250R keeps having coolant in crankcase.

[rmcollector]

Morning all, I can't seem to get my 1985 250r running right, this is my second time replacing the head gasket. The reason I replaced it the first time is because it was overheating and the coolant was bubbling, after removing the top end there was coolant in the crankcase which led me to believe the head gasket was blown. After replacing the head gasket for a second time, it started on second kick and I got about 1-2 min of good run time, then with the radiator cap off while it was running briefly, it sucked down coolant and then started running really rough and then it stalled out. Attempting to kick start it after it stalled, it shot coolant out of the radiator. After removing the top end for a second time now, there is coolant in the crankcase again.


Before all of this, I replaced the head gasket and torqued it back down to spec, a compression and a leak down test was performed both times. Leak down passed fine both times. Compression is at 176-180 both times. Cylinder was bored about 10 hours ago and it looks great and smooth and replaced with wiseco piston. Crankshaft is solid, no up and down movement. First time the head gasket was replaced it was replaced with oem metal head gasket, second time it was replaced it was replaced with tusk metal head gasket. Cylinder head has very low hours on it, but I did check it and it is flat with no gaps at all.

I also replaced the water pump impeller with new seals and gaskets. Radiator was cleaned out to ensure nothing is in the way. New radiator cap as well.


Not sure where else to go here. Any ideas would be appreciated.

[TexFest]

Use some copper gasket spray on your head gasket maybe and see what happens?


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[rmcollector]

Yeah it was used on both head gaskets that I installed.

[yaegerb]

You need to either deck or hand lap your cylinder head/cylinder. See my how to below if you want to try hand lapping. Otherwise take it to a reputable machine shop.

Lapping thread:

http://www.3wheelerworld.com/showthread.php/173994-ATC-250R-coolant-leak-leads-to-enlightenment-Hand-Lapping-and-Time-Serts?highlight=Leads+to+enlightenment

[rmcollector]

You need to either deck or hand lap your cylinder head/cylinder. See my how to below if you want to try hand lapping. Otherwise take it to a reputable machine shop.

Lapping thread:

http://www.3wheelerworld.com/showthread.php/173994-ATC-250R-coolant-leak-leads-to-enlightenment-Hand-Lapping-and-Time-Serts?highlight=Leads+to+enlightenment

Good info for sure, I took the head and cylinder off and brought the head inside on some granite. It is not flat, I was surprised being it has pretty low hours...but I guess you never know. Will get a feeler gauge. I ran a straight edge on the cylinder and it is off as well. I am going to follow your method you provided in your article and see if that works.

I'm having trouble getting the stud bolts off, im doing the 2 nut method to try to get the studs to turn, but nothing. I don't want to use too much force so they don't break. Any tips for this problem?

[TexFest]

Good info for sure, I took the head and cylinder off and brought the head inside on some granite. It is not flat, I was surprised being it has pretty low hours...but I guess you never know. Will get a feeler gauge. I ran a straight edge on the cylinder and it is off as well. I am going to follow your method you provided in your article and see if that works.

I'm having trouble getting the stud bolts off, im doing the 2 nut method to try to get the studs to turn, but nothing. I don't want to use too much force so they don't break. Any tips for this problem?

I used one of those bernzomatic torch with a yellow bottle and penetrating fluid to get studs out that wouldn’t budge


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[shortline10]

