The Hodaka Club Forum

Can a Super Combat be safely over bored 8th over or will the cylinder skirt become too thin ?
I know a combat wombat can but the SC is a higher performance engine and I'm not sure if that might make a difference

I t wouldn`t scare me. I can`t say concerning a Super Combat, BUT a Model 93 can. Remember: When a cylinder is bored + .080, .040 was removed from the cylinder wall. What I would do in your case is take your cylinder to a machine shop and see what they say. Here`s the problem: The guys that know don`t post in this site. They make their money building engines and helping you out makes them NONE.That`s right guys! Throw the insults at me. I could give a Flying Cow pie! The self proclaimed Hodaka Wizards out there haven`t responded for 1 of 3 reasons: They haven`t read your question yet, They don`t know, or they don`t care. Another fact: Just because someone has been doing something for 50 years doesn`t make them good at it. Fact! Joe Ormonde.

Joe take deep breath!!! It is well known in the Hodaka World, that yes a cylinder can be bored to 80 oversize but is not recommended. Why, not reliable, and parts over 50 oversize are hard to find, both pistons and rings. It is not recommended. Ok what is recommended, up to 40 oversize is most recommended only. I am not an eng. builder, but I have kept a close watch of all Hodaka Forums and there found what is recommended, by the as you call the Hodaka Wizards, it,s common since, don,t overbore too much, these little engines where not made to do anything over 40 oversize. Many of the new owners don,t take the time to get a Manual and also don,t do their own homework, or ask the right questions, or ask without out have all the info included. Sorry, I think your are a little off base. Please lets not turn this forum into a war room, we are all above that. Lets use it for constructive purposes, to help each other. Remember if we get to out of hand the administrator can step in and take actions we all don,t want to see. Please lets help each other. bruce young

can you get an .80 over piston and rings?

Well , I can get the oversized piston and ring for a Combat Wombat (wise one) and drill holes in it, and , the machinist said I'll have to throw away the cylinder unless I bore it as big as it will go due to rust pits that are too deep. He doesn't think he can sleeve it because of the cast in ports. I think finding another cylinder is not an option unless I wait for one to show up on eBay and I can snag it before someone else does. Has anyone on this board ever bored over that much on an SC ? If so any piston/cylinder related problems ?
Thanks. Rick

That was meant to say Wiseco not wise one

Willoughby, give me a phone call I will give you several phone numbers to try and find the size piston you might want, and even a cylinder maybe. 1--208--571--2823 Bruce Young

As a certified "old fart" myself, I had been thinking for several days that I ought to respond to Willoughby's original question . . . but my response wouldn't have been quite as cantankerous as Joe's - though I would have made at least a couple of the same points.

It is quite likely that many of the engine builders/boring service providers who KNOW the answer to the question simply haven't seen the question. I know of several who are "old school" and don't mess about with computers, but work magic on Hodaka engines.

Apparently there aren't many (any?) readers of this forum who are actually running an .080" oversize piston in a CW, which isn't too surprising. So responses from that group are severely self limited.

. . . and (thankfully) there weren't a lot of responses which started with, "I've never done an .080" over-bore before, but . . ." (And since my own response would have had to start that way . . . I was a bit hesitant.)

Joe is right, the factory engineers only envisioned going to .040" over-bore, but larger over-bores are possible and serviceable.

Finally, (while I haven't done this one either ), I am sure that re-sleeving can be done -- though I think I'd go to someone like Superior Sleeve with decades of experience to have it done
Ed
PS: Peace and the Golden Rule (the other Golden Rule . . . not, "Them that has the Gold, makes the rules." )

Hi willoughby ,
I am not on the forum much any longer but just happened across your post the following responses.

We are now out of stock or running very low on our piston kits. I had deliberately let them run down as we at SH back down from our reproducing of expensive parts for the Hodaka's. As I am not out of the game yet and have received many many calls for piston kits that we no longer have or offer I am strongly contemplating another large piston production run before I bow out. This will allow a lot of folks to find at least for now the pistons that they need. I disagree strongly with Bruce Young saying that
" 80 oversize but is not recommended. Why, not reliable, and parts over 50 oversize are hard to find, both pistons and rings."
Our manufacture of modern piston kits is Wiseco. Wiseco has been making oversized piston kits for Hodaka's up to +.80 for 40 plus years.I had been offering at SH piston kits up to +.80 for 30+ years and I do recommend going that far if you have to. I have a great friendship and relationship with the managers at Wiseco and we work very well together and have for years.
The engine cases will need to be relieved after +.50 but this is an easy task.
At one time we produced and had in stock for the Combat Wombat/Super Combats 20 +.50 size, 20 +.60 size and 30 +.80 125cc pistons. They are now all sold and we have not had nor know of any issues at all. I just felt obligated to give you another opinion regardless of flying cow pies and all the rest. Good luck with your project!! Paul

Just a little personal perspective from related experience. My Road Toad motor, on its 8th overbore, melted down like Three Mile Island. Heat dispersal on the thinned out cylinder was determined to be the likely culprit. I'm not saying don't do it. I am saying it may be a long (and expensive) run for a short slide.

