Author Topic: Modification of commercial Chinese Hit & Miss engines.  (Read 3166 times)

Offline Bruno Mueller

  • Full Member
  • ****
  • Posts: 152
    • My Homepage
Modification of commercial Chinese Hit & Miss engines.
« on: October 14, 2024, 03:11:18 PM »
I have some Chinese Hi & Miss motors that I have modified a little.
Firstly my first engine.
An Enjomor 6 cc Hit & Miss engine.
The problem with this engine is the inertia of the intermittent control. The tension spring of the centrifugal weight switch cannot be adjusted. As a result, the engine turns too quickly and the cut-off control works too slowly.
To dampen the spring a little, I made a bridge over the breaker lever with an adjusting screw and a small spring that works against the centrifugal weight spring. This reduces the speed a little and relieves the centrifugal weights.
I also fitted a shut-off device to the petrol tank. Previously, the tank ran empty via the carburettor.
I fitted a roller to make it easier to start the motor. The tapered bushes of the wheel mounting could not be loosened afterwards. That's why I put forcing screws in the flange of the bushes.
I replaced the original oil cup for cylinder lubrication with a sight oiler.

You can also see the engines on my Youtube channel.
https://www.youtube.com/@Jailguzzi
« Last Edit: October 14, 2024, 04:23:04 PM by Bruno Mueller »
http://mueller-bruno.de/  http://www.bosch-combi.de/   https://www.youtube.com/@Jailguzzi
Whoever talks shit about me behind my back is in the best position to lick my ass. 
Greetings from the southwest of Germany.

Offline Bruno Mueller

  • Full Member
  • ****
  • Posts: 152
    • My Homepage
Re: Modification of commercial Chinese Hit & Miss engines.
« Reply #1 on: October 14, 2024, 03:33:55 PM »
The next engine in the series is an "Eachine Et 6".
I have mounted this motor on a sled.
The problem with the leaking petrol tank also existed with this engine.
I made a new petrol tank with a shut-off facility.
I also fitted a sight oiler for the cylinder. In the original, the crankshaft runs in needle bearings, but these have a lot of clearance on their running surface. I have replaced the needle bearings with suitable sintered bronze bushes. I provided the bushes with an outer ring groove and a lubrication hole. I cut threaded holes in the bearing caps and fitted oil cups. Now the engine runs nice and smooth and the crankshaft no longer jumps in its bearings.
I moved the exhaust to the top.
« Last Edit: October 14, 2024, 03:45:03 PM by Bruno Mueller »
http://mueller-bruno.de/  http://www.bosch-combi.de/   https://www.youtube.com/@Jailguzzi
Whoever talks shit about me behind my back is in the best position to lick my ass. 
Greetings from the southwest of Germany.

Offline Bruno Mueller

  • Full Member
  • ****
  • Posts: 152
    • My Homepage
Re: Modification of commercial Chinese Hit & Miss engines.
« Reply #2 on: October 14, 2024, 03:55:31 PM »
The third engine in my collection is a Retrol (Musa) HM 01. This engine came to me as a single-part kit. Assembly was very easy thanks to the excellent instructions.
Setting the ignition timing proved to be very difficult with the original contacts. I replaced these bronze plates with a microswitch and a holder for an adjusting screw.
The adjustment was then very easy.
http://mueller-bruno.de/  http://www.bosch-combi.de/   https://www.youtube.com/@Jailguzzi
Whoever talks shit about me behind my back is in the best position to lick my ass. 
Greetings from the southwest of Germany.

Offline Admiral_dk

  • Full Member
  • *****
  • Posts: 4055
  • Søften - Denmark
Re: Modification of commercial Chinese Hit & Miss engines.
« Reply #3 on: October 14, 2024, 06:23:49 PM »
Nice modifications Bruno  :ThumbsUp:

Are you otherwise happy with them or is there more that should be modified ?

Per          :cheers:

Offline Bruno Mueller

  • Full Member
  • ****
  • Posts: 152
    • My Homepage
Re: Modification of commercial Chinese Hit & Miss engines.
« Reply #4 on: October 14, 2024, 07:25:18 PM »
In the meantime, I have replaced all the piston rings with Viton (FKM) rings from domestic production.
The Chinese rings did not last long.

The one or other engine has too little or no flywheel balancing and bounces around on the table.

Otherwise the engines run perfectly.
« Last Edit: October 14, 2024, 07:28:49 PM by Bruno Mueller »
http://mueller-bruno.de/  http://www.bosch-combi.de/   https://www.youtube.com/@Jailguzzi
Whoever talks shit about me behind my back is in the best position to lick my ass. 
Greetings from the southwest of Germany.

Offline Bruno Mueller

  • Full Member
  • ****
  • Posts: 152
    • My Homepage
Re: Modification of commercial Chinese Hit & Miss engines.
« Reply #5 on: November 12, 2024, 03:27:53 PM »
I smoked the ignition electronics on the Retrol Musa HM 01. No, it didn't smoke, but I had no ignition spark.
As a precaution, I bought replacement electronics a few weeks ago. After replacing the ignition box, the device is working again.
Everything in the ignition box is filled with potting compound, so nothing can be repaired.
http://mueller-bruno.de/  http://www.bosch-combi.de/   https://www.youtube.com/@Jailguzzi
Whoever talks shit about me behind my back is in the best position to lick my ass. 
Greetings from the southwest of Germany.

Offline Admiral_dk

  • Full Member
  • *****
  • Posts: 4055
  • Søften - Denmark
Re: Modification of commercial Chinese Hit & Miss engines.
« Reply #6 on: November 13, 2024, 06:32:55 AM »
That is annoying  :zap:

The potting can usually be removed using heat ....
The compound usually breaks down around 150-160 degrees centigrade ....
I use a temperature controlled hot-air gun and small screwdriver / tweezers, to gently lift the compound (epoxy) away.

Per        :cheers:

 

SimplePortal 2.3.5 © 2008-2012, SimplePortal