The Hodaka Club Forum

Awesome! Looks like you will have it together in no time.

Yes the original Toad piston uses a dykes ring on top
Rich

I love this subject .
so many posts helping Vic sort this out.
Read SoCals post with great images - you couldnt explain ring gapping better!
but then The Captain takes it one step further showing you dont even need a photo-
you've just got to figure out which keys to use.
Sorry I know I am not adding to the technical side with this post
just getting a warm fuzzy feeling reading it.....

One of the reasons figuring this out has been difficult is because both motors had disassembled top ends. One had a fresh .020 bore with an SH Wiseco piston and a set of loose new rings in the manual. The other had no piston, no rings and no cylinder. I guess I did too much assuming when acquiring top end parts, and was exaserbated by the short supply of Road Toad top end parts. To date, I have bought 4 sets of rings, all claiming to be rings for a Road Toad. So I am glad I'm finally getting close with this last motor! Truly, without a forum like this & its combined knowledge sharing, I would have probably given up on these Toads! Thanks to all who have pitched in! ; D Victor

Piston rings need to be bought according to the piston you have, not the model that they go to. All sets you bought will likely work in the Toad, as long as they match the piston.

One assumption that is probably safe to make is that these old bikes have been repaired again and again, and parts may not be original or correct. Assume that parts may be mixed-and-matched. Worst case situation is that nothing is correct until verified otherwise.

Clarence. I was buying rings that were labeled as NPR rings for a Road Toad but no piston description was given. I was (incorrectly) under the impression that if they were RT specific that they would have been for an Art piston since SH holds the rights to the Wiseco Paul designed. One set, though in an NPR 100 50.50mm box labeling, actually turned out to be 125 piston rings. The seller had put the wrong rings in the wrong box at some point and so I have a set of rings for a 125 at .020 oversize. So it isn't just a matter of believing I know what I need, but also finding out if the seller knows what they have and if the description is truly accurate. I can only go by what is shown and how my questions are answered. There are obviously a lot of folks out there who 1. Don't know what they really have to sell and 2. Don't know what Hodakas use and what size listings are and never measure things like rings to find out it they match what's on the box. I actually had the seller who sold me the 125 rings by mistake tell me to keep the rings & he issued a refund, no questions asked. So I have a free set of NPR non-dykes rings I will likely never use. ; D Victor

I notice when I look at the Dykes ring that the outer dyke(?) has a slightly larger diameter than the inner ring. I assume that's to allow it to overlap the ring pin, right?

So, does this mean I need to set a gap for both the dyke outer to still close while fitting the ring pin in between the inner part of the ring? I haven't started filing yet, but I've been contemplating these thoughts.

So, file the inner ring for gap and file the outer (dyke?) for ring pin overlap? Bueller? Anyone? Bueller?

File the vertical leg of the "L" to achieve the gap - file equally on each side of the gap - needed when the ring is installed all by itself in the cylinder. Then remove material from the horizontal part of the "L" if needed to assure that the ring does not pinch pin. Filing a bit of extra clearance here to be sure of no pinching is not a problem.
Ed

OK! Thanks! ; D Victor

This is a good reason to get parts from SH or the usual Hodaka Parts suppliers. There are so many nuances in the that go beyond just the correct part number.

Old bikes. Always an adventure.

Vic,
Have you measured the end gap of the ring in the cylinder? If you have done this you should know in advance how much needs to be removed, if any. When you do place the ring in the cylinder for measuring use the piston as a leveling device to ensure that the ring is "level" in the bore, as Kelly showed in his photos, otherwise you will get a false measurement. Use a feeler gauge and take your time. You may find that the ring is fine as is and your initial problem was that the ring was installed upside down on the piston. Good luck!

Ivan. I have yet to be able to fit the cylinder on even turning over the dykes ring. So I can't deterine a ring gap yet. I'm going to have to slowly, carefully file the ring down until it fits and then measure the ring gap. I also want to clean up my work bench & garage because I'm running out of room!

I also bought a second cylinder for the first Road Toad and will have to check ring fit for it as well. At lease all cylinders were claimed to be bored to .020. Hopefully that will still prove to be true and things will go together correctly now! ; D Victor

Vic,
Take a look at Kelly's photos on page 1 again. Photo 3 shows the ring in the cylinder, properly "squared up" in the bore by lightly bumping it into alignment with the piston - then Photo 4 shows checking the ring gap with a feeler gauge. All this is done before any attempt to install the cylinder over the piston/rings when reassembling the engine.
Ed

Vic,
As Ed said do not start filing the ring without doing a fitment test with it off the piston. If it fits in the bore with the proper end gap "squared up" (I like that term better than leveled) and still doesn't allow the piston to be fit into the cylinder when on the piston, something else is going on here. Photos would help us identify quickly whether you have a piston designed for a Dykes ring. If the circumference of the piston above the top ring groove to the crown has not been machined to allow clearance for the vertical part of the Dykes ring it will never fit no matter how much end gap you have. I hope I explained this well enough to be helpful. Sometimes I can't get my point across even though it is clear in my mind.

...and other times, as Ed will attest, I'm just plain wrong...

OK. First, Racerclam ( Rich G.) sold me the piston and told me is an original Art piston for a Road Toad. I trust him on this. He's a machinist and rebuilds, ports and strokes Hodaka motors all the time. He also said definitively, the Art piston takes an upper dykes ring. This is confirmed.