A stud extractor is a must .
https://www.ebay.com/itm/393097016915?epid=1829100976&_trkparms=ispr%3D1&hash=item5b86687653:g:-wkAAOSwFLhgAWYx&amdata=enc%3AAQAFAAACgBaobrjLl8XobRIiIML1V4Imu%252 Fn%252BzU5L90Z278x5ickkyMJZWL%252BqFSgQ3TOOe%252FN r7hJUvxWbl9qbR7O9QBMHarw%252B%252BvGD4GS4AsAhrhJ8o EPzTsbr5u3M%252F4fjjvpaGYLX3aK3m2UBqOayU8AlS1wz%25 2BRH%252FYkg6IrZy%252F30h0LOnQOr5IoWwSNBG55LVBJqhH 44wR7AAanOgUVr47nFxG1d5bngIF8n%252BTlXYaPQUAw2tG%2 52Fp9yWXn%252F7UG9bS8R4RWrS4%252F2LjneWRCsKsMttOOk auZtBZcGRcLPt3RPxEaHp%252FSJiGUMSYPFU5rCvyJ8UwzX9K W9o9GshIBjdarfahyifCCn8hQqiV5bb4cSq6Z5ep97mszlpNO0 DszFm7X4EyFSK%252F8c3jGhURivF2%252FnON6yVl%252BP3f UUU8RyMyeGa1OZAtQmwxHTYLachT9zdhnIs7qbGgwwSljuoJB8 hPkghhISIgUvSvSXbHhE5T8y2gzg9MTyWjVdl%252FcOLaHl3V MU7j4a4IZcVLF29HCfOhfV57YeAS1llm3qkOsX3%252Fk%252F Vf4pfF%252FXwtThjR2ionhGXgwQVfFujW%252FBPAXYD7gDgu Qet9%252BtFxNE4U9W9OW%252FnDbjzDg%252F24zpVXV%252B ZgvI5MMDf7ulNozIpgvp0GLvnFhSHR%252BoogekFtoRaUDP8I PDEhwgLWRfkB%252FYdyFGSlGXsA9j8%252FWRQLTwLzZgbx5% 252FxOp9M%252BMx%252FUsVT%252BmKeoQC90zzB5aK7XtPr9 UJB8dc%252BK%252F1tu%252BTo0cAEj05h7zOng86qGKaUQ5g WYm80ko0kB2Nhq64hWXlQqeNQOSpcYKOTQAy%252BSj1Q2wtxq yTnQNgJ%252B56iBV6pHL%252BdHS8l8PoBw%253D%7Ccksum% 3A393097016915cc116451462e4a73b0ca3154a2655db3%7Ca mpid%3APL_CLK%7Cclp%3A2334524

[rmcollector]

A stud extractor is a must .
https://www.ebay.com/itm/393097016915?epid=1829100976&_trkparms=ispr%3D1&hash=item5b86687653:g:-wkAAOSwFLhgAWYx&amdata=enc%3AAQAFAAACgBaobrjLl8XobRIiIML1V4Imu%252 Fn%252BzU5L90Z278x5ickkyMJZWL%252BqFSgQ3TOOe%252FN r7hJUvxWbl9qbR7O9QBMHarw%252B%252BvGD4GS4AsAhrhJ8o EPzTsbr5u3M%252F4fjjvpaGYLX3aK3m2UBqOayU8AlS1wz%25 2BRH%252FYkg6IrZy%252F30h0LOnQOr5IoWwSNBG55LVBJqhH 44wR7AAanOgUVr47nFxG1d5bngIF8n%252BTlXYaPQUAw2tG%2 52Fp9yWXn%252F7UG9bS8R4RWrS4%252F2LjneWRCsKsMttOOk auZtBZcGRcLPt3RPxEaHp%252FSJiGUMSYPFU5rCvyJ8UwzX9K W9o9GshIBjdarfahyifCCn8hQqiV5bb4cSq6Z5ep97mszlpNO0 DszFm7X4EyFSK%252F8c3jGhURivF2%252FnON6yVl%252BP3f UUU8RyMyeGa1OZAtQmwxHTYLachT9zdhnIs7qbGgwwSljuoJB8 hPkghhISIgUvSvSXbHhE5T8y2gzg9MTyWjVdl%252FcOLaHl3V MU7j4a4IZcVLF29HCfOhfV57YeAS1llm3qkOsX3%252Fk%252F Vf4pfF%252FXwtThjR2ionhGXgwQVfFujW%252FBPAXYD7gDgu Qet9%252BtFxNE4U9W9OW%252FnDbjzDg%252F24zpVXV%252B ZgvI5MMDf7ulNozIpgvp0GLvnFhSHR%252BoogekFtoRaUDP8I PDEhwgLWRfkB%252FYdyFGSlGXsA9j8%252FWRQLTwLzZgbx5% 252FxOp9M%252BMx%252FUsVT%252BmKeoQC90zzB5aK7XtPr9 UJB8dc%252BK%252F1tu%252BTo0cAEj05h7zOng86qGKaUQ5g WYm80ko0kB2Nhq64hWXlQqeNQOSpcYKOTQAy%252BSj1Q2wtxq yTnQNgJ%252B56iBV6pHL%252BdHS8l8PoBw%253D%7Ccksum% 3A393097016915cc116451462e4a73b0ca3154a2655db3%7Ca mpid%3APL_CLK%7Cclp%3A2334524

