Intake boot removel help

[Roostabunny]

Hard to believe

Can't help an more than previous posts on the broken screws, I've got a strange experience with getting those screws loosened on my bike.

I had a mechanic friend helping me the first time I pulled the carb boots off my GS850 hunting down my intake leak. After we struggled with the same problem of not enough space to swing a hammer at the impact driver he tried a trick that made me really nervous but worked.

He took a chisel punch, aligned it on the edge of the screw head from the side, and struck it so that he actually got the screw turning. Kind of a glancing blow.

Now this guys been a bike mechanic for well over 20 years, so he probably had a back-up plan. But to my amazement not only did it work, but the chisel damage to the screw heads was minimal. Since I was planning to have the carbs off again in a week (couldn't find the right size o-rings that night) I just put them back in. Then I planned my route home the next day to go by both NAPA (for the o-rings) and Ace (for hex head replacements).

I guess I can't really recommend this method in general, but having seen it work and having a vague idea of the physics that made it work, I'd try it again myself as long as I was comfortable with my, uh, Plan C. Either way, in the interest of adding to the general knowledge, there it is.

[TheCafeKid]

That's my way of thinking too. Aluminum expands faster than the steel screw.

I remember something about this in chemistry class....and if i remember right heating the aluminium isnt going to work because its not just going to expand outward....the hole will expand inward...we heated a steele donut more or less and the question was with the donut hole get bigger, get smaller or stay the same diameter...and...i cant remember...but it stands to reason it would get smaller cos its all expanding...does that make sense?

[spyug]

Roost, it is interesting that you mention that trick as I have seen my pro wrench do that as well. I had a set of carbs on my old Virago that had one screw in the float bowl that the screw driver slot was buggered by the PO. I couldn't see how to buge it but the wrench did exactly as you described and out it came.

Now I was trying to get my intake boots off but couldn't budge any of the screws so gave up as I was afraid I'd end up as most do with the screw head busted off. I forgot about this little trick. I should give it a try.

Good piece of information.

Cheers,
Spyug.

[Roostabunny]

Then I planned my route home the next day to go by both NAPA (for the o-rings) and Ace (for hex head replacements).

As an aside, further reading on the topic of carb boot o-rings has led me to believe that the standard o-rings I got at NAPA might not last. Since I also bought non-stainless hex-heads (to save a few bucks, I guess) I'm just going to get the whole ring/stainless kit from our friend at Cycleorings.com.

[themess]

Standard O-rings from NAPA would probably be made of nitrile rubber, which definitely can't take the heat from the heads. Get O-rings from Robert Barr, from McMaster-Carr, from Bike Bandit, Alpha Sports, or your local Suzuki dealer.

The original Phillips head screws for the intake boots are steel. When steel and aluminum touch, galvanic corrosion results. There won't be much of a chemical bond between the two metals - iron and aluminum just don't interact easily in this way. But corroded metal acts as an abrasive, resisting turning, and increasing the torque required to remove the bolt. The torque can easily get high enough to break the bolt or strip the head. Stainless steel fasteners don't corrode nearly as quickly as aluminum, and I think (but I'm not sure) that the galvanic corrosion of the aluminum won't be as fast, either. Anti-sieze compound can be used to lessen galvanic corrosion.

Aluminum expands more than steel when it gets hot. How much more it expands depends on the exact alloys used.

The indented paragraph is me dreaming about what happens. I might just be full of sh!t here.

If a metal donut is heated uniformly, all dimensions will increase, including the diameter of the hole. If the entire engine is heated slowly and uniformly, the ID of the threaded hole in the block will grow in diameter. But that isn't what matters. The outer diameter of the bolt threads isn't where the contact occurs between the bolt and the threaded hole. The contact comes on the flat surfaces of the threads. When a bolt is tightened, it stretches. When everything is made properly and is new, the bolt stretches somewhat uniformly, and becomes a linear spring. The flat parts of the threads press tightly against each other, and microscopic surface imperfections generate friction that adds to the torque from the stretching bolt. As the aluminum gets hotter, the separtion between the threads should increase faster than the separation between the steel threads, and the resistance to unscrewing the bolt should increase, which would be the opposite of what is experiences when two steel fasteners are heated.

