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

Aren't these engines full of surprises? Haha

I was also surprised knowing there is no way to fine tune the valves, mine has a faulty cam shaft which is the source of many issues I assume. I was thinking my R90s was difficult engine but at least with that one there is some room for adjustment.
Jin has upgraded cam shaft which I believe he would send to the customers. That will hopefully sort array of problems.
When I opened the crankcase to inspect the camshaft it came out with the case cover. And there are no cam timing marks to readjust it.

Hopefully Jin will provide a guideline.

I am not big fan of these tiny sparks, they are fragile and I think their life span is shorter than likes of 1/4-32. And can only find them through their ebay/starlingkits. With 1/32-4 spark type, RCEXL makes great quality both in standard and Iridium variant. They work great on R90s.

I got this engine to give as a gift to someone, but I think I will return it as the receipt is not that mechanically minded. I was expected the newer engines are defect free.