looks usable to me. Pop a new piston and ring in there, and you will probably be good to go.
Aluminum is soft, compared to the ring material or the crank bearing material, so you will probably be OK if the rings are in one piece, and if no bearing ball retainer parts flush out.
FWIW - It is important to understand that this happened because the piston was well over its service life. If you had simply installed a new piston upon buying the bike (as previously mentioned here), all of this would have been avoided.

[Kurlon]

Worst case, we should plan a wrenching party in NH some time, get a bunch of dirty bikes needing TLC together and go to town on them.

[breakdirt916]

Yeah, it could... but that's not very likely. Your zook cost so much because it's a zook, and it was much older, and in far worse shape to start with. I started with a similar era Yamaha, in similar condition to yours, I guarantee even with my insistance on stuff being done right or better (Why replate when you can go ported big bore for twice as much?) I spent less on my WReck thanks to Yamaha's parts bin mentality.

I guarantee you spent a lot less...but wasn't the Eric Gorr work = the cost of the bike?

and how good is the Yamaha parts bin mentality? I'm tempted to buy another 2-smoke based on how available and how cheap maintenance costs are. I'm almost neglecting the initial purchase price in favor of lower ownership/maintenance costs. If Yamaha is truly as cheap as they say, then a YZ125/250 is a good option for me. I have a Yamaha street bike too, and f'n love it.

Rexx: I'll be the sole accountant here to get you started...

$35 shipped - gaskets
$55 shipped - crank bearings
$95 shipped - top end (piston, rings, circlip)
$110 shipped - crankcase splitter, and crank puller **you may or may not need this...I went without it, and damaged the threads on the crankshaft trying to push it out. I also tweaked the crank bearings since I split them at an angle, and I couldn't get the "freezing then installing" trick to get the crank into the bearings. But I also suck. So if you're handy, you can probably do without it. If you want to go the middle of the road, get the crank puller. That was one thing I couldn't do without.
$20 shipped - flywheel puler
$199-$262 - cylinder re-plate
$30 coolant change, transmission fluid change
------------------------------------------

Assuming you don't buy the crank puller/case splitter, and it's only $199 to re-plate, you're looking at $434. Add the tools and it's $544.

This also assumes all the parts inside the case are in good shape...when my crankcase exploded, it was because a transmission bearing had failed. Worse yet, it was a blind bearing removal (so essentially, it was the bearing that was hardest to get to, and least likely to be replaced). So if you *really* want to do it right, inspect all the transmission bearings when it's split apart and replace those as needed (which may be up to another $150). How does your transmission shift? I also like to spec the transmission spacers and washers while the transmission comes out; and replace all of them for good measure and keep her shifting on point.

I also don't know how the cooling system works on a YZ250, but it's likely there's an impeller in there somewhere that people NEVER replace. It likely has grooves all around it into the bearing, and the seal could potentially fail with the cases being split, then put back together. It might be good measure to replace that impeller and the seal. Also, take a good look around the cases...are the seals for the gear shifter in good shape? Mine was slightly bent since the bike was dumped on the shifter, so I had to have the case machined to re-round the hole, and a new seal burned in to stop the slow leak. btw, how does your air filter look? Most people don't clean them...or change them...ever. I'm pretty sure the clumpy chunk POS in my airbox was the original filter.

[Kurlon]

Welp, some quick tidbits on Yamaha raping the parts bin:

250 Cases - Two generations, 89 to 1998, 1999 to current. Stay within the generation and it's mix'n match city. Unlike some other brands, Yamaha is confident enough in their machining to sell case halves separate, you're not required to buy them in a set to have them work together. Extra bonus points, the old generation cases will fit in new generation frames directly if you swap the swingarm pivot sleeve with the new one. You have to monkey with the exhaust and carb fitment at that point, but still, 89 engine, 2013 frame, bolt, up.

Wheels - Only a few variations here, match the axle size and use the spacers from whatever year forks/swingarm you're using and they'll drop in. 125s and 250s play in this same sandbox, along with the MX thumpers.

Want to lighten your modern YZ250, YZF450 swingarms drop in and save some weight... I can go on and on. It's darn near silly how much swaps amongst these things.

Hence why I love my eBay special.

[gregp]

.. Or, if the OP is a recreational trail rider, fix the YZ, as inexpensively as possible, and sell/trade it in for a nice 1995+ KDX200. They are plenty fast, and one of the most reliable and capable trail machines ever made. Even though they have been discontinued, there are plenty of them out there, some barely used, for cheap money.

[breakdirt916]

^^ imho - that entirely depends on the crank being able to break free, and the engine to run. With bits of the piston skirt in the bottom end, I don't feel too confident in that happening. We don't even know which part of the lower end is being frozen up...is it the bearings? are they wedged between the crank and the engine block?

but if it does work, than it's the cheapest option here...so I'm okay with that. But it's still a gamble of ~$125 with a new top end and fluid changes.

[REXXX]

I bought a YZ250 because I wanted to ride track and trails. It was working well on both for me and if I was to get a dual purpose again it would be another drz400sm and get some dirty wheels for it too.

I was just reading on what possibilities could cause the piston skirt to shatter:
"Shattered Skirt
The skirts of this piston shattered because the piston to cylinder clearance was too great. When the piston is allowed to rattle in the cylinder bore, it develops stress cracks and eventually shatters."

It doesn't say anything as to what would be factor for having to much clearance. I dont have any measurement tools to see what is/was out of spec. Hopefully a co worker remembers to bring in a hammer for me in the morning so I can get the motor out of the frame. I then will try and find pieces, cleaning, seeing why the coolant turned brown, shop around for tools.

[Kurlon]

Don't overlook one of the most common causes of shattered skirts... too many hours on the piston.

[REXXX]

I went with that the dude saying it had 10 short rides on a new top end...

[Kurlon]

Heh, my WR supposedly had a 'recent top end' too... It ran Ok, other than I knew the power valve wasn't opening as it wouldn't come on the pipe with any hit. Inspection revealed it was a bit more... gone. The power valve was eating the side of the piston, the ring had gone on walk about and was eating the cylinder...

Still had ok compression though, no weird noises either.

[typeone]

used 2 strokes ALWAYS have a 'recent top end' and 'low hours'

i'm helping my neighbor go through his 'extra clean' '02 CR. he's not liking my emails explaining what to inspect and strip down... the whole bike. hahaa

[breakdirt916]

I got lucky too! mine only had like 20 mins on it!

guy claims he rode it once, and got off because it was too fast...faster than his friends KX500!

did anyone else's bike come with a new power band?

don't worry rexx...w' a used 2-smoke under $1,500, there's always that risk. My experience is that most owners are "recreational trail riders" looking to ride it until it grenades, or worse yet kids with no have money to maintain it, and don't even know how. I once saw a craigslist ad post about 2-3 times about a kid who was looking for a good mechanic to fix the clutch on his XR200R. Engine revved find, but bike didn't go anywhere fast. Only problem? he only had $20, including parts and labor to fix it...can anyone do it?

[slowkermit]

If a bike doesn't have an hour meter on it, or a detailed maintenance log, I'm not listening to a word from the previous owner. It gets a new top end, new air filter, carb inspection/cleaning, oil change, and a powervalve cleaning. Total cost under $250 and total time invested 4-6hrs. Then you have a better idea of what you own.