motor getting **** HOT!

Racing a Seagull? Got an event planned? Race announcements, results, mods and the boats here

Moderators: John@sos, charlesp, Charles uk, RickUK, Petergalileo

Horsley-Anarak
Posts: 2718
Joined: Thu Aug 07, 2008 8:42 pm
Location: Surrey

Re: motor getting **** HOT!

Post by Horsley-Anarak » Wed Nov 18, 2015 5:39 pm

Collector Inspector wrote: The topic is dead and thank you still.
Not sure why the topic is dead Bruce, steep learning curve here, I am sure Jon will have had the one hour phone call, to help him out.

Only one ruined crankcase so far :lol:

H A

headdownarseup
Posts: 2485
Joined: Thu Apr 04, 2013 2:26 pm
Location: bristol

Re: motor getting **** HOT!

Post by headdownarseup » Wed Nov 18, 2015 8:30 pm

Not "dead", just going over some things!

Much learned along the way, the same mistakes WILL NOT be made again..... (as i'm slowly running out of crankcases :shock: :lol: :lol: :lol: )

My mind is more at ease now, i have a direction or 2 in which to go?

Baby steps and all that.

All good though

And by the way, thanks Chas for your help and advice. Makes more sense now :P

Jon

Adrian Dale
Posts: 758
Joined: Wed Apr 16, 2014 7:58 am
Location: Tasmania, Australia

Re: motor getting **** HOT!

Post by Adrian Dale » Wed Nov 18, 2015 10:05 pm

we are keen to hear the updates and progress jon. By the time I get back to the UK in May I expect you to be running rings round me on the River!!

AJ

headdownarseup
Posts: 2485
Joined: Thu Apr 04, 2013 2:26 pm
Location: bristol

Re: motor getting **** HOT!

Post by headdownarseup » Thu Nov 19, 2015 8:42 pm

Steady on A-J, i'm still trying to get my head around the basics, let alone "tweeking" anything yet :oops:

After my first attempt at (ahem) modifying shall we say, it didn't quite have the desired results :oops:

Moving swiftly on then.... :roll:
the mark 2 version is currently at the measuring and evaluating stage. Now i know which direction i want to go with this i can start making enquiries into getting bits and bobs "trimmed professionally" and CAREFULLY....

I'm working on the theory of less is more.
I have read and re-read different chapters in various books and come to my own conclusions on some things. Others out there will have their own thoughts too.


FRICTION..... often the scurge of 2 stroke engines as it can sap power. After my last attempt, friction was the killer factor that "cooked" the crank. Mind you, the crankcases being completely out of alignment didn't help either.
So the "mark 2" has a (rather sloppy fit) replacement set of second hand cases. Loads of crank end float as you'd expect (around 1-1.5mm as best as i can measure) sounds a lot doesn't it? I'm not that bothered, as long as nothing spinning within isn't binding up to provide the heat then that'll do for me.
Then there's the piston. Perhaps the guts of it all as it has to do all the hard work. Again, not a tight fit.... more on the loose side. (less is more)
Measurements on the port timing seem to be within specs (after conversations with the "master") although still a bit of room for improvement.

Baby steps all the way.
A little here, a little there, then test.


As for running rings, lets just hope for a comfortable mid field runner.

All good though, learning lots along the way.

Jon

headdownarseup
Posts: 2485
Joined: Thu Apr 04, 2013 2:26 pm
Location: bristol

Re: motor getting **** HOT!

Post by headdownarseup » Mon Nov 30, 2015 10:18 pm

Progress report:

Crankcases are now "up to snuff" with a decent pair of bushes.
Internal volume has been decreased somewhat by "stuffing", but perhaps more importantly the internals have been given ample room in which to spin without any snagging or binding. Plenty of room for improvement later on if i need it.
The transfer port is now carefully matched to the cylinder.

The cylinder is nearly ready for it's "trim". (professionally this time :lol: ) not making that mistake again!
Exhaust port is full of junk still, so this will need a bit more work yet to get things smooth
All in all, looking promising.

Pics to follow when the cylinder is back in my hands again.

Jon

headdownarseup
Posts: 2485
Joined: Thu Apr 04, 2013 2:26 pm
Location: bristol

Re: motor getting **** HOT!

Post by headdownarseup » Tue Dec 08, 2015 9:52 pm

Well, ok. I've had a little setback. Nothing bad. Just having to wait till the new year before the cylinder gets a "trim".

In the meantime i've been working on the crankcases. Everything inside is shite and briney and re-assembled. While i still have the cylinder i'm double checking all the ports again for straightness and cleanliness. Also the fit and finish which at times has left a lot to the imagination.

I've changed tack with the cylinder head too. I found the "one" you lot seem to like. After a bit of repair work it's looking pretty good now.

Had a rethink on the ignition too.
CDI is what i've decided on after a "tweek" here and there, that is now looking the canines under- carriage. Superb spark from it :P .

Lower unit is almost ready to go. As is the prop.
I have an anti cav plate roughed out in some sheet ally when the mood takes me. Might hold off on this for a while until i've done some river testing with the motor in the new year. See how it goes i guess.

I'm thinking on a colour scheme for this "thing". As it's a bitsa anyway, it doesn't really matter too much.
I'm thinking very patriotic. Red, White and blue! Maybe a union jack on the fuel tank? (quite time consuming and takes a lot of masking tape but i can do this sort of paintwork, might be a giggle, might get some strange looks but what the hey)

All thoughts and suggestions welcomed gents

More to come later when it's back together. :P


Jon

headdownarseup
Posts: 2485
Joined: Thu Apr 04, 2013 2:26 pm
Location: bristol

Re: motor getting **** HOT!

Post by headdownarseup » Wed Feb 24, 2016 7:47 pm

Nothing much happening with this at the moment as most of my attention is diverted with preparing 2 motors for the "Canal Run" later this year.
Ignition system is ready to go. Lower unit all buttoned up now and looking SWEEEEET.
Red White and Blue will be the colour scheme i've chosen for this "thing". Something a bit special for the tank too.
As for the powerhead, things are still as i left it (in bits) but with a more positive direction in which to head.
I think it will turn out quite well, but you never can tell until after some testing.

More coming later on.


Jon

Post Reply