GO 21 Engine running hot!

[Langy]

I've a GO .21 engine that I've managed to put through about half a gallon so far. This was to replace my older standard Hyper 7 engine that got cooked.

The engine seems to be running far too hot for my liking at the moment, just running it around the garden and i'm already getting 280+, so I've soon stopped as I don;t want to do the same with this engine as the last one.

The main needle is only in about half a turn from the factory flush settings and seems still to be running fairly rich.

I'm running on Byron Gen 2 25% fuel that I have always used.

I'm using a GO N3 Plug which I believe to be a hot one.

I also have a new McCoy MC-9 what I used for my old Hyper 7 engine, would this be too cold or would this sort out my issue?

I would rather run the engine a little more rich and cooler than possibly cook it like the last one.

Thanks in advance for your help.

Langy

[Langy]

Oh and I forgot to mention that whilst finishing the run in today I managed to smash the pipe.

The small outlet pipe got pushed right back so I have managed to put it back in place but it now needs replacing as it wont take much to knock it off.

Not sure if this would effect the engine temp?

Langy

[chrisknights]

check for air leaks m8

[Stormbringer]

try the mc9 plug

if your running a hot plug the engine will run hotter

[Mr Terminator]

Go engines run on the hot side anyway but all engines will run at higher temps during the break in,the tighter they are,the hotter they get.Once it's been broken in and loosened up fully,the temps should settle down,all the Go engines i've had in the past ran comfortably at around 265F-270F once they've settled in properly,I used Go No3 on break in.Do check the carb inlet and backplate for airleaks too,just as a precaution,as soon as you can,try a medium/cold plug and see if that makes any difference and try longer runs somewhere you can open the engine up to maximise air flow,pottering a race engine around a garden at what can only be slow speeds will cause heat build up also....

[dja1000]

Have you read and understood the GO engine tuning guide? Both of mines run hot, .25 especially so.

http://go-racing.vpweb.co.nz/Tech-Tips.html

[grovehead]

Have you read and understood the GO engine tuning guide? Both of mines run hot, .25 especially so.

http://go-racing.vpw.../Tech-Tips.html

hi i have a go 25 and ive been looking for the operating temp but its not on that link you put up

its a go 25 standard engine not the gx

[dja1000]

hit submit twice i think?

Edited July 18, 2010 by dja1000

[dja1000]

hi i have a go 25 and ive been looking for the operating temp but its not on that link you put up

its a go 25 standard engine not the gx

After a lot of trawling when i got my engine i came to the following answers:-

Some of the Sport and the older engines have long LSN, or semi long LSN for some. These are identified by taking off the air filter and looking at the length of the LSN, throughout the throttle range it should still be in the jet, at WOT it may just leave the jet (that is the semi long needles i belive) .

Both of these types use the above guide except (quoted from an email from Shane at GO.nz) the sport engines if they suffer from lean bog at the bottom of the tank you richen the LSN a touch.

In my experience it takes very little adjustment to get a tune and 1/12th of turn on the HSN makes a big difference, especially to the heat.

I also belive the Ishima engines are the same??

Edited July 18, 2010 by dja1000

[badger906]

Go. engines are quite hard to tune, the smallest tweak of a needle has a huge effect on them.

They do run on the hotside regardless.

Air leaks around the carb seem to be common (well iv had one and so has my brother).

[dja1000]

Go. engines are quite hard to tune, the smallest tweak of a needle has a huge effect on them.

They do run on the hotside regardless.

Air leaks around the carb seem to be common (well iv had one and so has my brother).

I would second the carb bit mine leaked around the pinch bolt

[chrisknights]

Went out today for a bash and done some temperture checks on my GO.28 with a medium plug NO4 fastrax which i have had in there for about 3 to 4 months now and temperatures reached 270f after long runs up and down the field , then started doing jumps so it was off and on the throttle and tempertures were around 250f and it sounds and runs sweet and smokes well ,

i have tryed other plugs mccoy no9 cold plug and my engine eat that in about 3 tanks and the os plug and it was the same so stuck back in the NO4 plug and it loves it ,

i sealed around the carb and where the pinch bolts are as well as the back plate as temperatures reach 320 f and i shut it off straight away but like i have said it runs sweet now

[Langy]

Thnaks for all the replies guys, most appreciated lots of different things to think about.

Firstly I did try the McCoy MC9 plug today and it was a little groggy in getting started and seemed very rich at the low revs, I didn't want to adjust anything if it ran so I could try and compare the engine temps.

I only mamanged to run one tank through before the neighbours came home (don't get on with then so don;t need to upset them anymore) but checking the engine temp it did not even reach 200F. However I did notice that when I put the car away the 90 degree pipe that comes out of the engine (for the exhaust) did hit near 300F, very wierd I thought. Also my exhaust is in a pretty bad way after smashing the small pipe yesterday as there are now holes either side of it spitting out the fuel right over the front wheel.

Yesterday I also noticed that the rubber gasket (apologies for wrong terminology) mounted on the engine for the exhaust had a tear in it. This was one that I fitted from my Hyper 7 engine as teh exhaust fitted more snug. So I replaced it with the original one and the exhaust does not seem to be a very tight fit over it. Not sure if this will make any difference.

Thanks dja I have had a look at the GO site and seen

Going on experiance, you shouldn't need to lean the HSN any more than 1/8 of turn in from the factory setting of flush for peak performance (although differing fuel and pipe choice may dictate otherwise).

Think I have the needle in at least half a turn. With only runnign the engine at such low power there has always been plenty of smoke so thought I was far from the tuning spec of the HSN. I will put this flush again and see how the engine runs on temps then. So used to having to wind in the HSN a bit to start with and then fine tune the LSN.

Looks like I will also have to try the air leak test at some point as well. Not sure how the back plate is but this is a non pull start engine so guess there must be a back plate there somewhere to check.

On the exhaust, does anyone know how what sort of temp should be going out of teh final small pipe? I did have a thought last night that I could possibly solder up the holes if the temp is below the engine running temp. Would need to do a melting temp test on the solde I have first.

Anymore advice most appreciated.

God this engine is hard work, all I want is a reliable engine without anymore expense and hassle so I can just go to my local track for 5 min races. I know I'm going to be far from the best but would like to compete with the bottom end of the people.

Langy