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Login to post Forums » Sprockets » Motorcycle carburetors should not be held together with Philips head screws.

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Feb. 16, 2011 9:50 a.m. MadScientistMatt Dork

That is all.

Ok, maybe not, just had a mini-rant as I was trying to take the float bowls off my GS500F to clean out some clogged jets. The Philips head screws were frozen solid. Ended up getting six of the ten I need to remove out with a Pozidrive, three of them ended up boogered up beyond repair, and one's stuck behind two of the three boogered up ones. I'll try some PB Blaster instead of the WD-40 I had on hand, and either use Vice Grips or cut some slots in the heads to get them out, then replace them with Allen head bolts.

Surprised how many of my fellow engineers apparently don't realize the point of Philips head screws is to prevent people from applying serious torque to a screw.
Feb. 16, 2011 9:52 a.m. ClemSparks SuperDork

I really woudn't care if I never had to use another philips-head screw ever. They're so darn common, though, that they're hard to avoid.
Feb. 16, 2011 10:03 a.m. Grtechguy SuperDork

I like square / torx drives
Feb. 16, 2011 10:24 a.m. ransom New Reader

And that's just the pain inflicted on the GRM crowd which recognizes different sizes, the quality of screwdrivers, and the distinction between Philips and Reed & Prince.

How does the rest of the world ever (dis-)assemble anything?
Feb. 16, 2011 10:30 a.m. Ranger50 HalfDork

I thought the whole point to a motorcycle was to never take it apart, as evidenced by the way they are assembled.

I hate Torx. No sooner do I have a new bit, it's either rounded off, twisted, or broke. Doesn't even matter on the size, except for the T20 bit for my lil 7.2V cordless SnapOn screwdriver.
Feb. 16, 2011 10:39 a.m. triumph5 Dork

ransom wrote:

And that's just the pain inflicted on the GRM crowd which recognizes different sizes, the quality of screwdrivers, and the distinction between Philips and Reed & Prince.

How does the rest of the world ever (dis-)assemble anything?

Call the repairman, or throw it away.
Feb. 16, 2011 11:00 a.m. tuna55 Dork

MadScientistMatt wrote:

Surprised how many of my fellow engineers apparently don't realize the point of Philips head screws is to prevent people from applying serious torque to a screw.

Engineer here - I agree.
Feb. 16, 2011 11:12 a.m. 1988RedT2 Dork

I did in fact, within the last 12 months, replace the phillips head screws on my carb float bowls to allen head screws.
Feb. 16, 2011 11:21 a.m. 44Dwarf Dork

Your just not using the right tool! Philips are just fine! but i admit i like allens best. Never try to remove a screw with out the use of a hand held impact driver. like these http://cvfsupplyco-store.stores.yahoo.net/imdrhaheimdr.html

Get the extended bits too for float bowls you'll never have a problem again. Don't have to wack it hard either.

44
Feb. 16, 2011 12:33 p.m. foxtrapper SuperDork

When it comes to motorcycles, the hand held impact driver is always the necessary screwdriver. From carburetor bowls to case covers, it's the go-to tool.
Feb. 16, 2011 1:35 p.m. tuna55 Dork

1988RedT2 wrote:

I did in fact, within the last 12 months, replace the phillips head screws on my carb float bowls to allen head screws.

Again, engineer, here: Most allen bolts are intended for indoor use due to their not being graded the same way as others, and typically being much harder. Sounds great, but the facts are that harder bolts can't be coated the same way without getting into hydrogen embrittlement and such, therefore they typically rust pretty badly unless you found a special allen headed grade 8. I prefer torx for both inner and outer if I can find them, but I can't.
Feb. 16, 2011 1:39 p.m. MadScientistMatt Dork

I'll be using stainless Allen head bolts on my carbs - I used some off the shelf black coated ones for some homemade bar risers, and they rusted.
Feb. 16, 2011 1:57 p.m. JohnGalt Reader

Not the biggest fan of Phillip head screws my self and they are very terrified of me. Most of the time all i have to do is pick up a screwdriver and they begin to weep, lament, and deform.
Feb. 16, 2011 2:54 p.m. tuna55 Dork

MadScientistMatt wrote:

I'll be using stainless Allen head bolts on my carbs - I used some off the shelf black coated ones for some homemade bar risers, and they rusted.

Careful with stainless, that stuff is surprisingly weak - you might lose some important clamping load with locations designed for a high grade steel fastener since you have to back the torque down so much.
Feb. 16, 2011 7:13 p.m. Curmudgeon SuperDork

My last Honda and my Yamaha were put together with 6mm thread bolts with 8mm flanged hex heads, such a wonderful idea. In the dim dark past someone went through my XS650 with Allens, I'm so happy I could weep.