I think the reason that motor builders may not give rebuild advice may be that they could be blamed if it fails after. "Bob" said it could be done, now my motor is junk, "Bob" was wrong and doesn't know what he's talking about, when "Bob" didn't have any direct hands on with the build. "Bob" has no control over the build, but takes the blame if it fails.

Good point, Dan. I kind of look it as a "if you have to ask" situation. How many of us do our own cylinder boring anyway? Other than a quick spin with a ball hone for a top end refresher, I don't, nor will I ever, do any reboring. There are pros for that and they stand behind their work. That's the guy I want doing my boring when I'm approaching a jump face or 10 miles out in the middle of the Chippewa National Forest. Back to the original thread, Charley Brown at Superior Sleeve could probably sleeve a weed whacker motor if you asked nicely. He did my 1978.5 RM250C2 several years ago and at least 100 hours ago and the bike rips. No loss of compression since the original work. He's a master. Send him your jug. If it can be sleeved, he's the one to do it.

Well hopefully , I can make a Combat Wombat piston work. I ordered one from you, Paul ,last week(I must have gotten the last one?) so it should show up soon. I wasen't aware that the cases had to be relieved. What exactly do I need to do to relieve them and how much material gets removed if any ?

I can't comment on the 125's, but I have run a cast iron barrel Super Rat cylinder with an .080 over piston (Wiseco) without any problems. It lasted as long, if not longer, that a new standard bore cylinder with an ART piston. If your cylinder is damaged to the point that only an .080 overbore will clean it up, I would say go for it. Your other option would be to contact one of the companies that will plate a bore (chrome or nicasil) and see how thick the plating would be (to give a slightly smaller final bore size).

We just installed a 6th oversized drom Paul in my son’s Combat. The Case needs to be relieved just a bit down where the skirt of the piston goes below the splinter sleeve. My machinist did it by getting the bore size, then attaching the cylinder to the Case halves, then running his boring bar down a bit past the skirt to get it perfect. Your mileage may vary.

I hope, Paul, you get the bug to do another piston run, or maybe talk Terry into it. Unless I can find my son yet another decent CW cylinder, we won’t be able to do another bore on his after this one runs out. Hopefully that will be some years down the line, but . . .

Excellent !!! SHARE YOUR KNOWLEDGE ! My post was WAY too radical and I admit that. But now the treasure trove of knowledge has been released ! Keep it up! It just seemed to me that the guys with the knowledge have been stingier with it than their private parts stash. Iv`e been reading all these posts in this forum from nearly day 1 and am ever so happy that it didn`t turn into (The Friendless Hodaka Owners Forum) where all they post is photos of their bug eaten vegetables. Joe Ormonde.

Hi Gary,
I am already looking into the possibility of a new production run of pistons this morning. If I do it it will be solo as Terry has enough going on right now to keep him busy for quite a long while.Knowing from first hand experience he will have to pace himself time wise and financially.
With his passion it will work out great for Hodaka folks.
Paul

Thank you all for the great info and thank you Gary, I see what your talking about on the cases. For .080 over it looks like half a millimeter has to be removed. I suppose this is why you want the Hodaka specialists working on your engine and not the local machinist . My machinist is a craftsman but he didnt realize that part of the process was necessary
Thanks. Rick

Hi Hodaka Community,
I have finally got around to inventorying my NOS pistons and rings. I added over 1500 pistons and over a 1000 rings to my website. I hope this helps out the Hodaka faithful for a while. Unfortunately I don't have all models and all sizes. This may help Paul determine what sizes needs to be made to fill the voids of his and my inventory. Our goal is hopefully to keep most Hodaka's up and running for the next few years. I still have boxes of Wiseco and other brands of pistons and rings to go through, but that will be much later. Check it out at http://www.Hodaka-Parts.com. Thanks, Terry

Thanks, Terry and Paul! I have three Hodaka projects lined up now- a Wombat, a Rat and something that will evolve from a dirt squirt motor! I anticipate needing some bits and pieces from both of you!

The ongoing commitment to the brand is really quite amazing. I am heavily into the vintage Yamaha Enduro scene, and the Hodaka community should be thrilled with the support these guys give back. It takes a hunk of investment to repop most parts due to the initial mold/design/setup costs. You have to order a crapload to make the per price amortize the up front costs, and then you gotta make some money on the deal, and expect it to take a decade to get them sold.

A big kudos you anyone who takes on a repop project!

New pistons? Was that a collective sigh of relief that I heard yesterday?

Regarding oversize pistons, my only experience is with a .050 over in a 95 Combat Wombat. It did require a little extra clearance added to the cases which was quite simple with a dremel. I assemble my own motors but use a well known Hodaka builder for my machine work.

If the need arises to go bigger than .050 over, I would first consider having my cylinder plated. Nickesil plating by Powerseal USA is great. You end up with the same bore size as it was but more durable than new. That said, I would not be afraid of running the bigger sizes up to .080 other than shortening the life of the cylinder by taking it out to the max.

I chuckle at the notion that Hodaka builders might not be commenting due to concerns about making money. The Hodaka faithful are not known to be big spenders. The builders I know have a passion for what they do and for the Hodaka brand.

My 10 cents...