[egent]

Update #3

I have been soaking the two broken screws for two days with Deep Creep, and for the last 24 hours with PB Blaster. All of this seems to have been making no effect. I tried to see about getting a grip on the screws and turning a little bit today, but they still seem to be stuck solid. All I seem to be doing is chipping away at the little bit of screw sticking out. I would use heat, but the only torch I have is a butane lighter torch, and I don't know if that will generate enough heat to make a difference. I am beginning to think that drilling will be my only option. Is there anyone in the Philadelphia area that is good at drilling out bolts that might be able to help?

Thanks for any and all help previous and future.

[TheCafeKid]

I have been soaking the two broken screws for two days with Deep Creep, and for the last 24 hours with PB Blaster. All of this seems to have been making no effect. I tried to see about getting a grip on the screws and turning a little bit today, but they still seem to be stuck solid. All I seem to be doing is chipping away at the little bit of screw sticking out. I would use heat, but the only torch I have is a butane lighter torch, and I don't know if that will generate enough heat to make a difference. I am beginning to think that drilling will be my only option. Is there anyone in the Philadelphia area that is good at drilling out bolts that might be able to help?

Thanks for any and all help previous and future.

Theres a couple of these threads going, so excuse me if im wrong but didnt you say you had a dremmel? If so i still say you try cutting a slot for a flathead screwdriver and give it whirl. Make sure its a sturdy driver and fits the slot well, and give a couple of good smacks with a hammer...from what it sounds like at worst you're going to have to have them drilled anyway.

[egent]

Yes, you have the right thread, I do have a dremmel with the flexable extention. However, as you can see in the pictures above I don't know if I have enough bolt sticking out to do that, but I just might have to give it a try.

I do wish I was as lucky as you are TheCafeKid to have near by GSRs willing to help you out when you need it.

[TheCafeKid]

why i think there are a couple of GSRs in the PA area... and yes i do thank all of them very much for helping me with my bike...Just keep at it bro and dont get too down, you'll get it licked. You know any mechanics at all?? this is a fairly common problem, for all vehicles, and i bet one could get you squared away sharpish. That lil butane lighter should be plenty hot to get some heat goin in there by the way. Heat the screw, not the manifold. Blue flame is blue flame.

[salty_monk]

Someone mentioned Kroil on here the other day... I'm going to get some & blast mine with that. Pretty sure have already been switched to allen head

http://www.midwayusa.com/eproductpage.exe/showproduct?saleitemid=137203

They do a spray too.

Dan

[chef1366]

Go to your local hardware store and get a torch. You'll get them out. As stated earlier heat around the bolt and tighten it a tad and back it out. Work it back and forth and keep applying the PB.
If you can get a notch in it with a dremmel I would go that route.

[salty_monk]

Cheaper at source....

http://www.kanolabs.com/

I got a free sample of their degreaser too.

[themess]

I am beginning to think that drilling will be my only option. Is there anyone in the Philadelphia area that is good at drilling out bolts that might be able to help?

I've only had to drill out one bolt in my life. I took a long time to do it, and it worked out. My advice, based on just one experience:

> Don't break off so much that you have nothing left to grab. You still need to be able to grab the bolt after it's drilled.

> Get several brand new, high quality bits. Sharp bits cut easier, and heat up less. There are two tip angles, the sharper point cuts a bit better.

> Mark the exact center of the stub with a center punch so that the smallest bit doesn't wander.

> Find a position in which you can comfortably hold the drill so that it aims directly down the bolt. This might require some support. Cobble something together.

> Start with a 1/16" bit. Run the drill slowly, several hundred RPM. Pull the bit out often, make sure that it isn't hot, and lubricate it. Special cutting oils are available, but I think that light weight motor oil will also work.

