CRF250 Stripped oil drain bolt.

3rdgearpinned
Profile picture for user 3rdgearpinned
Posts
526
Joined
7/8/2016
Location
In the Mountains, NC US
3rdgearpinned
Edited Date/Time 10/12/2017 9:09pm
just got this bike. Noticed on the first oil change that the bolt had some metal shards on it. 2nd oil change went ok but it felt soft to tighten. Now, shes done. Wont tighten at all. Whats the best option? I've never tapped or done a helicore but it looks as if the threads on this bike do not start until further up in the hole. Anyone with a similar problem?
|
Acidreamer
Profile picture for user Acidreamer
Posts
1794
Joined
8/25/2015
Location
Mansfield, OH US
Acidreamer 10/12/2017 5:41pm
10/12/2017 5:41pm
Install a timesert. Its a bit better than a helicoil. I just went through this on my kx. Previous owner installed a helicoil and it doesnt hold the oil at operating temp. Had to use that white plumbers tape to fix it. A timesert looks more permanent and doesnt have a bunch of little slits oil can pass through. That being said tons of people still have good luck with helicoils.

As far as tapping, youll want to use the correct tap drill. Get some tap lube or wd40 and turn the tal in as straight as possible. Go 2-3 turns and then back put, go 2-3 turns again, back out, until youre at the depth of threads you need. If it starts binding just back the tap out, clean it up and put more lube on. Pretty simple.
3rdgearpinned
Profile picture for user 3rdgearpinned
Posts
526
Joined
7/8/2016
Location
In the Mountains, NC US
3rdgearpinned 10/12/2017 7:07pm
10/12/2017 7:07pm
Acidreamer wrote:
Install a timesert. Its a bit better than a helicoil. I just went through this on my kx. Previous owner installed a helicoil and it doesnt...
Install a timesert. Its a bit better than a helicoil. I just went through this on my kx. Previous owner installed a helicoil and it doesnt hold the oil at operating temp. Had to use that white plumbers tape to fix it. A timesert looks more permanent and doesnt have a bunch of little slits oil can pass through. That being said tons of people still have good luck with helicoils.

As far as tapping, youll want to use the correct tap drill. Get some tap lube or wd40 and turn the tal in as straight as possible. Go 2-3 turns and then back put, go 2-3 turns again, back out, until youre at the depth of threads you need. If it starts binding just back the tap out, clean it up and put more lube on. Pretty simple.
This sucks ass but thanks for the time. I'm pretty mechanical but I'm not sure I can do it. I certainly don't want to think about the fact that there may be shavings up in the case as it is. Where did you get your tap kit and other things? Thanks again.
Paw Paw
Profile picture for user Paw Paw
Posts
679
Joined
12/24/2011
Location
Benton, LA US
Paw Paw 10/12/2017 7:14pm
10/12/2017 7:14pm
Look these drain sections of the case are very thin and with almost no support for drilling, tapping or inserts. In most cases they just will not hold. So with that said....
You really only have a couple of good choices.
1. New cases
2. Engine tear down with welding and then drilling and tapping.


Paw Paw
FGR01
Profile picture for user FGR01
Posts
5112
Joined
10/1/2006
Location
AZ US
Fantasy
1222nd
FGR01 10/12/2017 8:54pm
10/12/2017 8:54pm
If you absolutely have to have it fixed perfect, do what Paw Paw says. However, that is the expensive way. If you are on a budget do a timesert. The trick to avoiding shavings in your oil is to use grease on the tap. It will catch and hold the shavings. Is this in the engine oil drain or the tranny oil drain?

The Shop

See All »
3rdgearpinned
Profile picture for user 3rdgearpinned
Posts
526
Joined
7/8/2016
Location
In the Mountains, NC US
3rdgearpinned 10/12/2017 9:07pm
10/12/2017 9:07pm Edited Date/Time 10/12/2017 9:09pm
FGR01 wrote:
If you absolutely have to have it fixed perfect, do what Paw Paw says. However, that is the expensive way. If you are on a budget...
If you absolutely have to have it fixed perfect, do what Paw Paw says. However, that is the expensive way. If you are on a budget do a timesert. The trick to avoiding shavings in your oil is to use grease on the tap. It will catch and hold the shavings. Is this in the engine oil drain or the tranny oil drain?
The oil drain, underneath. Most of the time paw paw has the best idea. It's not always the cheapest. However, with the 18's coming out with electric start, and me getting ready to turn 45 I ain't splitting the case.

However, paw paw is correct in it being not enough to tap. You see, there is a small hole before the threads start. You can tell that the wall on that side is not thick at all.

The top 1/3 of the hole has good threads while the bottom 2/3 is junk. I was able to find another Honda bolt that was the same size and same thread pitch but longer.

It's in and tight. I filled it with oil and will let it sit overnight. If it's dry tomorrow I will put a new filter in and fire it up and pray that no shavings got up in the motor.

2 counteract that as best as I could (because I saw shavings in the threads and a lot) I left the oil drain bolt out and filled the entire crankcase way overfull 4 times and let it drain. Probably used a gallon of new oil. After that I took Q tips and cleaned the damaged threads.

Then I ran another 1400ml through it. Just to be sure. The bolt is tight. Or rather I say, snug but not going anywhere. Here's a pic of that hole I was talking about.

sandman768
Profile picture for user sandman768
Posts
6071
Joined
3/21/2014
Location
Saratoga Springs, NY US
sandman768 10/13/2017 5:41pm
10/13/2017 5:41pm
been there on 450 Honda , side drain bolt under the shifter. Made a thread chaser out of a same size new bolt, ran it & out with grease on it a few times, used another new Honda bolt that was about 4 mm longer, there were deeper threads within the case to use a longer bolt. I replace crush washer every few oil changes & use proper tourqe spec on the bolt, it's not a lot of pressure.held up fine, ...I also start all oil drain bolts by hand.

Post a reply to: CRF250 Stripped oil drain bolt.