OS 105 Engine

[chrisleematt21]

I took my engine apart today for some maintenance and the piston and liner has a score mark on them.

Does it mean they need replacing?

Any ideas what would have caused it?

The bearings are a corroded but feel fine, not notchy or anything.

Also I can't seem to the carb off, it turns left and right but no movement what so ever upwards.

Its been running fine with no issues, but wondering if I should replace the parts no while its on the bench.

[waveydavey]

Hi Chris, examine the piston see if there are any corresponding marks on it or on the ring. If it's not deep, IE you can't feel it with your finger nail then use a little wet and dry and give a light polish. You can use a brake disk honer but a light rub will do. Don't go over the top with it though. Change the bearings, treat them as consumable and change before they need it. If there is corrosion then there will be flakes of rust ending up in the engine. As for the carb the plastic liner gets a ridge in it as you tighten it up and it swells the liner at the pinch bolt, nothing for it but brute force and ignorance I'm afraid. Gently shave the liner with a craft knife to remove once you've got it out, completely remove the pinch bolt before you pull.

[hedge]

Hi Chris, check that the piston ring retaining pin is still there, if it snapped off and went through the engine it might be what caused the damage.

[waveydavey]

It's difficult to see but is there a little nick in the piston ring where the rub mark is

[chrisleematt21]

The piston ring looks ok, I can't see any damage to it.

The little retaining pin is still there, could it be that I didn't run it in properly? It's the first nitro I have run in but I did follow this video on how to run it in and set it up, but may not have done it correctly.

It seems to have good power and runs consistently.

I have ordered a new piston , piston ring and bearings from RCJAPAN, does anyone know what the import taxes, vat , fees etc are when ordering from japan?