How to repair stripped valve cover bolts - aka using helicoils & timeserts

Discussion in 'Technical Reference' started by Colo moto, Jul 29, 2009.

  1. Colo moto CH Sponsor

    Location:
    La Jara, Colorado
    Husqvarna Motorcycle:
    7602racing.com
    Coffee EDIT - link to discussion thread:
    http://www.cafehusky.com/forums/showthread.php?t=4217
    Also, at some point the pictures disappeared, I will leave this thread in case it is helpful to someone..
    -----------------------------


    While checking my valves the other day I managed to strip out one of the valve cover bolt holes. I know a few others have done this too, so I took pics of the repair, and thought I would do a quick how to on it. So here it goes.

    Step 1: Remove the seat, tank, and valve cover. I didn't take pics of this part because that's all pretty self explanatory.

    Step 2: Locate which bolt hole you have stripped out. There are only 4 and I happened to strip out one of the intake side bolt holes. This was lucky in a way, as I was able to do the repair with the engine in the frame. If you can't get to the stripped bolt hole easily it's best to remove the cam retainer. Pull the two bolts that secure the cam retainer to the engine, remove the cam retainer and repair the stripped bolt hole.

    Step 3: Once you know which bolt hole you are repairing, take a clean rag, or cloth and cover the cylinder head only exposing the hole you are repairing. This prevents any debris from falling down into the valve train.
    [IMG][/IMG]

    Step 4: Open the thread repair kit and make sure you are comfortable with the installation instructions. I chose helicoil because I have used them for several years with good results. Many people prefer to use timesert thread inserts. You will need a kit with 6mm length inserts. A kit should come with the thread inserts, an install tool, and a tap. This is a special tap, so don't try using one you have laying around the garage.
    [IMG][/IMG]

    Step 5: Grease up a 1/4 inch drill bit and drill the stripped hole to the same depth as the existing hole. The grease holds the chips and prevents them from flying around and possibly entering the engine.
    [IMG][/IMG]

    Step 6: Grease up the tap, and tap the hole all the way till your tap bottoms out. Once the hole is tapped, take a Q tip and clean out the hole making sure to get out all the chips the grease might not have trapped.
    [IMG][/IMG]

    Step 7: Take the install tool and install the thread insert. A properly installed insert should be flush with the top of the hole or just slightly below but never sticking above the hole.
    [IMG][/IMG]

    Step 8: With the thread insert installed you are pretty much done. Check one last time for any metal chips that might fall into the engine. Reinstall the valve cover, gas tank, and seat. Go out and jump for joy that you just saved yourself $100 by fixing this yourself.
    [IMG][/IMG]

    I know that is kinda quick and dirty, but this really is a pretty easy fix. If you can change a tire you should be able to do this with no problems.
    sam v likes this.
  2. rajobigguy Administrator

    Location:
    So.Cal.
    RockinRod likes this.