Tonka sounds familiar for sure... the guy who rode these bikes up here and also at some point obtained all the remaining spares from the old dealer years ago is named Bill Miller. He had 2 of these bikes back then. It's a small, small (Hodaka) world. I met Bill Miller's son at a bike show a couple ...

I believe 70's XL250/350 sprockets share the same spline dimensions with the SLs.

Conclusion and Resolution: Alright, got the cylinder back from the (second/other) machine shop now. To create a .003 piston-to-cylinder clearance they said they had to hone it out an additional .0015 to .002 :shock: . No wonder it seized :roll: . As for every action there is also a reaction. Accordi...

Well so far no opinions came through regarding this piston seizure damage. Hmm, wonder if I'm THAT Guy :lol: In any event, I have some info now so that other may learn from my misfortune :cry: : I took the piston and cylinder to the other machine shop. We have two and I went to the first one -- main...

OK, the piston is out now and revealing the secrets of its seizure: Things to note: - The piston is ART (cast) not a Wiseco -There are five new marks: two beside the piston intake port; and three on the exhaust side (one wide mark flanked by two narrow ones. -The top end has gone 500 miles at this p...

I think you have to at least remove the head to get the oil tank out. Otherwise, If the tank is a total loss then maybe chop it up into smaller piesces with a Sawzall/reciprocating saw. As for the oil pump, probably best to remove it and forget about it. SH has oil pump blank covers to cover the PTO...

Why did Frank Wheeler have all the luck with his Hodakas? The piston went "groink" while riding my Wombat (with a combat piston and ported cylinder) this weekend. I pulled on the clutch fast and stopped the bike for awhile. It was a temporary seizure -- been down this road before -- and I ...

Flushing, and or replacing the main bearings won't be too onerous as I've already have the cases split to attend to this bit of nonsense: IMG_1062.JPG This incident followed this piston melt down earlier this year: IMG_1062.JPG For what it's worth the intake side of the piston has fine vertical scra...

Always hoped to see an index. The Resonators are a gold mine of information and enlightenment, but you never knew where to put your shovel and start digging for specific subjects.

Three Cheers!!...

%*&#@!*!! Sorry about that -- photo dropped off the last posting: 250SL Yellow arrow indicates exhaust

Further to my previous reply, I think I should clean up the scoring anyhow. Is Scotchbrite the way to go in this day and age? Historically, we may have used 400 grit emery.

OK, I'm back now with more pics and feedback. Note to Ed: The bright areas on the edges of the piston crown are clean and show like an out-of-the box piston without detonation damage. I've included a pic of the combustion chamber too. The carbon pattern was symmetrical when the engine came apart, I ...

I'm wondering if a small filler neck fuel tank (possibly Ace 90/100 --to be determined) will bolt straight onto a Wombat. Owing to Hodaka's design philosophy one might think so. However, I already checked the Part Compatibility spread sheet and it doesn't indicate that any tanks work across differen...

Bullfrog wrote:Would you indicate exhaust/intake sides for us on the piston crown photo? Comments after getting that information.
Ed

Thanks Ed,
The exhaust side of the piston crown is straight down.
Additionally, the cylinder is a bit scratched too (visual and finger-nail inspected).

Upon tearing down my 250SL to replace a sheared countershaft (another story) I discovered scoring or scratches on the exhaust side of the piston and cylinder. The top end has about 450 miles since the .010 rebore and new Wiseco piston. I also took it apart at 150 miles because I was second guessing ...

What D. Victor said... I was running a 35-36:1 ratio with 94 octane, mainly because that lean mix is what my 94 Wombat required or else it would foul plugs. However, I've been getting exhaust side piston and cylinder scuffing using that ratio with my 250SL - so now it gets a 32:1 mix (Yamalube 2R, o...

I'm wondering...would there be any side, or adverse, effects from running a Wombat piston in a Combat Wombat (Victory-Ported) cylinder? With out the piston port where will the intake boost travel?

Thanks everyone for the brainstorming on this breakdown. It's my practice to tighten the sprocket nut with an impact wrench. I try not to use all of its power thought and sort of let it coast into the until I get a couple of rattles. The tab on the lock washer was folded up as it should be and the l...

michael_perrett wrote:Cracked Toad cylinder, countershaft splines gone, what is happening to the world. I would try welding, just to see how it holds up, but would only ride uphill from the house.

Mike Perrett

Maybe the metallurgy has gone past the "Best Before" date?

This happened on my 250SL at the end of a great ride: IMG_1005.JPG IMG_0999.JPG The sprocket did a nice job of machining the new groove on the counter shaft. The sprocket came through the ordeal none the worse for wear, and this is the first time I've ever seen this type of breakdown. Anyhow, I'm th...

Well, that's a new one on me! So, no, I sure wasn't going to guess that! Ed PS: Yeah, I'm thinking welding the countershaft sprocket on is probably not a good idea. :-) I found the problem when I stuck my thumb into the countershaft (clutch side) and rotated the rear wheel. When the countershaft di...

With stock gearing the manual indicated the bike can be ridden at 55mph for extended periods.

Was anybody going to guess that the countershaft sprocket stripped the splines clean off of the countershaft :cry: ? That's the problem with my 250SL now. Does sort of breakdown happen everyday? I'm tempted to weld the sprocket to the CS -- but I suppose that's kind of lame. I just put the cases apa...

I'm going to try the control shaft and if seems OK I'll pull the clutch.

Clutch action went from 100 percent up to the stoplight, then barely getting me across and intersection at the green, then no clutch on the other side.

Check that the float level is correct. Sounds like the float has to rise too high to close the needle.

Although a bit of a long shot, there was a instance here on this forum where one of the pressed on mainshaft gears spun on the shaft. The test is easy, does the bike work in any of the other gears? In this case all of the gears are dysfunctional. I'll have a chance to pull the clutch off tomorrow a...