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MOKI 75cc
Posted: March 4th, 2015, 1:00 pm
by richard armstrong
Hi all
i manage to get hold of a moki 76cc engine for a small some of cash?
just wondering what size airframe it would fit?
Re: MOKI 76cc
Posted: March 4th, 2015, 7:13 pm
by Ken Bones
Doorstop.
Re: MOKI 76cc
Posted: March 4th, 2015, 7:34 pm
by richard armstrong
Now thats Funny
But lets get serious for a sec
what scale would this suit?
came with 26 x 10 prop,
Re: MOKI 76cc
Posted: March 4th, 2015, 11:42 pm
by ian redshaw
Ken is being more than serious here, I bought a model with a Moki 75 in and it was the nastiest running engine I have ever had. Very bad for overheating and vibration, could only get it reliable if detuned to about 60%. I would only fit it on an uncowled airframe just to keep an eye on it!!!
Ian.
Re: MOKI 76cc
Posted: March 5th, 2015, 12:51 am
by richard armstrong
thanks for the advice
i get the feeling that certain moki's are not like or just had bad times,
i will bench run first and set up, just got to drill out the prop
i will video it as well running?
the only thing which size of airframe would you fit it to
Wingspan and/or scale some ideas please
i was thing a large scale harvard at6 texan
Re: MOKI 76cc
Posted: March 5th, 2015, 10:05 am
by Bob Thompson1894
Richard, read Ians post again and then look at a Harvard......
Re: MOKI 76cc
Posted: March 5th, 2015, 10:47 am
by richard armstrong
i read red the post bob, and look at the ziroli at6 texan
the cowl is semi open cowl with a lol of airflow requires a 62cc @100in but 75cc will give it a little kick
the issues of cooling might be an issue, but the airframe the moki came from was enclosed, Colin the previous owner had no issues, will have to test it first, as he sent it tested and run with a very nice pitts twin exhaust,
like i said i will have to bench test first, before committing airframe suicide
if any one wants to swap for brand new z62 with cdi, or a dle 60/eme 61cc with pitts
i will discuss
Re: MOKI 76cc
Posted: March 5th, 2015, 1:08 pm
by Rob Buckley
What airframe did it come out of? It'll fly one about that big (providing it flew!)
Re: MOKI 75cc
Posted: March 5th, 2015, 4:28 pm
by richard armstrong
quote from previous owner - COLIN
"The Moki was in a yak type of airframe.. ARTF.. had it a while but didn’t appeal to me.. aerobatics aren’t my thing! More into scale!.. I was keeping it for the ¼ scale P51 but the guy who bought it had a DA 85 so did not take it"
Re: MOKI 75cc
Posted: March 5th, 2015, 8:04 pm
by paul needham
You've got a greenly haven't you Richard ? Hang it on the front of that if anything.
Re: MOKI 75cc
Posted: March 5th, 2015, 8:35 pm
by richard armstrong
paul needham wrote:You've got a greenly haven't you Richard ? Hang it on the front of that if anything.
greenly part built so yea that's an idea i am building the 50-70cc version but at present on the shelf
need to finish other projects like the T180, the 240 is still in its box,
i am on the look out for a high wing, cessna style PNF airframe
Re: MOKI 75cc
Posted: March 5th, 2015, 8:39 pm
by Ken Bones
The only airframe I would put one into is a glider, as ballast!
Re: MOKI 75cc
Posted: March 5th, 2015, 8:43 pm
by richard armstrong
Ken Bones wrote:The only airframe I would put one into is a glider, as ballast!
have to LOL at that
nice one
Re: MOKI 75cc
Posted: March 9th, 2015, 6:00 pm
by Andy Macqueen
Here Here.....definately worst engine ive ever tried, as ian says bad for overheating due to design and very small cooling fins, rings tend to sieze up from heat,carb was always in need of tuning to get half decent power,i tried two and worst bit was i bought a second one.....!
Re: MOKI 75cc
Posted: March 9th, 2015, 6:19 pm
by richard armstrong
Re: MOKI 75cc
Posted: March 9th, 2015, 9:26 pm
by Andy Macqueen
just put it in something that will glide really well when it cuts out.........
Re: MOKI 75cc
Posted: March 9th, 2015, 11:33 pm
by Glenn Masters
Hang on . . all might not be lost - I have had experience trying to get one of these motors to behave itself, and after much gnashing of teeth I found the culprit to be a design shortcoming in that Moki, in their wisdom decided to stick the ignition pick-up on the back of the crankcase. The ignition magnet is set into the rear of the crankshaft and the pick-up sticks through the rear case to sense the pulse . . The problem is that the two are perilously close together and any crankshaft end float causes the pick-up to be shoved out of its position and then it starts to let air in (especially if a starter is used) This causes the erratic running and overheating. I found the solution was to bury the pick-up in good quality silicone to seal things up. Good ducting is a must as it has indeed got meagre finning, but I did get mine to run ok. It'll never be a 3W though !
Re: MOKI 75cc
Posted: March 10th, 2015, 12:35 am
by richard armstrong
Glenn Masters wrote:Hang on . . all might not be lost - I have had experience trying to get one of these motors to behave itself, and after much gnashing of teeth I found the culprit to be a design shortcoming in that Moki, in their wisdom decided to stick the ignition pick-up on the back of the crankcase. The ignition magnet is set into the rear of the crankshaft and the pick-up sticks through the rear case to sense the pulse . . The problem is that the two are perilously close together and any crankshaft end float causes the pick-up to be shoved out of its position and then it starts to let air in (especially if a starter is used) This causes the erratic running and overheating. I found the solution was to bury the pick-up in good quality silicone to seal things up. Good ducting is a must as it has indeed got meagre finning, but I did get mine to run ok. It'll never be a 3W though !
thanks glenn
any chance i could give this to you to solve, the timing cable (grey, hall sensor type,) comes out of the back but no sealant, or can this be done at the field
i know it will never be a 3w, but i do want it to run right and not have to fart about with it set it up and leave it, and only tweak it occasionally,
the airframe i had in mind is a Cessna 182, 26%, when i brought it?
Re: MOKI 75cc
Posted: March 10th, 2015, 4:30 pm
by Glenn Masters
Sorry - cant get time on my own modelling projects just now. Try it first - it might be ok !
Re: MOKI 75cc
Posted: March 10th, 2015, 7:42 pm
by paul hughes
you walked into that one Glenn.
well dodged! lol