Again, if I ever meet that guy Phillips he's going to leave bruised and bloody. Dammit.
Feb. 16, 2011 7:32 p.m. 1988RedT2 Dork

tuna55 wrote:

1988RedT2 wrote:

I did in fact, within the last 12 months, replace the phillips head screws on my carb float bowls to allen head screws.

Again, engineer, here: Most allen bolts are intended for indoor use due to their not being graded the same way as others, and typically being much harder. Sounds great, but the facts are that harder bolts can't be coated the same way without getting into hydrogen embrittlement and such, therefore they typically rust pretty badly unless you found a special allen headed grade 8. I prefer torx for both inner and outer if I can find them, but I can't.

This bike is garaged and won't see weather. If I find them rusting after a year or two, I can replace them. I honestly don't remember for sure what finish they had, or even if they were stainless, although I doubt it.
Feb. 16, 2011 11:50 p.m. alex SuperDork

Former pro vintage bike mechanic here. Snap-On* handheld impact driver: I don't look at old phillips hardware without it in my hand.

*Yes, there is a difference. All of Snap-On's phillips drivers bite and set in a way no others do. This is not a paid endorsement, just the voice of my own experience. Your mileage may vary, see dealer for details.
Feb. 17, 2011 9:15 a.m. MadScientistMatt Dork

tuna55 wrote:

Careful with stainless, that stuff is surprisingly weak - you might lose some important clamping load with locations designed for a high grade steel fastener since you have to back the torque down so much.

If they designed something to need a high clamping force and specced out Philips head bolts, they're even bigger idiots than speccing them for something that rusts together easily. But you're right that those would not be appropriate for some other items.
Feb. 17, 2011 9:40 a.m. tuna55 Dork

MadScientistMatt wrote:

tuna55 wrote:

Careful with stainless, that stuff is surprisingly weak - you might lose some important clamping load with locations designed for a high grade steel fastener since you have to back the torque down so much.

If they designed something to need a high clamping force and specced out Philips head bolts, they're even bigger idiots than speccing them for something that rusts together easily. But you're right that those would not be appropriate for some other items.

Good point, I lost sight of the original replacement for Philips and just focused on replacing steel with SS.
Feb. 17, 2011 4:12 p.m. Toolpen New Reader

Working as a motorcycle mechanic, I have to agree with the Snap-On impact driver as I've been using mine for over twenty years. When working with Phillips screws, I also fill the recess in the screw head with valve grinding compound to help the driver bit bite harder and reduce camout. You can also find screwdrivers with ACR (anti-camout) ribs in the tips to help improve the tools bite. Removing/tightening these screws can be interesting.
Feb. 17, 2011 10:30 p.m. Trans_Maro Dork

I've owned plenty, snap-on makes the best phillips screwdrivers, bar none.

Shawn
Feb. 20, 2011 9:45 p.m. porksboy SuperDork

I know it sounds counter intuitive but put loctite on the threads of your carb screws. It helps prevent the corrosion you see on the theads when you finally get the screw out. That is what had it stuck so tight in the first place. Steel screw into an aluminium threaded hole will do that.
Feb. 21, 2011 1:58 p.m. dculberson Reader

What about anti-seize?
Feb. 22, 2011 12:39 p.m. 93gsxturbo HalfDork

MadScientistMatt wrote:

That is all.

Ok, maybe not, just had a mini-rant as I was trying to take the float bowls off my GS500F to clean out some clogged jets. The Philips head screws were frozen solid. Ended up getting six of the ten I need to remove out with a Pozidrive, three of them ended up boogered up beyond repair, and one's stuck behind two of the three boogered up ones. I'll try some PB Blaster instead of the WD-40 I had on hand, and either use Vice Grips or cut some slots in the heads to get them out, then replace them with Allen head bolts.

Surprised how many of my fellow engineers apparently don't realize the point of Philips head screws is to prevent people from applying serious torque to a screw.

Thats because they may not be Phillips screws but are JIS screws.
http://www.instructables.com/id/When-a-Phillips-is-not-a-Phillips/step10/JIS-Japan...

Look at the head of the screw for a small dot/dimple in one of the quadrants and use the right tool for the job. It will make your life much easier.
Feb. 22, 2011 1:05 p.m. subrew Reader

Considering that most of the phillips head use on a carb are for connections using a gasket (float bowls for example) phillips are just fine. Joey Overtorque need not apply.

If you are replacing with allen head so you can torque them more, then you are just putting on a band aid.

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