I bought a stud extractor today at the hardware store, it didn't work. It's slipping when turning. I applied some heat and still nothing. The studs have been soaking in pb blaster as well but it's not helping.

[shortline10]

Are you sure you bought the correct size m8 or possibly just a cheap one ?
Mine will grab to the point were I could break the stud , never slips .

[rmcollector]

Are you sure you bought the correct size m8 or possibly just a cheap one ?
Mine will grab to the point were I could break the stud , never slips .

This is the one I bought from advance auto, says it grabs 6mm to 12mm. https://shop.advanceautoparts.com/p/autocraft-stud-extractor-3-8-ac4556/11632013-P?searchTerm=stud%20extractor

The one you have is the one you gave me a link to?

[sledcrazyinCT]

This is the one I bought from advance auto, says it grabs 6mm to 12mm. https://shop.advanceautoparts.com/p/autocraft-stud-extractor-3-8-ac4556/11632013-P?searchTerm=stud%20extractor

The one off ebay can also be bought in a 4 piece set from a place like harbor freight if you have one local

The only stud extractor I have seen that fits a range of diameters is one of these. https://aboloxtools.com/Williams-S-60E?msclkid=060c2102464510cea7304193a9718ae7&utm_source=bing&utm_medium=cpc&utm_campaign=**LP%20Shop%20-%20Socket%20Drivers&utm_term=4587780991107662&utm_content=JHWS-60E%20%7C%20Williams%20JHWS-60E%201%2F2%22%20Drive%20Stud%20Remover%20%7C%20%2 433

[TexFest]

I bought a stud extractor today at the hardware store, it didn't work. It's slipping when turning. I applied some heat and still nothing. The studs have been soaking in pb blaster as well but it's not helping.

How long did you leave the heat on it? I heated it up for 5 minutes non stop


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[shortline10]

Yes it’s similar to the one I sent you a link .
They are definitely specific in size , 8mm only .
The more pressure you put on it the tighter it gets , no slipping .

[rmcollector]

How long did you leave the heat on it? I heated it up for 5 minutes non stop


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I used about 1-2 min of heat, I will try it again with more heat and see what happens. If it doesn't remove it this time I will return the one I have and go with the KD Tools 8MM Stud Remover or something similar. I'm not seeing anything at Harbor Freight.

[yaegerb]

I used about 1-2 min of heat, I will try it again with more heat and see what happens. If it doesn't remove it this time I will return the one I have and go with the KD Tools 8MM Stud Remover or something similar. I'm not seeing anything at Harbor Freight.

Don’t go cheap on stud pullers. OTC makes a really nice set on Amazon.

Sounds like you are finding out that your surfaces aren’t true. That happens after 30+ years of use. Also, your other problem with coolant in the crankcase. The only thing I can think of is that you mechanical water pump seal has failed. When installing them they are a 1 shot deal so if you don’t do it correctly you have to start all over. My guess is that’s where the coolant is coming from.

[shortline10]

I assumed the way he explained the coolant issue that he was talking about crank cavity and pressures from their and not the crankcase transmission cavity .
Do you have coolant in your transmission oil ? If yes it’s time to rebuild the water pump .

[yaegerb]

I assumed the way he explained the coolant issue that he was talking about crank cavity and pressures from their and not the crankcase transmission cavity .
Do you have coolant in your transmission oil ? If yes it’s time to rebuild the water pump .

Ah, good point. I assumed transmission.

[big specht]

I’m pretty sure he said he already done that. Even so there are such things as bad new parts. We all been there

[rmcollector]

I’m pretty sure he said he already done that. Even so there are such things as bad new parts. We all been there

That's correct, it was replaced. Before it was replaced there was no coolant in the transmission. I went ahead and replaced the water pump anyway because I had the new parts in the shop.

