replacing studs, what do I need?

anim8r said:

I'm being as cautious as I can with my 1st build, & popular opinion here says I should replace the mounting studs on my china girl. I'm not mechanic, so a lot of this stuff is really alien to me....try not to bust a gut at my ignorance.

BikeGuyJoe's motor prep thread mentions using M6X1.00 threaded rod for replacing the studs. So I went to Home Depot, & they looked at me like I was trying to order a rare imported cheese. They said it's metric, so they wouldn't carry something like that.

So now I'm wondering if I can find what I need somewhere else, or if maybe there's something else I can use. Do these things run in standard size? Should I be looking for bolts instead? If so, what size?

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I just went through with all of these shenanigans.

They don't have it at home depot. If you google it, it's online, but you do have to pay shipping.

They do, however, have bolts in that size. You won't be able to replace the rear mount studs (far too long), but the others you can. You just cut them to size.

I ended up drilling and threading my bottom mount holes to 5/16. Now it is alot stronger

I ordered mine though Sick Bike Parts they had a couplet set of hardware(didn't cost a fortune ether) They are good folks and do a grate job.

Just go to the hardware store and buy 3" metric bolts and cut the heads off. You should be able to find at least Grade 5 bolts. I replaced all my studs this way. All you need is a hacksaw and maybe a file.

Any threaded rod you find will probably only be about grade 2, or 3. Not really any better than the stock studs

biknut said:

Just go to the hardware store and buy 3" metric bolts and cut the heads off. You should be able to find at least Grade 5 bolts. I replaced all my studs this way. All you need is a hacksaw and maybe a file.

Any threaded rod you find will probably only be about grade 2, or 3. Not really any better than the stock studs

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NOT true.. I buy my metric stock from a fastener supply, they are a Metric 8.8 (USS grade 5). I buy them by the meter and cut to size. Also NAPA carries all thread (metric 8.8) sold by the meter also. A stick of 6mm X 1.0 and 8mm X 1.25 will cost you around $10.00.

anim8r said:

Thanks for all the input. Looks like I'm going with the Sick Bike Parts kit....everything I need to replace the original hardware with grade 5 for $10.

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You sure EVERYTHING ??

Here's what the set comes with:

No head studs, they are sold separately.

Sure. Should not be a problem. Just don't overtighten the stock studs, especially the acorn nuts.

The thing that is most (as I see it) important in installing one of these engines is to make SURE that the engine is mounted correctly. There should be NO gaps between the engine mounts and either tubes. Most of the time the rear engine mount fits, but the front engine mount needs some type of modification. Number one problem is with cheap stock parts mainly the hardware. If the mounts are not correct, or the studs are in a bind, then you may end up with either a broken case, stripped holes or if you are lucky just a stripped stud. MOST of the time the stud will snap at or close to the case hole. The kit that you bought with the mounting studs to me are the most important. Next will be the cylinder studs. That is why I asked if you bought everything, which you didn't.

Pay attention building, don't hurry, and check everything over..not just the engine but everything that will be between your legs going down the road at 30MPH.

Check these photos out to get some ideas.
http://s982.photobucket.com/albums/ae309/Ron-Becker/Engine Mounting/

Here are some other ideas.
These are the things that I do, I see that others such as the seals (which I've never had one go bad) mentioned. All these mods or replacements are most likely less then $50.00. Choose what works for you, ignore the rest, but here you have them.

