Hey everybody,
A while back I had a bore job done. The guys who did it went out of business. This week I blew a head gasket. When I took it apart I found two of the cylinder studs are
pulling out of the crank case. What'sthe cure for this and how is it done. It's a 1992 EVO.

Thanks in advance, Easy

 

HeliCoil inserts are stronger than the original. Some manufacturers of various items use them as oem in aluminum for various things for that reason.

I'm not a bike mechanic and I don't know if they work on your block but I can't imagine why not.

 

Thanks, J
HeliCoils were one of my thoughts, but a shop told me I had to take the engine out and split the cases before I could drill. I was hoping not to do that as it's only one cyl/ two studs.

 

i had the same problem, leaking head gasket and found out the front stud had pulled out of the case. put a heli-coil in and solved the problem, the mech. said the heli-coil was 10 times stronger than it was before, have you ever tried to pull a heli-coil out, next to impossible. if i ever tore my engine all the way down id heli-coil all the case holes then sleep tight.

 

You shouldn't have any problem drilling in frame. You do need to be real carefull not to get chips anywhere in or near the crank, cover the piston and crank cavity well and use some grease on the drill and tap to hold chips, drill slow and let up several times to break the chip as it comes out. Take it carefully and you'll be OK.

 

I had the same problem. I heli-coiled but a month later a different stud stripped in the crankcase. Unless you do all the studs, this might happen to you also. Probably what happened was that the mechanic took out the studs. Big no-no. Never touch those damn studs unless you have too. Once you mess with them, you are looking for problems.

Drilling and putting the heli coils in straight is a problem too. Use a fixture or you will drill crooked. Use pipe cleaners to plug the bottom of the hole so nothing gets into the crankcase.

 

In my experience with Helicoils, you only need to remove a small amount of material with the drill. I've done it by hand with a sharp bit in an aluminum head. You really are only removing the last of the original threads. The critical part is getting the tap in straight. That's where some type of guide would be handy.

 

Hot Rod, DeJavu, Blueglide & Dr. Hess,

Thanks for the suggestions. I think I'm going with the helicoil with the engine still bolted in. I put some thought into it and I'm going to run an allen set screw
down on the few remaing threads so the filings don't go into the case. I'll let you guys know how it goes.

Thanks again, Joe

 

How do you plan on getting the set screw out? If you are using it just to keep chips out of the crankcase when drilling, there will be no more threads left for which you need to unscrew out the set screw because you just drilled out the threads.

If you are going to use it to also keep out the tap debris, then again the threads are not the same and you cannot back out the set screw. You do not want to leave that set screw in there.

Try the grease and the pipe cleaners. Clean out the hole with an air blast very often and you'll be ok. The set screw sounds dangerous to me.

 

Blueglide88,

My thought was this. The stud does not go all the way down through the case, but the treads do. When the stud pulled out it left about 1/4" of threads.
So I did it. I put a set screw down and it treaded into the remaining threads. I drilled to the set screw, then cleaned completly. I then tapped the larger hole for the helicoil and again
cleaned completly. I dipped the allen wrench in oil, unscrewed until it was to the larger threads. The suction from the oil kept the wrench on set screw and it sliped passed the
larger threads. No shavings in the case and with my fingers still crossed I've put 200 miles on her so far.

Easy