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Posted: Tue Feb 23, 2010 2:14 pm
by JanBros
KwakOn wrote:=D> =D>
like the look.
surely the Y section would 'silence' quite a bit of the sting as well. Its the first split in a 2T exhuast that I have seen. Hope it works for you.
the 2 small tubes have about the same surface as the big one (they are only 0.4mm to small in diameter to be exactly the same), so guess there won't be much silencing overthere
Posted: Wed Apr 14, 2010 10:32 pm
by JanBros
put the engine back together. state was ok, but clearly it has had it's suffering in it's life (it appears to be one off the first waterboilers, so it's about 25 years old
). just fitted new seals and bearrings on the cranck and left the rest as is.
and then tried to start it for the first time
](./images/smilies/eusa_wall.gif "Brick wall")
she replied with
I asked her that, if I really did my best, she would please at least turn her cranck about 360° ... [-o<
she answered
how the bloody hell do you start these beasts
. after about 30-40-50 attempts, my home-made kick splindle took me out off my misery by giving up
thinck I'll be going for plan B now. Still have an industrial h***a GX160 engine, will transform that into one off those "MotoGP-engine starters"
Posted: Thu Apr 15, 2010 10:55 am
by KwakOn
JanBros wrote:how the bloody hell do you start these beasts
sorry, dont know.
I guess you dont want to bump start it (push), could be quite a handful. I have a 600 single (4T
) which I couldn't bump for a while (when batt was flat) - until I tried with the throttle open a bit
it is probly a bit softer than a 5hundie.
Posted: Thu Apr 15, 2010 9:57 pm
by falconman
The procedure for starting a big bore single is to press on the kicker to set piston position to TDC (or just after). Then jump in the air and use all your weight to kick it through as quickly as you can. If you still can't get it to pass TDC again you might have too much oil in the top end raising the comp too much. I had to install a comp release in my F9A after I rebuilt the top end on it. After a couple hours of run time it starts alot easier.
Posted: Thu Apr 15, 2010 10:58 pm
by JanBros
falconman wrote:The procedure for starting a big bore single is to press on the kicker to set piston position to TDC (or just after). Then jump in the air and use all your weight to kick it through as quickly as you can. If you still can't get it to pass TDC again you might have too much oil in the top end raising the comp too much. I had to install a comp release in my F9A after I rebuilt the top end on it. After a couple hours of run time it starts alot easier.
I saw that once on a forum, don't remember which one though. was planning on doing a search on that tonight.
downside on having it started with an outside engine, is you can't restart the bike if it stalls or something happens
Posted: Thu Apr 15, 2010 11:19 pm
by falconman
My experience has been once you have got it running it will start easier the next time. It's just that first fire up that's hard.
Posted: Sat Apr 17, 2010 12:49 am
by JanBros
found everything I needed to know on KXriders.com
drilled a hole from a stud into the combustion chamber :
made a special nut with an extra hole to let the air pass through :
and just bolt it all together :
before taking the head off, I wanted to measure the squish .... but couldn't
, it was more than my soldering was thick (2mm)
I can't imagine how hard it must be to kick a heavily tuned high compression 500
so anyway, milled some off the head, and while I was at it, put an O-ring in it, so no more need for head gaskets
squish is now still a very safe 1.5mm (1.3 appears to be common for standard engine).
now I have to remake my kick-shaft to have another go at bringing it to life
Posted: Sat Apr 17, 2010 8:59 pm
by KwakOn
=D>
good job, I was going to suggest fitting a decompressor like large chainsaws have. some big singles have automatic ones I think, linked in with kickstart
Posted: Thu Apr 22, 2010 12:14 pm
by Sheik Yerbouti
Good work there Jan, but what compression ratio do you have after taking half a mil off the head?
Posted: Thu Apr 22, 2010 10:40 pm
by JanBros
Sheik Yerbouti wrote:Good work there Jan, but what compression ratio do you have after taking half a mil off the head?
asked some questions about htis on KX-riders.com, but no aswer yet.
even with the decompression, I find it incredibly dificult to get this motor kicked over
is it me
or the engine ?
volume of the combustion chamber is about 32.7 ml (including complete sparkplug hole). shape off the head is completly standard, squish is 1.5mm now which is still on the very safe side I recon ? piston is at TDC even with the top surface off the cylinder.
are these normal figuers ? or is there anything done to the engine that it's compression is on the high side ? cylinder has a steel liner, so maybe they took off a bit at the top to get an even surface ?
Posted: Thu Apr 22, 2010 11:44 pm
by Sheik Yerbouti
or is there anything done to the engine that it's compression is on the high side ?
I think somebody skimmed the head
Dunno mate, my DT400 has a decompressor widget too, but it's a little way down the barrel not in the combustion chamber. Is your hole big enough to let the pressure out? Have you booked yourself into a local gym yet?
Posted: Fri Apr 23, 2010 11:09 pm
by JanBros
Sheik Yerbouti wrote:or is there anything done to the engine that it's compression is on the high side ?
I think somebody skimmed the head
It was I ... /color]
Dunno mate, my DT400 has a decompressor widget too, but it's a little way down the barrel not in the combustion chamber. Is your hole big enough to let the pressure out? Have you booked yourself into a local gym yet?
without the valve it's still dificult, but ok. with the valve I have to jump it. hole in the head is 2.5mm, normaly they (KXriders.com) make a 2mm hole.
but there are videos off people starting it while just sitting on the seat ... unless they have a 125 build in there K5
Posted: Sat Apr 24, 2010 6:07 am
by iain250
cracking job jan - stick a you tube link on when you get her running ive got to hear that monster
iain.
Posted: Mon May 03, 2010 10:12 pm
by jonnykr1
strange project, i use to have a kx500 the same as what your engines from (first of the liquid cooled, pre power valve, B1 model iirc), aside from being a total Lovely Chap to kick start, they vibrate so much its unreal.
i could only ride for about 15-20 Min's before my hands physically had pure pins and needles with zero feeling for anything left in them.
they are possible to bump start, however they require two people pushing and a 20 stone mate on the bike lol, on tarmac only ofc
Posted: Mon May 03, 2010 10:48 pm
by JanBros
jonnykr1 wrote:strange project, i use to have a kx500 the same as what your engines from (first of the liquid cooled, pre power valve, B1 model iirc), aside from being a total Lovely Chap to kick start, they vibrate so much its unreal.
i could only ride for about 15-20 Min's before my hands physically had pure pins and needles with zero feeling for anything left in them.
they are possible to bump start, however they require two people pushing and a 20 stone mate on the bike lol, on tarmac only ofc
was your engine mounted fix or in rubbers ?