1. Unpack engine
2. Check for any missing parts
3. Remove head
4. Mill head (flat glass and 230 (or finer) grit sand paper. Rub gasket surface to insure it is flat. Check the cylinder also.
5. Tap cylinder stud holes to insure they are taped to the bottom.
6. Discard all studs and nuts.
7. Replace studs with Metric 8.8 (US Grade 5) Replace nuts with locking nuts. 8mm studs are either 1.0 or 1.25 thread, 6mm studs are 1.0 thread. 8mmX1.0 is not common, but I have 1 engine with them.
8. Replace spark plug with a NGK or the like.
9. Replace spark plug wire and boot (check with lawnmower supply) or rob from old lawnmower. Use wire core lead.
10. Mount the engine properly, no gaps between the bike tubes and engine mounts.
http://s982.photobucket.com/albums/ae309/Ron-Becker/Engine Mounting/
11. Torque 8mm to 150 to 200 INCH POUNDS
12. Torque 6mm to 60-70 INCH POUNDS
13. I install cylinder studs with lock tite, and let set overnight
14. I coat the head gasket with Copper Kote
15. May need to bend exhaust pipe for crank or frame clearance. Recommend using heat.
16. Remove or cap magneto white wire off.
17. Re solder blue wire on magneto.
18. Make sure all wires have a good connection and use tape or better yet heat shrink.
19. Hook up kill wires AFTER you get engine running.
20. Try not to drill holes in the bike frame.
21. Do away with the clutch cable routing; there are a number of options.
http://s982.photobucket.com/albums/ae309/Ron-Becker/Homemade Mods/
If you want to make yourself, PM me and I’ll give you a material list.
22. On my kit the rag joint had gauge (Metric) 8.8 bolts, If not replace them. I replaced the nuts with lock nuts.
23. I sealed the wires coming from the magneto out of the engine with RTV.
24. Place a “O” ring in the carburetor throat.
25. Some say replace the axle with a better one. Never had a axle bend on me.
26. Use thin wire (I use Stainless safety wire).and wrap around the idle screw and secure to the carburetor.
http://s982.photobucket.com/albums/ae309/Ron-Becker/Homemade Mods/?action=view&current=MVC-003F.jpg
27. For coaster brakes…Some say trim the cap, but I don't like it.
http://www.youtube.com/watch?v=M3IPgvZLccI or a file of sorts can be used.

Great tutorial, Alf !
Wow!

A little bit of fine tuning and it should be a sticky...

That bolt kit pictured is a bargain for $10 !
I've spent more than that at the LHS and I'm not done yet.

Best
rc

I got a wet spot at top of cylinder now, front of engine where it meets the head... got the acorns on the head, too. SO, I guess that's one of the next things to deal with.

rustycase said:

Great tutorial, Alf !
Wow!

A little bit of fine tuning and it should be a sticky...

That bolt kit pictured is a bargain for $10 !
I've spent more than that at the LHS and I'm not done yet.

Best
rc

I got a wet spot at top of cylinder now, front of engine where it meets the head... got the acorns on the head, too. SO, I guess that's one of the next things to deal with.

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Thanks...but hardly anyone reads stickies...that is why we have to repeat answers to questions over and over, real simple questions.

The picture of the bolt kit isn't bad at all. Important items are the studs/nuts.

anim8r said:

Dude, that's a serious list. Thanks for all the info. I understand most of it, but I have some questions about some parts. I don't wanna trap you here, so if anybody else wants to tackle any of these questions feel free to jump in:

steps 3 & 4. what's the deal with removing & sanding the head?
Using 230+ grit sandpaper and a sheet of glass..work the surface till the surface is flat.
5. How can I tell if the cylinder stud holes are tapped all the way to the bottom?
Use a bottom tap and make sure its taped to the bottom.
11 & 12. how can I measure the amount of torque? (I'm guessing some kind of special wrench..?)
Using a 1/4" drive inch torque wrench.
16. what's the deal with that white wire?
Used for a light...just remove it.
19. why AFTER?
If the engine doesn't start, you know it's not a defective switch.
21. what's the deal with the clutch cable routing?
Most people have to pull the clutch real hard, this is because of the routing among other things.
22. Lock nuts!! good idea.
Much better then factory, and better then regular.
24. I'm just completely ignorant here...which part is the throat, & why does it need an O ring?
Where the manifold goes into the carburetor.

Other than that, it feels like I'm on the right track. I've got a standard Schwinn cruiser, so there shouldn't be any drilling. I'm taking care of the wheels & hubs this weekend to make sure they're ready for some abuse. I just rebuilt the bike for the sake of "getting to know it better" & making sure all the parts are doing their best. My biggest problem right now is waiting for those replacement bolts to be delivered...

Again, great list & thanks for taking the time to put it together. Got my vote for a sticky, as well.

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Most likely you will need a after market front mount, dealing with a cruiser.

Have you read the stickies...be honest.

anim8r said:

Yep. Well, ok...I've read some of the stickies. Mostly the ones pertaining to my current steps & next steps. Generally I use the search function here to get the info I'm looking for. If what I find turns out to be too technical or assumes I'm a more competent mechanic than I actually am, I'll post a question.
There should be a folder of just stickies called "First build? Read these or suffer the consequences." Maybe some of the elites & old timers could vote on some of the best.

Back to the head sanding.....what does it do for the motor?

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First and foremost it ensures that the head is in fact flat. Like milling a head on your car. Second since the heads are warped from the factory, and are prone to leak or blow out a head gasket..this corrects that. The more you take off the head/cylinder the more compression it will have...good up to a certain point. I didn't want the extra compression so I put 2 head gaskets on.