Probably a bit TOO lean...

[Neptune]

Making a long story short, I think I ran my Road Toad too lean on the needle. Bike quit on me about 1/2 mile from home. Depending on what I find when I take the head off, can this just be a new piston and rings or do I need to go oversize? I hate being THAT guy...

[thrownchain]

you wont know till you pull it apart. light seizure you might be able to "clean up" and go again, heavy scoring needs an over bore.....

[taber hodaka]

Bewildered? Does it have gas, spark and compression? Many things can happen to make a engine stop running. Jet too rich and then lean it back slowly. What you need to do if the engine stuck is measure and go by the specs.-----Clarence

[Bullfrog]

While it is 99.9% correct to say that all seizures result in the engine stopping running . . . far, far fewer instances of the engine stopping running are the result of a seizure. So just a teensy bit more information is required to help out here.
Ed

[Roddy boy]

I too had the "walk of shame", pushing my bike a half mile in the blazing sun. Turns out one of the wires in the stator had rubbed and shorted out. I would check there first unles of course the piston is seized tight

[Neptune]

When I pulled off the road I tried kicking it over again and I had no compression. So I fear the worst. I was running it on the exact same needle position and premix ratio of the previous owner. He knew what he was doing; me, not so much I'm afraid.
What if I pull the head and the piston crown is fine? What should I check?

[Neptune]

Update, the piston crown itself looks fine. Plug looks great. The bore, not so much. I didn't pull the actual cylinder off yet but I think it may not be bad. What specs do I need for the bore?

[Bullfrog]

The easiest first check is to remove the exhaust system and take a look at the piston and ring through the exhaust port.
Ed

[Bill2001]

Hey, it's deja-vu all over again...

[Neptune]

Should there be a mark on the piston that shows the size somewhere? I have no idea if this thing has been bored over yet. I could measure the bore but do I measure about 1" down from the top?

[Neptune]

So the piston has what looks like 0.10 stamped on it and the cylinder has a +2 stamped on it. Nominally the bore is 1.975". What is the significance of the +2 on the cylinder block?

[Bullfrog]

So the 10 stamped on the piston indicates that it is .010" over-size, or the "first over-bore". The +2 stamped on the cylinder was an indication of bore size on the original bore at the factory. That +2 has no useful meaning what-so-ever now.
Ed

[Jack Elliott]

I had a situation recently when the bike locked up solid and I was sure it was seized. then it freed up but seemed to have no compression.Fortunately I had felt that "no compression" feeling before and checked the clutch which had fallen apart - temporarily jamming the engine solid.
Not suggesting thats whats happened in your case but its always worth checking the easy things first!
Now my clutch is held together with Nylock nuts and High tensile bolts (thanks for the advice Kev)

[Neptune]

This never locked up solid, I was running it pretty hard and it just kind of pooped out and wouldn't start. Even after i let it cool down I didn't have any compression. Piston is missing some material off the sides below the ring, that material is goobered onto the cylinder wall. I've had good luck in the past using acid to get the aluminum off the cylinder wall and then just giving it a quick scuff with 600 grit for new rings to seat.
Bullfrog thanks for the info re: markings. That gives me a direction to start in.

[viclioce]

You're likely going to have to go to a .030 or .040 oversize. I played Hell trying to find a .020 piston for my Model 99. Got a piston from a forum member and rings through a shop Bruce knew.

Good luck and remember you can ask for either Road Toad or Dirt Squirt pistons as they are the same. SH, Hodaka-parts.com and Hodaka Dave are all people to check with. ; D Victor

[Neptune]

Thanks for that. I didn't know they were the same. I've got my hands full this week but hope to deal with it after T-day.
According to the SH site, the .20 piston kit for a dirt squirt is available, but it says 80cc's. Is the DS a shorter stroke but same bore size?

[Bullfrog]

Victor was referring to the Dirt Squirt, Model 01 which is 100cc and has the same engine as the Road Toad, Model 99 and 02.

The 80cc Dirt Squirt, (Model 82) piston won't help you out. The 80cc Squirt has the same 50mm stroke as the 100cc Toads and Squirt, but only a 45mm bore.
Ed

[Neptune]

Ah, okay. Thanks for that.