Bodge

Here's a piccie of my JEN 56 with AJ's diesel head on and a 7mm MVVS carb. I never had any success with this engine as a glow (would not throttle up cleanly) so perhaps it will work better as a diesel. Just thinking about a model for it now...

Also shown is a diesel head for an ASP 12. The ASP 12 is a very small, light engine - I just ordered it along with the head, but I sent it straight back as a bearing felt notchy. I plan to use its replacement in electric models converted to diesel. Will be nice to take with me when I'm out "walking the dog".

The 56 is an ABC engine: if it still refuses to work properly (I can't see that now) I'll use the ringed version I have, which is also not very good at responding to the throttle - as a glow, anyway.

Can't wait to hear them running - it's been many years (control line days) since I've run any diesels.

AMB

Bodge I remember ! had a carb problem with one of my Jen56s. I swapped carbs and end of problem and got an other carb from Just Engines and it worked fine never did figure out the first one**. The ASP is going to go like a striped ape have the conversion

** Actually I did (Just remembered ) months later pulled the carb apart and there was a piece of lint under the fuel nipple in the carb
now is fine/

On the carb repsonse issue put a small piece of fuel tubing on the carb , this is done easier with the carb off the engine close the low
speed (idle) screw in while blowing thru the tubing with the throttle barrel closed when you can no longer get a hiss out of the carb open the screw 1/2 to 3/4 turn then put it back on the engine and give it a try you should be quite close and get a decent response
then go from there on your final I just checked mine and it is exactly 7 1/2 turns out from all the way in and closed martin

and by the way the diesel head reads 47 on it do you have the right engine pictured ?? so now we know you have a 47 and 56 martin

Bodge

Martin,

You are right - it does show 47, but what you can't see because of the reflection is the 47/56. I guess the the difference in bore size has no effect on the head change...

Regarding the throttling problem - failing to throttle up without flooding off - this fault is apparent to some extent on both 56s and, despite trying everything I know, have not been able to cure it on the ABC. The ringed has only 15 minutes on it - it seems better than the ABC so far, but there is still an indication of the fault when opening the throttle. Hence the MVVS carb. The carb is a little small for glow at 7mm but we'll see how it works on the JEN diesel. MVVS make great carbs - the ones on my 91 and 49 work faultlessly.

One of the first things I did when the ABC was showing problems was to strip the carb - I did remove three twists of brass swarf out of the carb, but it did not make much difference. Even changing the carb to an old OS 45FSR unit that fitted did not cure the problem. I think they were meant to run as diesels...

I am going to try a larger MVVS carb on the ringed glow 56, though.

I'm looking forward to running the 12 - it's a very nicely made engine (despite the bearing problem). I am thinking about an electric Ultra Stick for it - seems about the right sort of size and the engine is accessible to get me into running diesels again.

AMB

Just a guess you may need a different plug one that hold the heat a little better, but this of course becomes a non-issue as diesel.
Interesting fact the ASP 12,15,21 were one offs as a test, they do so well as diesel now production units
I did fit an MVVS carb to my PAW 40 twin BB a few years ago very good response compared to the old stock PAW one martin