[rmcollector]

Finished up over the weekend, head and cylinder came out great and flat. Passed a leak down test. Compression is at 176-180 psi. Started on 2nd kick and sucked a bunch of coolant down again and stalled out less than 10 seconds or so. It won't fire back up because the coolant is in the crankcase. I'm at a loss and have no idea where the problem is.

[shortline10]

I’ve run into this a few times were their were hair line cracks in the cylinder / water jackets , only leaked under combustion .
If your sure the head and cylinder are mating good ?
Are you using an OEM or Oem style head gasket the thick one ?
Some of them aftermarket ones are junk .

[rmcollector]

I’ve run into this a few times were their were hair line cracks in the cylinder / water jackets , only leaked under combustion .
If your sure the head and cylinder are mating good ?
Are you using an OEM or Oem style head gasket the thick one ?
Some of them aftermarket ones are junk .

Yeah im starting to question whether the top end is good, passes leak down tests and has good compression, but fails under combustion. I used the Honda oem head gasket the first time and this time I used the metal tusk head gasket. Both gave me the same result.

[yaegerb]

Yeah im starting to question whether the top end is good, passes leak down tests and has good compression, but fails under combustion. I used the Honda oem head gasket the first time and this time I used the metal tusk head gasket. Both gave me the same result.

When you say leak down test, I assume you are referring to a crank case pressure test NOT an four stroke leak down? Secondly, if you are performing a crank case pressure test what are you pumping the pressure up to and for how long?

Have you performed a visual inspection of the cylinder for cracks? Your surfaces are either not flat enough or you have a crack somewhere.

[rmcollector]

When you say leak down test, I assume you are referring to a crank case pressure test NOT an four stroke leak down? Secondly, if you are performing a crank case pressure test what are you pumping the pressure up to and for how long?

Have you performed a visual inspection of the cylinder for cracks? Your surfaces are either not flat enough or you have a crack somewhere.

Yes, I am running a crank pressure test, pumping it up to 10 psi for 15 min-20 min just to make sure nothing is leaking. Nothing at all is lost and it holds exactly to what I pumped it up to. No, I didn't check the cylinder for cracks, just made sure it didn't have any scoring going on.

Let's say the surfaces are not flat, wouldn't it leak out of the cylinder head once it's started just briefly because of the pressure?

I guess im going to have to take it back off to inspect it for cracks.

[yaegerb]

Yes, I am running a crank pressure test, pumping it up to 10 psi for 15 min-20 min just to make sure nothing is leaking. Nothing at all is lost and it holds exactly to what I pumped it up to. No, I didn't check the cylinder for cracks, just made sure it didn't have any scoring going on.

Let's say the surfaces are not flat, wouldn't it leak out of the cylinder head once it's started just briefly because of the pressure?

I guess im going to have to take it back off to inspect it for cracks.

Yes, it should leak around the head gasket top deck mating surfaces. 10-15lbs? That's way too much. I am surprised you didn't blow your crank seals. You might want to check to ensure those are still seated.

[rmcollector]

Yes, it should leak around the head gasket top deck mating surfaces. 10-15lbs? That's way too much. I am surprised you didn't blow your crank seals. You might want to check to ensure those are still seated.

No, 10 psi was the max for 15-20 min. I am getting no leaks anywhere around the head gasket mating surfaces. I am going to take it back off sometime this week to have a look for possible cracks in cylinder somewhere. If it has a hairline crack somewhere can a reboring be done or is the cylinder no good?

[yaegerb]

No, 10 psi was the max for 15-20 min. I am getting no leaks anywhere around the head gasket mating surfaces. I am going to take it back off sometime this week to have a look for possible cracks in cylinder somewhere. If it has a hairline crack somewhere can a reboring be done or is the cylinder no good?

The crack would be in a water jacket or other aluminum area. Has really nothing to do with your iron sleeve. Take your time and look carefully. If you find the crack I would send to rob selvy as he can weld damn near anything on these engines.