So my next step is to pull the piston off the rod, set the ring inside the cylinder and check it and determine, hopefully with some kind of accuracy, what amount of filing it needs.
Not having a manual for the Toads and failing to read the ring gapping procedure in my Wombat manual, because my Wombat went together without needing to do this, I simply assumed the Road Toad would as well.

I know I have a .020 piston & .020 rings. What I don't have is a measuring device to determine if the cylinder is in fact a .020 oversize as told to me.
The rings are confirmed because Bruce got them for me from an engine builder, based on my size request. So there you have it.

I need to get some free time to work on it. Pics will follow as soon as I have them! ; D Victor

Check the piston-to-cylinder clearance. Ringless piston in cylinder, a 0.003" feeler gauge should fit betw the piston and cyl. No less than .002 and not more than .004. This is the important value. The piston OD and cylinder ID are just measured to arrive at this value.

Well the piston clears fine. Still haven't pulled anything and worked on it yet. Class this a.m., then had to pick up a check, then a funeral of an old friend, then pick up my grandson at school & take him to PT, then Dr. Appt for means now my son in law's surprise 40th Party this evening!!! ; D Victor

OK! First off I want to say Happy Thanksgiving to all the Hodaka forum members!

It's not too cold today & I had some time. So, first off I pulled the piston from the rod. I also set the top dykes ring, which was having trouble with clearance while on the piston, into the top of the cylinder. It seems to fit fine without the piston, & it appeared to have a gap roughly almost twice as wide as the pin on the piston, from the top side of the cylinder (see first photo).

When I insert the piston ring in the lower side of the jug the gap is a little bit larger, but not by much, visually (see second photo). If really needed, I could attempt to measure the pun gap with the ring as level as I can make it at both ends, but I guess my point is there doesn't seem to be a reason why this .020 piston won't go in the jug with this ring on it. There appears to be enough clearance for the ring, albeit slightly tighter at the top of the cylinder than the bottom.

Piston with the lower ring goes right in and fits snug but moves even without being oiled (only slid it a tiny bit).

OK. So now I put both rings on and it goes right into the cylinder without effort when I colapse the rings with my fingers!!!

So, why is it being so difficult when the piston is in the rod??? Thoughts? ; D Victor

Here's a side view of the piston, with both rings in place, sitting inside the cylinder! It's even oriented with the intake ports on the piston lined up with the intake ports on the cylinder.

Why the HECK would there be problems getting it into the cylinder with it connected to the rod??? It's not like this is my "first piston rodeo?!?!?!" ; D Victor

You have already proved the piston and rings will go in the jug so try again. Mark the locating pins with a sharpie to help keep every thing lined up and it should be fine.
Terry

Terry, I'm going to do better than that! I'm going to leave the piston as is in the cylinder and drop the whole assembly over the rod and push the wrist pin in place. I just hope I can get the circlips on with everything together before seating the cylinder! ; D Victor

Vic, Happy Thanksgiving! My advise, given for free (which is exactly what it is worth), is to take a deep breath, slow down, and while you have things apart do it right. Don't check clearances with your eyeball. Cylinders are usually bored to match an actual piston in hand. That way the clearances will be specific to that piston. There are slight variations from piston to piston even though they are nominally the same. Same with the rings.

Firstly with the rings off the piston, install the piston in the cylinder and check the piston clearance with a feeler gauge. As Bill said it should be about .003", much less and it might be prone to seizure.

Now insert the rings one at a time into the cylinder and use the piston as a tool to push the ring down about 1" into the cylinder. By using the piston the ring will be squared up in the cylinder. Now check the end gap of the ring with a feeler gauge, not the gap for the pin but the actual end gap. The gap should be about .008" In the first photo it looks like it might be tight but I can't tell without a feeler gauge.

If the piston with the rings mounted will fit in the cylinder while off the rod, it will fit while on the rod. It's handy to use a piston holder like Max's tuning fork to hold the piston while mounting the cylinder over the rings. On rare occasions on some engines I have put the piston in the cylinder and slid the whole assembly down to the rod, but it's not the easiest way to do it. If you take your time it will go together I'm sure.

Good luck and let us know how it goes.

Pop! I quit working on this motor because I was tired and frustrated by it. I've had plenty of time to cool down. The cylinder was not bored to match anything. The cylinder came from one resource, prebored, the piston from a second and the rings from a third. All I could do was specify the over sizes.

Now that I have figured things out, I plan on making a tuning fork style block of wood to hold the assembly while putting it together. I'm hoping that way, I can do the ring measurements, file as needed, reassemble the piston & rings on the rod and drop the cylinder in place.

I guess I just allowed myself to get frustrated because the Wombat went together so perfectly, not knowing it wasn't the "norm!" I did no ring gapping, no piston work, everything just fell into place and it's got great compression and performance. The only issue with the Wombat was the carb, and Greg (Zyx) sent me a replacement which works great now, & he fixed what was wrong with my old one and gave it to someone else on the forum up in Athena this Summer. I know who it was but my mind is going blank right now.

I've been working on these 3 bikes since February. I wanted to be done before the end of Summer but that obviously didn't happen. But I'll get there. I didn't slow down, I stopped for about 6 weeks. Now that the colder weather is here, I'll go back to the garage with a portable heater, and finish up.

When I'm done with the Toads, I need to pull the bottom end out of the Ace because I'm pretty sure the kick shaft bearing retainer gave out and I need to put the one from the spare bottom end I have in it.

Thank you to all the forum members for your guidance, support & commiseration! ; D Victor