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Best way to clean out CR250 engine

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My piston just recently blew up. And tons of shards are inside my engine. I took the whole thing apart. Now the question, What is the best way to clean it out? How would you do it?

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when I bought my cr80 it had a broken skirt so took the top end off and tipped the motor upside down and started cranking it to get the shards out, just make sure every thing comes out and that it didn't cause any damage .

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My piston just recently blew up. And tons of shards are inside my engine. I took the whole thing apart. Now the question, What is the best way to clean it out? How would you do it?

What do you mean you, "took the whole thing apart."

To make sure I would split the cases, because I would not want a piece of metal messing up my new top end. That's what I would do, but I suppose tipping it upside down would work to? :thumbsup:

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Parts washer.

You can get a benchtop one for about $35, or just make one with a 5-gallon pail for free.

I have one of these, and I use straight diesel it it as the solvent (low flash point, and effective for removing grime, oil, and debris)

388px-Parts_washer.jpg

I wish i had this model with the leggy blonde... :thumbsup:

model-t20-parts-washer.jpg

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@downonmonday, i ordered a whole new crank kit and piston kit from wiseco. Just waiting on my case splitter tool. so i have it stripped down with the engine out. Thats what I mean by apart. But would compressed air actually be enough dubkatz? Bieng that there is oil in the engine from a leaky crank seal. The shards should stick to the walls. So maybe desiel like phuz said?? Another question. I am about to "try" and put the bearings on the crank. I put the crank in the freezer. And here is the question; Can I put the bearings in the oven to expand them? If so what temp would be safe and ideal? And for how long could/should I leave them?

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@ymazuki20, I have to split it anyway because of the Wiseco crank and piston kits I ordered and have to install. But I had a leaky crank seal because I installed it lop sided. So there was oil being pushed into the engine. Now those shards would probably stick to the walls really good because of the oil. So I figured I would need some kind of solvent or something to absolutely make sure I got everything out! SO I don't end up having to buy a whole new set up again! Expensive man!

Example: There are some spots that you can't reach with just your hand and a rag in the cylinder. Probably other spots just like that.

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dude you need to use dawn and a paper towel to clean all metal parts until the paper comes out white

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Parts washer and diesel does wonders man!! Thanks Phuzz. Well I had to wait a week and a half just for the case splitter. I split the case without taking the flywheel off. I tried to do the rebuild without taking off the flywheel(Can't take the crank out), Not going to happen. So is there an alternative to ordering the flywheel puller and waiting another 2 damned weeks? Because it's been a month since I rode and I'm jonesing. Maybe a homemade FWP? Maybe some prying?

Edited by Annonymous

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jsus christ...

wash out the crank case with fuel. swish it all around and rotate the crank.

rinse and empty 8 times, then wipe out with paper towels.

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jsus christ...

wash out the crank case with fuel. swish it all around and rotate the crank.

rinse and empty 8 times, then wipe out with paper towels.

Dang, someone pissed in your cheerios.

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all good. just so surprised that this method was not the first one mentioned.

its pretty straight forward ansd simple.

the only other complete way is to split the cases.

good luck!

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Order your parts from rockymountainatv.com I get my parts or tools by the end of the week at most, and usually 3 days. Free shipping on orders over $100. Seriously I can get my tools before a local shop puts the order through.

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the best way to clean out the bottom end is to tell charlie sheen that there is 7 grams of coke in your crankcase..then hand him a straw.

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All these ways are good to get pieces out of a crankcase that you are not splitting apart. Let me throw out another way. Turn the engine upside down and hose out the crankcase with a garden hose as you are rotating the crank. As the water is gushing out, it will carry the pieces with it as long as it is still upside down and you are rotating the crank. Turn the engine back rightside up. Fill the crankcase with gas to displace the water. Slosh it around and dump it. Fill again with premix, slosh it around and dump it. This lubes all the bearings.

With that being said, if everyone will pay attention, HE IS SPLITTING THE CASES TO REPLACE THE CRANK!!!! Forget about trying to flush all the pieces out. Get the crank out, then the crankcase on a 2 stroke is smooth metal. Wipe out the oil film and metal, use a parts washer or some gas on the crankcase. Make sure all is clean, and reassemble.

You will need the flywheel puller and I would get a crank puller too. Install the bearings in the case halves, not on the crank. Put the bearings in a deep freeze overnight, put the case halves in an oven at 200 degrees for about an hour. The bearings will drop right in if you are quick. Then you need the crank puller to pull the clutch side of the crank into the bearing. You are messing with the bottom end of an engine, get the right tools. Start prying on stuff and you will be headed down a long road of parts failing and trashing other new parts. Look at it this way, the price of the tools is way cheaper than a shops labor charges. I also recommend the Tusk tools from rockymountain for these pullers.

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In my previous post, I stated I cleaned it out with a parts washer and diesel Thestuz. I ordered the crank case splitter from ebay. I split the case and removed the crank. Pulled the flywheel with the flywheel puller. Now the freaking bearings are stuck in the case really tight!! I put in a snug socket and hit it with a rubber mallet. No luck. Didn't even move a CM. I was told I am going to have to go to a shop and have them pressed out. I would have really liked to been able to remove them myself!!! Has anyone done this themselves?

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