> You don't want to drill so deep that you start drilling the cylinder head. Using one of your good bolts, measure how deep the bolt goes into the cylinder head when it holds the boot. Mark your bit so that you don't go deeper than the bottom of the broken bolt.

> After the pilot hole is drilled, the rest is relatively easy. Go through the hole with successively larger bits, adding 1/16" diameter each time. Again, don't let the bit overheat, and use oil.

> At some point, the hollow bolt just won't grab the cylinder head threads any more. The heating and cooling from being drilled, and the pressure and torque of drilling will break it loose. Use the stub at the surface to twist it out.

> Clean up the threads in the head with a tap the same diameter and thead pitch of the bolt.

> Use brake cleaner through a plastic tube to blast the oil and metal shavings out of the hole.

> Use new bolts with Allen heads and install using anti-seize compound when you install the new boots.

I'd really appreciate some criticism of these suggestions, from people who have more experience at drilling bolts.

[Nessism]

I've only had to drill out one bolt in my life. I took a long time to do it, and it worked out. My advice, based on just one experience:

> Don't break off so much that you have nothing left to grab. You still need to be able to grab the bolt after it's drilled.

> Get several brand new, high quality bits. Sharp bits cut easier, and heat up less. There are two tip angles, the sharper point cuts a bit better.

> Mark the exact center of the stub with a center punch so that the smallest bit doesn't wander.

> Find a position in which you can comfortably hold the drill so that it aims directly down the bolt. This might require some support. Cobble something together.

> Start with a 1/16" bit. Run the drill slowly, several hundred RPM. Pull the bit out often, make sure that it isn't hot, and lubricate it. Special cutting oils are available, but I think that light weight motor oil will also work.

> You don't want to drill so deep that you start drilling the cylinder head. Using one of your good bolts, measure how deep the bolt goes into the cylinder head when it holds the boot. Mark your bit so that you don't go deeper than the bottom of the broken bolt.

> After the pilot hole is drilled, the rest is relatively easy. Go through the hole with successively larger bits, adding 1/16" diameter each time. Again, don't let the bit overheat, and use oil.

> At some point, the hollow bolt just won't grab the cylinder head threads any more. The heating and cooling from being drilled, and the pressure and torque of drilling will break it loose. Use the stub at the surface to twist it out.

> Clean up the threads in the head with a tap the same diameter and thead pitch of the bolt.

> Use brake cleaner through a plastic tube to blast the oil and metal shavings out of the hole.

> Use new bolts with Allen heads and install using anti-seize compound when you install the new boots.

I'd really appreciate some criticism of these suggestions, from people who have more experience at drilling bolts.

Good advice here.

My comments are to dress the end of the bolt square so it will be easier to hit the dead center with the first bit. A dremmel will not work for drilling since they turn too fast; use a slow turning drill.

Regarding the engine in question, the ideal with the dremmel is to take a cut off wheel and cut a crosswise slot in the screw head so you can get a slot screwdriver bit on the screw. Use your impact driver if there is room.

Good luck.

[egent]

Good advice here.

My comments are to dress the end of the bolt square so it will be easier to hit the dead center with the first bit. A dremmel will not work for drilling since they turn too fast; use a slow turning drill.

Regarding the engine in question, the ideal with the dremmel is to take a cut off wheel and cut a crosswise slot in the screw head so you can get a slot screwdriver bit on the screw. Use your impact driver if there is room.

Good luck.

If I have a dremel that has the slid switch to adjust speed, is it still going to be too fast on the lowest setting? I was thinking the dremel because it is smaller and therefor easier to control. With the flexible shaft it is the same as holding a pencil.

One of the screw heads broke off trying to use the impact driver to remove it. This is why I am reluctant to try cutting a slot as the impact driver broke it once already. If I go to cut the slot, will it damage to intake seal if it cuts across the surface of the head opening, not toward the o-ring but the short sides of the surface? As shown by the blue line in the below picture.



Please excuse my inability to draw a straight line in Microsoft Paint.