Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

Hello to everyone,this is my first posting and a shout out to Jin.The piston on my M91 engine has become badly scored and needs replacing along with a new piston ring as it's blowing fuel out of the crankcase vent.I have emailed Jin through his contact page on the Microcosm web site but have had no reply.
So i'm hoping Jin sees this and can tell me what it would cost for these parts to be sent to the UK.Many thanks Trevor(eec1910}

Hello to everyone,this is my first posting and a shout out to Jin.The piston on my M91 engine has become badly scored and needs replacing along with a new piston ring as it's blowing fuel out of the crankcase vent.I have emailed Jin through his contact page on the Microcosm web site but have had no reply.
So i'm hoping Jin sees this and can tell me what it would cost for these parts to be sent to the UK.Many thanks Trevor(eec1910}

Hi, I'm sorry because there are still vacations. At least until the end of this month to work properly. Jin

Jin's holiday is extended not by choice but by the effort to contain the spread of the coronavirus. His work place will remain closed for a couple more weeks.


As for the piston, sorry to hear you are having problems.


This will not happen if you set up your engine properly and use a lot of marvel mystery oil in your fuel. 15 to 1 is a good mix.
The fuel should be Coleman fuel (white gas) or ethanol free fuel such as 100 LL aircraft fuel or another pure fuel.
Also retard the timing to top dead center and reduce the spring tension on the governor. This will get it slowed down.
You can run with just one slightly stretched spring or put two fresh but much softer springs on your governor weights.
You must also remove the crank case vent plug to run it. This way it will freewheel longer between hits and run much cooler.


I also like to shave 100/1000 off the piston top to reduce the compression and put a small chamfer on the top edge and the skirt.


I run mine alot and there are virtually no visible signs of wear.


Gil

This is a message for Jin,glad to see your back in business .I sent another message beginning of last week to your microcosm site for the price of a new piston and ring for my M91 engine but have had no reply,so i'm hoping this will get through to you.
Thanks Trevor.

Thanks for the email address Jin,i sent you a reply at midday UK time yesterday have you received it yet.
Cheers Trevor

Hi Trevor, Please try to keep in mind that Jin is extremely busy right now trying to get caught up after a forced 6 week shut down.

Jin don't know whats going on with emails as all others are getting through.
Can you try this one instead shirleywhirley62@icloud.com.
Thanks Trevor

Nick you may be right I didn't realise I put the fullstop after the email address.
So the correct email should be trram@tiscali.co.uk
or shirleywhirley62@icloud .com
Could you try these Jin
Thanks Trevor.