Honda Spree and Elite 50 Forums

Just wondering, can't seem to find much on the subject. Would be interesting to get it up to 100cc..

No actual kit, but you can always use a CR80 piston.


"A European catalog for Wiseco pistons (an after market supplier) listed their 1984 Honda CR80R piston as being suitable for a "Lead 80" scooter. My Aero has almost a 1 inch wide boost port; substantially more than the total .820 inch spacing on the 1984 CR80 piston. The earlier CR80 (1983 model # 493) Wiseco piston has almost an inch between the pins so its the one I eventually installed. They come in sizes from 49.5 mm to 51.5 mm and wise co pistons should be available through your local motorcycle dealer. After buying the piston I visited my local machine shop who bored the cylinder to match the piston.
The Wiseco CR80 piston is in the scooter and it works great! I had to buy a CR80 wrist pin as well because the Aero 80 wrist pin was too long and wouldn't allow me to fit the pin locating circlips into the piston. I had removed about 1/16 inch or about 2 mm off the stock head and so the compression is higher. Cylinder pressure is 160 psi. The engine really wants to rev and I've re-installed the stock weights. I haven't been driving it anywhere that I could open it up yet but 70 km/h is easily obtainable even on mild hills. Acceleration is better than before but still not as good as I'd want. The engine revs and then the variable pulley kicks up and the engine bogs down until it increases speed again. Just another reminder that increasing engine power is only one part of the equation for increased speed and acceleration."

Hm... might have to look into that. Thanks bear.

EDIT: If I don't go this route, I think I will grab that kit on eBay for the Aero 80 with a new Jug, piston, gaskets, pin and clips for $100. This engine has over 8500 miles on it, I would think replacing all that would give some substantial power. After that, it's time to put on the Peugeot Speedfight 100 exhaust.

ragtop89 wrote:Hm... might have to look into that. Thanks bear.

EDIT: If I don't go this route, I think I will grab that kit on eBay for the Aero 80 with a new Jug, piston, gaskets, pin and clips for $100. This engine has over 8500 miles on it, I would think replacing all that would give some substantial power. After that, it's time to put on the Peugeot Speedfight 100 exhaust.

I would let the compression numbers be my guide on a top end rebuild. I have one that needs it (90 PSI) but it runs so d*** good I am reluctant to tear it down.

Bear45-70 wrote:

ragtop89 wrote:Hm... might have to look into that. Thanks bear.

EDIT: If I don't go this route, I think I will grab that kit on eBay for the Aero 80 with a new Jug, piston, gaskets, pin and clips for $100. This engine has over 8500 miles on it, I would think replacing all that would give some substantial power. After that, it's time to put on the Peugeot Speedfight 100 exhaust.

I would let the compression numbers be my guide on a top end rebuild. I have one that needs it (90 PSI) but it runs so d*** good I am reluctant to tear it down.

Going to do one this weekend, before I got it remotely running awhile back I think compression was 160psi. If it's anything under that drastically, I'm tearing it apart. I noticed a sputter of fuel leaking where my intake meets the block, it's a pain in the * to torque the intake bolts down because of how confined it is and no room around the intake. I'm thinking it might be old gasket material I missed doing it, going to get some thicker gasket though too, as the stuff I got with the kit is pretty thin.. That's probably hurting performance alone.

ragtop89 wrote:

Bear45-70 wrote:

ragtop89 wrote:Hm... might have to look into that. Thanks bear.

EDIT: If I don't go this route, I think I will grab that kit on eBay for the Aero 80 with a new Jug, piston, gaskets, pin and clips for $100. This engine has over 8500 miles on it, I would think replacing all that would give some substantial power. After that, it's time to put on the Peugeot Speedfight 100 exhaust.

I would let the compression numbers be my guide on a top end rebuild. I have one that needs it (90 PSI) but it runs so d*** good I am reluctant to tear it down.

Going to do one this weekend, before I got it remotely running awhile back I think compression was 160psi. If it's anything under that drastically, I'm tearing it apart. I noticed a sputter of fuel leaking where my intake meets the block, it's a pain in the * to torque the intake bolts down because of how confined it is and no room around the intake. I'm thinking it might be old gasket material I missed doing it, going to get some thicker gasket though too, as the stuff I got with the kit is pretty thin.. That's probably hurting performance alone.

Service manual spec for compression is 200 max and 142PSI minimum.

Torquing the intake bolts is easy with a 1/4" drive torque wrench and an extension with a universal.

I'll take a picture of it and post it to show you what I'm talking about, with the stock intake it was a piece of cake, but with the CT, it's a piece of * cake.

Once you get it that far down, and only a little torque, it's very hard to get any bite on it. Can't get a socket on it either, my wrench was doing good, it's mainly this left front bolt. Just once it's down, you have no room to get your wrench on there really to crank on it.

Also, my battery seems to not be making a good connection now. Not getting continuity from the negative anywhere on the engine, fuse is good. Maybe I need to check my harness.. pain in the butt....

This is the reason I do NOT use regular bolts. I use socket head cap screws.

http://www.amazon.com/Metric-Class-Blac ... B004N1ERU6

I don't use Amazon, I get them at the local hardware store.

Awesome. Thanks bear.

Getting some M6 x 16mm cap heads today bear, ill post results.

Worked perfectly. No more leak!

Quick question what is that clearish looking thing on it? Vasiline,silicone caulking? Some sort of materiel for testin leaks?

It was some blue gasket material, was gonna put some on there for the ride home from work, but changed my mind.