manks7477

I have an OS 91 FS Surpass engine, it has been stored for a long time and seems to have gummed up a bit, I need to get inside it. One of the Hex Bolts on the top of the engine has stripped, any thoughts on how I can get it out so I can degum the inside of the motor?

Villa

First, spray some release agent on the bolt threads. Then use a Dremel tool with a cut-off wheel on it and grind a groove on top of the bolt so you can use a flat screw driver to back out the bolt. The cut-off wheel must the thin type.

manks7477

That is pretty much what I was thinking. I already sprayed the bolts with WD 40, should I try something else as well?

SrTelemaster150

Heating it up in the oven (when wifey's not home) will help.

Craftsman makes extracting tools that will grip the stripped out head & back the screws out.

http://www.craftsman.com/craftsman-3...p-00952154000P

They are handy to have around the shop. I've used mine quite a few times.

manks7477

I will be buying one of those tomorrow!

jester_s1

An easy method to try if you're fairly sure you've gotten the penetrating oil to the threads (Kroil is the best I know of, with Liquid Wrench an old standby as well) is to clean it with acetone and then CA glue the allen wrench into the screw head. Obviously, that won't let you torque it out if it's still stuck, but it will help if you're just needing a little bit more grip that what you have.

gene6029

Another way to apply heat to the bolt is with a soldering iron held on the bolt head. It applies the heat directly where you need it. An easy out with the tip ground flat to fit inside the bolt head will allmost definately break it loose......Good luck...Gene

AMA 74894

My Feedback: (1)

great tips!! one more to add, along the lines of what jester mentioned for removing screws (flat, phillips or hex) that you need to get just a little more 'grip' on:
put a tiny dab of valve grinding compound in the screw head or on the tip of the screwdriver / bit.
it allows just a little more ''grip" .. and of course is way easier than drilling / easy-outs / etc.
learned that one three decades ago, I ALWAYS have a tube of valve grinding compound in my toolbox now
hope that helps someone!

bikerbc

If all else fails and you cant remove it you can use a drill and drill the top off it off just enough so that you remove the bolts head and then when you get the top off the motor there should be enough of the bolt left to grab with the vice grips to remove it .

opjose

Yup, this works well. I've done the same thing.

Better still heat the engine body ( not the bolt itself, as this causes it to expand ), then grab the exposed area with the grips and turn slowly to back it out.

If all else fails, you can also use a "center drill" to start a hole into the existing bolt, the follow up with a slightly oversized drill bit. Once you've removed the old material, tap out a new slightly larger thread and use a new corresponding bolt.

Gray Beard

My Feedback: (-1)

All of the above but I have never tried Jims little trick. I have some tapered grinding tips that will remove the head of the screw as Ken mentioned instead of a drill bit. When I assemble an engine I use never seize on all the screws. Most people will tell you to use lock tite but even with the never seize I have never had any screws back out from vibration. For cutting a slot for a screw driver I use my dental hand piece with some very fine wheels but sometimes even those can't get into the area of the head to slot the tops. I use boiling water to heat the engines but the oven works just fine too. I have had to boil them then stick them in the freezer several times to get the screws out. The heat and shrink will loosen them up.

manks7477

I went the route of buying the tool. Took less then a minute to get it out.

Now comes the hard part. I have the valve cover open and have sprayed brake cleaner on the valves, when I turn the prop there is still no compression, the valves are not moving. Any thoughts here boys?

SrTelemaster150

Those extractors will come in handy a lot!

SrTelemaster150

The valves are hanging open. Remove the rocker arms if you can. Then you can remove the valve spring & clean the valve stems so you can push them out. MARK THE VALVE IN/EX. Try not to mix them up.

Clean the valves & use a pencil eraser to clean the valve seats. If that doesnt get them clean, get some paint rubbing compound & use the valves to polish the seats.

While you're @ it have a look @ the bottom end for rusty bearings.

SeaJay

My Feedback: (6)

In the past, I have used a small sauce pan, put the engine in the pot, covered it with rubbing alcohol, heated the pot on medium low on my electric stove (don't think I would try it with a gas stove, after the engine is warm, about 125 - 150 deg. push down on the valve push rods to loosen up the gunk in the engine.. you will probably have to work the engine and valves a bit, but the combo of rather low heat and alcohol usually clears all that gunk out.. I have used this method on a stuck YS FZ 140, worked well..

Craig.

Gray Beard

My Feedback: (-1)

If it's that gunked up it's easier to just strip down the engine and clean it completely. Sounds like the lifters are stuck inside the the case. Clean out the push rod tubes too while they are off. Removing the valves can cause a lot of swearing when you try to get them back in. If the valves aren't really stuck leave them alone.

manks7477

Going to try soaking it in fuel overnight and see if that helps. Hobby shop idea - maybe they just wanted me to buy more fuel!

moto-x

Remove the carb and glow plug.Put engine in a pan of antifreeze .Deep enough to emerge entire engine and heat to almost a boil for awhile.It will loosen all up and look like brand new.

dbsonic

My Feedback: (3)

extractor or ez-out is the way to go, unless of course you break the ez-out trying to get the bolt out. Then you are really hosed.
btw, the anti-freeze trick only works for glow engines(does nothing for carbon build-up on gassers). But should work here.

moto-x

The OP stated it is a glow engine. I have been a tool maker a long time, I know how to remove broken bolts. I"m just trying to give another option on cleaning the engine without pulling it all apart.

manks7477

I "cooked" the engine in anti-freeze at about 150 F for 2 hours. Took it out, turned the crank a few times and it freed right up. Compression is back, I oiled it and will mount on my test bench tonight and run a tank of fuel through it. The best part is it looks like a brand new engine.

I liked the Anti-Freeze bath so much I put my OS 46 FX in it right after. I will be cleaning up all of my engines in the next few days

moto-x

Glad to help. Been doing that since the 70s on motorcycle carbs. Just about anything aluminum that has had fuel. And no, It won"t remove carbon but it will loosen it up to scrub off easier.

manks7477

I have three engines taking a bath right now! I did the 4 stroke and then an old OS 46 FX - both look like they just came out of the box new! Oiled them up and there is tons of compression, everything is smooth - perfect!

I have a couple of really old ones in the bath now, maybe 40 yr old OS MAX 25 and an slightly younger OS 46 SF. Will let them sit and stew overnight and see how they come out.

rlipsett

just remember don't dunk the carb. the antifreeze will deteriorate the rubber o rings

manks7477

Thanks for the reminder, For most of them I took the carbs off, for a couple, I could not get them off for one reason or another, so I put them in and took the chance. These were all very old motors that needed it so the risk was worth while. I will take them to my LHS and get some help getting the carbs off, then replace the o-rings. Should be ok.

For the good engines I was VERY CAREFUL!