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

I discovered something bizzare. When I connect the multimeter to the ground and output (black and blue) of the hall sensor when power is connected to it. I can hear the spark when I rotate the flywheel. As soon as I take the multimeter connectors off it stops. It happens even with the multimeter off. On the continuity setting It only shows 0L even when the magent passes the hall sensor


Is this the hall sensor or something else ?

I definitely have to agree, Mr Jin is great about replacing parts when someone has an issue. 
I swear I don’t know how Mr Jin has the time to design and build so many beautiful creations.
Every single engine he engineers and builds are so detailed.

-It’s easy to see that He takes so much pride in each of his engines. 
Gotta applaud him 👏👏

I've only ever purchased through eBay, and I will just send him a message with some pictures of the issue. I have only requested action from him twice regarding parts, and he/his team responded in a day or two. Pictures are the important part, I fear the translation tools may not always translate technical words correct and pictures skip any losses from it. I worked for a valve manufacturer who had a plant in China. The guys I was communicating with were very smart, but neither of us could properly communicate technically. Drawings and pictures cut right through the fog, we all understand when we see it.

My h75 has been working exceptionally well and it's a joy . However few days ago I noticed a very rough andnintsable start، idling and lack of throttle response. As usual I checked the carb , and intakes , compression and spark plugs to make sure they are all fine and they seemed to.
What I noticed on the spark plugs were this black shiny deposit and I didn't think much of it as it wasn't a soot or wet, until I during my tests I replaced the plugs and engine worked perfectly again.

I'm surprised on how short lived the plugs were, specially as I replaced the PK ones with RCEXl which has been working amazingly and without the black deposit on my R90s .

Has anyone else with H75 noticed low life span of plugs ? I must add I'm using mixture of coleman fuel and Lucas oil treatment which is same as MMO. I believe the carb setting is correct . I do noticed that it's quite hard to get all 4 cylinders to run on low idle . Could this be caused by over heating of spark plugs ?

Odd thing is it's not the typical soot. It's a thin layer of baked on black shiny stuff. I am suspecting the Lucas oil added got overheated and caused this. I ran the engine around 20 times and only thing came up was this. Had to spent a good amount on adjusting valves on all cylinders first but it runs beautifully