The Hodaka Club Forum

Dunn111987 wrote:I know this probly sounds crazy, but would it be possible to add more threads to a new stud? Just trying to think of ideas for a temporary fix for now.

I would think you can't add threads because I think the cylinder stud threads are rolled, not cut. But you can certainly try. If the stud shaft is smaller in diameter than the threads, the threads were rolled. But changing the stud shouldn't be necessary. They have been working for a long time. If for some reason you have one that's a bit too long, use an extra washer under the head nut. If it didn't seat fully into the case, there is a reason which should be remedied. If one is noticibly longer than the others, it isn't the right stud.

If the stud won't hold torque, find out why. Stripped case?

I think it has to be stripped. Just turns now. Not grabbing anything.

That's a bummer Dunn. Case repair required.

Ed
PS: The stud threads are cut - not rolled.

So would a helicoil work alright for this repair? And still chase the other threads with a tap?

Where are you located roughly in Washington? I only for one don't think you have enough metal in that area to do the helicoil but that could only be me. Which case is it, the clutch side is right and the magneto side is left?. ---------Clarence

It's the front hole on the right hand case. I am in the Columbia River Gorge across from Hood River, Oregon.

It has to be said that the normal torque is not the maximum that a fastener will be subject to, as the motor warms and the metals expand, pressures will rise. Goes for cylinder studs as well as the case screws. That's why retorqueing some fasteners is recommended.

Photo courtesy of Bullfrog:

Thanks for posting that, Paul. I was looking thru my own Hodaka photos for an example but couldn't find one.

Unless he has experience with installing helicoils, he might consider farming this helicoil job out. This cylinder stud has to be drilled and tapped perfectly square or the cylinder/head may not fit. And this right front stud can have a connection to the crankcase-- I had a pressure test leak there and had to use sealant on that stud. It's not a hard repair, there is too much risk of ruining the case if things go south.

Should I just try to get another case? I'm not sure how I would go about having someone else do the repair. And that repair in itself may cost more than finding a decent used case and putting new studs in it

I'm a little intimidated by tearing into the engine, but I'm sure I can do it. And it's how I would learn such a thing. Probly a good idea to get a rebuild package with bearings and gaskets and seals? Not be cheap and just redo it while I have it open. I found another case half with studs still in tact. So I will clean it and put new stuff in it, but not mess with those studs! Lol

Sounds like you found your best option! Good luck from here! I hope the rest of the build is worry free!!! Victor

Man I have been so close for monthes to finishing Victor! Just little things keep hampering, but I can't give up now! I'm kind of a perfectionist, so I get fussy! Got another bike to redo this winter also. 69 DT-1 Yamaha. Not gonna spend as much on that one though. Gave myself a budget to try and stay within! I love these older bikes. And I appreciate the advice and help from everyone on here and being patient with me. Thank you!

Bullfrog wrote:OK, trying again to attach the photo.

[img]CylStudsLrg0326Cweb.jpg[/img]

Ed

You will have to upload your photos to a photo hosting website like Smugmug or Shutterfly or others first. Some are free, others are not. Then copy the image address of your photo by right clicking on it. The image address should start with http... or some such. Then paste it between the image tags [img] in the body of your post.

Contact your webmaster regarding photo uploads. The forum feature is currently not working. It shouldn't be necessary to take a photo out to another venue like photo bucket just to post here. Photos should upload directly from your computer under the full editor and preview options. Tried twice without any result, so I assume it isn't working and that it isn't something an ordinary user can fix.

Reading through this I had alarm bells going off in my head. I had a similar situation rebuilding a very early Super Rat. After SO much work, I was installing the head only to have the very same problem; one of the studs stripped. After walking away from it that evening, I decided, (during a sleepless night), to take the motor in and have timeserts installed, (timeserts are much better than helicoils, IMHO).

I *assumed* 8mm studs. I told the Machine shop to use 8mm timeserts. Imagine my horror when I try to install the studs and they were now too small! So, I purchased 4 3/8" bolts, cut the heads off and tapped them with a plan to tap the head nuts too. Nope.. Now the Cylinder would not go on, the studs were too big. Now I'm in a pickle.

Luckily I had a friend who works in a machine shop and after a quick conference with him, he put them on a lathe and returned 4 cylinder studs, pictured, to me the next day. 8mm on the bottom, 7mm on the top
Everything assembled perfectly after that. What I really liked was that the "shoulder" on the Cylinder studs actually locked the cylinder centered into place very nicely.

The Alarm in my head was that I suspect there may be Ace100 engines out there that have 8mm studs, but all of them I've come across had 7mm studs. Please measure your studs before installing timeserts or helicoils.

Lastly, I would encourage you to have timeserts installed. There was just enough room for an 8mm timesert so there should be enough for a 7mm. I did not disassemble the engine, but I did stuff the crankcase with paper towels and taped over the top and punched out the stud holes. I pulled the engine that morning, dropped it off on the way to work, and had it back in and fully assembled that evening. I think you may still be able to get on the trails before it gets too cold.

$0.02

Roger

Good call, Roger.

I have used helicoil frequently over the years. But the Time-sert looks like a better deal. A kit costs more, $70 - $80 for a kit with tools and five inserts versus $29 -$50 for the helicoil, but the product is far more substantial. I would be tempted to do all four if I had to do one anyway. One kit would cover all four studs.

Too bad Hodaka didn't make the custom 8mm x 7mm studs as standard equipment. I think that's a great idea.