Running the engine

This part deals with preparing to run the engine for the first time an early runs of the engine.

The engine was completed as far as necessary to allow a firing up to be tried.

The result was all a bit hit and miss.

Several friends all gathered at 11:00 and established that fuel was being drawn into the carb so the ignition was attached and on the first pull over it popped and smoked but nothing more than one fire.

Then during the next 90 minutes everything was tried and we had a second firing of about 5 ignition strokes and then nothing.

After lunch one friend came back round and we fitted the third piston ring with careful attention to width and depth AND the fact the the rings have a top and a bottom which I did not realise ... was taken in to account and properly fitted. This gave much more compression than when we left it before lunch.

Then on the first pull again engine did run for 12 revolutions and the stopped and then another pull and it fired and nearly got up to speed but finally petered to a stop.

That was a bit of luck as I then noticed that the crank shaft has moved ... The Loctite 603 had let go ... So the repair was made by reapplying 603 but the crank will need to come out and I will be pinning it in all 4 places to stop that ever happening again ...

We also found at that too much fuel was going into the engine ...

There is no disappointment on my part for had it run without problems one would not have to work out why will it not run and learn nothing ... Even motor engineer friend and all his experience is at a loss as to why is does fire but then does not continue to fire....

We have spark, fuel, compression but that is it ...

This does away with the throttle and .. A hand can act as the choke.

So I am working on that !!!

I have pinned the crank and all is well as it went back together easily .. the key ways do not align but that does not matter !!!!

I will check the tension of the spring but at the moment the engine has not reached speed to throw the MISS into gear... it is fun waiting ...

I wish I knew how to make a nice tapered jet screw !!!

I decided to make a starting handle reminiscent of the early cars. This was done and now the engine is ready to try again ...

The new carb was designed and made all but the non return valve.

More info on the carburettor section.

The engine fired up and ran until the fuel ran out. A refill was done and again the engine ran, in fact a bit over speed as the hit and miss needs adjustment as it did not cut in at all. The governor needs looking at carefully to find out why it does not operate. I have a suspicion it is too big a spring !!!

The speed was much too fast .. should be about 500 rpm ...

The governor did not operate as the spring was way to strong and other things stopped it operating .. I have eased down the shaft so that there is no drag on the shaft that is operated by the balls ... before it was a running fit .. now a sloppy fit !!!

The strip down revealed the following problems:-

1. that the main bearing had been moving in their seats - solution - the oilers have been made with M5 connection and this has been taken right into the bearings to prevent rotation.

2. the big end had slight end float - solution - a slight filing of the end piece take up the slack

3. the speed lever did not allow operate - solution - much lighter spring used and the minimum position noted

and also the good points:-

1. that the piston is as good as new

2. that there is no wear noticed on the gudgeon pins and end caps

3. the re-designed carb works very well.

When all is bolted back down and photos taken it will have another run ...

The engine was run again today ... A simple crank over to draw up fuel and then it started ... It was run for a few minutes and then suddenly stopped .. Reason the air intake had the choke lever close off the air flow.

The fly wheel grub screws had come loose and  loosen the flywheel themselves on the crank. with then all tightened up the engine ran again ... but a knocking started so engine was stopped. Flywheel loose again and also movement detected in the big end and the crank is starting to move ... MAJOR ATTENTION REQUIRED.

However all the improvements made ensured that the Hit and Miss action worked !!!!

Nearly a 20 minute run of the engine today. Starting was much easier but still a problem with the flywheels shaking the keyways  loose.

The engine has now been run for over 90 minutes and the original speed spring has been returned to use and now appears to be working very well as the engine is more and more run in.

I am still using a lot of oil as it is the cheapest part of the engine and the engine is not complaining.

The fuel tank still remains to be made.