HELP! Piston ID

[bobwhitman]

Sometime ago, a useful pictorial was posted here, I believe by Paul Stannard, when he was selling parts,. The posting showed and neatly explained the difference between high dome/Type 1 and low dome/type 2 pistons.

I need a clean copy of this post, if anyone can help me find it. Information needed for the next Resonator article(s) about 100cc Hodie pistons.

I can scan & print, if I can locate a posting or if you have a print to copy.

Appreciate any help
Bob

[dirty_rat]

Bob,
Here is a photo of the two side by side. You can see in the photo that the Ace piston (2 ring) has a slightly higher dome than the Super Rat piston.
I remember reading the article about the differences, just don't remember where it was. I will continue looking for the article and send it to you if I find it.

[dirty_rat]

Bob,
Here's a copy of a post from 2017 that talks about the article at the old Strictly Hodaka site. As that site no longer exist I don't know if the information is still available. Best chance of locating it would probably be to contact Paul and see if he still has it on his computer. Also might check with Terry and see if he has it somewhere on his computer.

Good luck.





Re: Hodaka pistons

Post by dirty_rat » Sat Feb 25, 2017 12:30 pm
Richard, probably just a typo on your part, but the 93 piston is a 100cc piston, where the 94 piston is a 125cc piston.

As far as I know, all the 100cc pistons are the same as far as piston pin placement, skirt length, etc. The biggest difference with any was the dome shape (height). The Ace 100 style 2 ring pistons had a high dome and came only on the Ace 100's (all types) and the early (96) Dirt Squirt. The low dome pistons came on all the aluminum cylinder 100's and both of the Super Rat's. The early Super Rats pistons did not have the reed valve holes in them (but you can drill them in).

For a complete description (even has pictures) go to the Strictly Hodaka site and under FAQ go to the TECHNICAL TIPS & SERVICE HELP. Under that tab is a long explanation of the two types of pistons for the 100cc engines.

Hope that answers your question.

[Bullfrog]

See the "Archive" section here on the Forum. No photo - but some data. Thread is about compression.
Ed

[dirty_rat]

Here is all I have been able to locate so far, it's from the archives:

Forum Admin - 01/22/07 at 9:11am

Jack the message Ed left is totally correct but I would like to try and add to it. I believe the crown height of the Ace 100 pistons ( double ring pistons) was aprox. .065 " taller than that of a Superrat single dykes ring piston. So if you use a Superrat head ( #932501) while using a stock Ace 100 piston I think ( big guess) that your compression will be well over 190 lbs. But as Ed said check it. When you do check your compression your motor should be cold. If the motor has not run in 3 weeks then give a squirt of wd-40 through the sparkplug hole in the head to seat the
ring(s). Also hold your throttle wide open while kicking the bike to check compression. Let us know what your compression is please when you get a chance.
Paul

[MTrat]

I recently bought a Dirt Squirt from Tom Rapp who got it from Jim Pomeroy at Hodaka Days lang ago. The bike has a
Webco head with a Rat like compression profile. A standard Ace piston is used but two head gasket raised the head a bit. I assume this was to lower compression/clear the piston crown. Any thoughts on this?

[dirty_rat]

MTrat,

I know a lot of Webco heads were actually designed to run without a head gasket, so two would indicate someone was trying to lower compression.
An easy way to determine a possible reason would be to run a compression test of the bike with the two gaskets and then try it with one gasket. Just make sure the piston won't hit the head when you run the test with one gasket.
Webco did also make heads specifically for Ace 100's and for Super Rats, with different combustion chamber sizes and shapes for each.

[bobwhitman]

David
Please email or text me your email address so I may thank you for your help & send you the announcement I’m working on.
[email protected]
541-954-0-01

[dirty_rat]

Bob,
I sent you an email. In case you didn't get it, my email address is:
[email protected]

Also, your phone number is missing a number!