488 on the bench

[Sam_choq]

My budy tell to me is 488 come to run bad ,
so i crank it ,*f-word a lot compression for a bad runner
i check with gauge 190..... not supose to be has high like this for a 488 .
Why ? because a lot of carbon !

i open the hole with finger....

 

[Sam_choq]

 

[backhoelover]

looks like some scouring on the cylinder

 

[Sam_choq]

I got some time for play with it and some olds cylinder .
Stock number is 102exh 122 transfer 70 intake
with 0.040 squish normal compression is arround 150 160


inside look


ring pin


cant go to wide and cant drop to much


2 ring go in the intake
43mm piston..

 

[Sam_choq]

looks like some scouring on the cylinder

yes but it is light

 

[Sam_choq]

Wich way would you go with it pro grinder ?
I cant drop much than a deleated gasket because of the piston skirt.
Anyone have long term succes with welding and machining on the top of the piston? I think piston is not 100% aluminium ?
I know it can be weld but probably not the same heat resistance .

 

[Sam_choq]

[emoji33]

Envoyé de mon SM-G920W8 en utilisant Tapatalk

 

[Sam_choq]

Someone here can have oem piston for the shidaiwa 488 ?!?

 

[Sam_choq]

 

[Warped5]

I'm thinking that's just a smidge on the lean side ....

 

[Sam_choq]

Holding 13500[emoji23]

 

[Jon1212]

@Four Paws @exSW

 

[Four Paws]

Cool project!

These saws are built really well. You can drop the jug plenty to get compression up - the chamber is small.

Focus on the basics - get muffler opened up, raise compression, port shapes, work the intake as much as possible. Looking at your tach it appears you got it figured out.

Site sponsor @fordf150 should be able to get you a new OEM piston and cylinder.

 

[Sam_choq]

Cool project!

These saws are built really well. You can drop the jug plenty to get compression up - the chamber is small.

Focus on the basics - get muffler opened up, raise compression, port shapes, work the intake as much as possible. Looking at your tach it appears you got it figured out.

Site sponsor @fordf150 should be able to get you a new OEM piston and cylinder.

thank you but i have find new oem piston .

yes i know is not a safe rpm but it limb with a big smile in the face like that , and still alive ....it is for play but still look like it can work hard and realy good on gazz

 

[Sam_choq]

Don't grind too much

 

[Definitive Dave]

Don't grind too much

Ouch!!

 

[Angelr]

The pistons shindaiwa, which marketed echo, are priced at oem here in Europe

 

[Angelr]

It works poorly the translator, I wanted to say that it is an original economic replacement

 

[Sam_choq]

I'm thinking that's just a smidge on the lean side ....

To lean ?not sure what you talking about .

 

[Sam_choq]

Don't grind too much

It was a big hit , face of the muffler to a tree , but it to thin too