Stihl MS290 Rebuild Problems/Questions

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Fog1965

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I am in the process of rebuilding an MS290 to correct damage caused by ethanol. I have a new engine and have disassembled everything that I need to. All that is left are the four bolts that hold the engine together and to the plastic frame/chassis/crankcase (depending on where you look as to what is called). I removed one OK, one of the ones in the open on the outside. When I went to removed the second one, which is down a square hole (naturally), the head twisted off the socket and is wedged in the bolt. It is one of the torgue (sp?)/star bolts.

It appears to have been over tightened at the factory, and in checking the other two they are also over tightened. The factory specs call for 11 Newtons or 8.3 ft/lbs to tighten and I applied well over 30 ft/lbs trying to loosen then. I know that this saw has never seen a torque wrench as it went down the assembly line, most liked air drills.

So, I have two problems. The first is the broken part of the socket imbedded in the screw. I have managed to drill out part of it, but so far have not been able to clear the remainder. I am getting close to just drilling the head off the bolt so I can pull it through the frame/chassis/crankcase - and then tackle the other two. If anyone has some experience with this problem, I will be most interested.

The second problem I am facing, is if I do wind up having to drill the head off the bolt then I have to remove the bar stud that threads into the engine. I checked with Stihl on the "special tool" that they have to remove it and was quoted a price of $82-$84 for it. With a number of people having rebuilt these, what is the method used to remove the bar stud without having to give Stihl another $84.

Any information and previous experience in these issues will be greatly appreciated. The patience is starting to wear thin with this thing, I am convinced that it was either built on a Friday or Monday - either getting ready for the weekend and not caring or with a hangover from the weekend and caring even less.

Thanks,
Fog
 
Not a 290 person, but by bar stud, do you mean one of the studs that the saw bar bolts on to? If so, it's easy:

1) Get both of your bar nuts
2) Screw them both onto the stud you want to remove
3) Screw them together, tightly (two spanners)
4) Undo the stud by turning on the inner nut
5) Unscrew the nuts (two spanners).
 
A member by the name of Mr Hall (Thallxxxx) posted a lot of pics how to disassemble this partical saw. Do a quick search and you will find what you need, and you don't need the special tool really.
 
I used both of the bar nuts(double nut)together. It came out kind of hard but it did come out. Good luck...
 
I am in the process of rebuilding an MS290 to correct damage caused by ethanol. I have a new engine and have disassembled everything that I need to. All that is left are the four bolts that hold the engine together and to the plastic frame/chassis/crankcase (depending on where you look as to what is called). I removed one OK, one of the ones in the open on the outside. When I went to removed the second one, which is down a square hole (naturally), the head twisted off the socket and is wedged in the bolt. It is one of the torgue (sp?)/star bolts.

It appears to have been over tightened at the factory, and in checking the other two they are also over tightened. The factory specs call for 11 Newtons or 8.3 ft/lbs to tighten and I applied well over 30 ft/lbs trying to loosen then. I know that this saw has never seen a torque wrench as it went down the assembly line, most liked air drills.

So, I have two problems. The first is the broken part of the socket imbedded in the screw. I have managed to drill out part of it, but so far have not been able to clear the remainder. I am getting close to just drilling the head off the bolt so I can pull it through the frame/chassis/crankcase - and then tackle the other two. If anyone has some experience with this problem, I will be most interested.

The second problem I am facing, is if I do wind up having to drill the head off the bolt then I have to remove the bar stud that threads into the engine. I checked with Stihl on the "special tool" that they have to remove it and was quoted a price of $82-$84 for it. With a number of people having rebuilt these, what is the method used to remove the bar stud without having to give Stihl another $84.

Any information and previous experience in these issues will be greatly appreciated. The patience is starting to wear thin with this thing, I am convinced that it was either built on a Friday or Monday - either getting ready for the weekend and not caring or with a hangover from the weekend and caring even less.

Thanks,
Fog

Unfortunately you are going to have to drill the socket head off of the over tightened bolts. I have been into a few MS290's and Stihl MS250's with the same problem. I am really not sure it was over torked at the factory, because it is possible that someone else had been into these saws.
As for removing the engine you will have to remove the bar stud, and the method described above will work fine. I have the Stihl special tool but did not pay as much as you described (perhaps dealer mark up is to be credited for that). I am told you can buy a stud remover and use it just the same, it may flatten the threads a bit, so you can chase them with the proper tap and clean up the threads.​

The thread by THALL is a great thread and can provide the visual's that you may need to make this process easier. Otherwise, there is also a thread by THALL concerning removing bar studs without the special tool. You should be fine, hope you get it up and running soon.
 
I believe his problem is the 4 engine bolts on the bottom of the saw, not the bar stud. I twisted a Wiha T-handle off on one of those. The piece came right out and another T27 got them all out. Perhaps there's loctite on it?
 
I believe his problem is the 4 engine bolts on the bottom of the saw, not the bar stud. I twisted a Wiha T-handle off on one of those. The piece came right out and another T27 got them all out. Perhaps there's loctite on it?

"The first is the broken part of the socket imbedded in the screw. I have managed to drill out part of it, but so far have not been able to clear the remainder. I am getting close to just drilling the head off the bolt so I can pull it through the frame/chassis/crankcase - and then tackle the other two. If anyone has some experience with this problem, I will be most interested."

I have broken off a few Craftsman socket type extensions trying to get these overtightened bolts out. Since you have already drilled into the one you'll have to drill the head off of it. If the other ones are just as tight you may try using the socket head torx and an longer handle ratchet. If you remove the engine entirely the bar stud will have to come out.
 
Ok, I have plenty of "time in grade" on the 1127 series. Lets start at the beginning.

If ever this is important, it is CRITICAL here on the 1127 engine bolts. First you MUST take a pick or whatever and clear out all of the debris in the T-27 screw head. I hit them with a shot of compressed air after that. This will allow the tool to fit in there solidly. Now you need a decent quality T-27 driver. T-25 will strip in these every time. If you cannot find one, your dealer should have a dozen or three Stihl brand "L" wrenches around. These wrenches will loosen the bolts in question, but it can be very hard on the fingers due to the size of the wrench. Those bolts are not overtightened. They have a locking feature on them to prevent them from backing out.

If you do not want to split the engine, you will need to remove the rear bar stud. Thall put a video on here a few weeks ago about getting those out with the bar nuts. I have not had any success at that. They are cheap, and in stock at any decent dealer though. I would suggest splitting the engine any time the four mount bolts have been loosened, but that's your call. It would be very easy to develop an air leak since nothing is holding the bottom pan on once the four bolts are out.
 
Thanks to all for all the information and sharing your experiences. Learning something new is always a good thing. Looks like I will be drilling the head off the bolt tomorrow - can't get the remaining fragments out of the bolt.

I looked at Thall's video on removing the bar stud a couple of times today, had to with all the Elvis and positive attitude. Sure made it look easy, but I know how that goes - its easy when you've done it a number of times. I feel better about now.

I already have my non-EPA muffler ready to go and a genuine Stihl limiting caps puller - so I am anxious to get this thing going again. That and I have several logs to cut up and convert into bowls to sell to pay for the new engine.....

Thanks again,
Fog
 
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