Oh How Original Posted September 11, 2011 Share Posted September 11, 2011 My uncle has bought a Hyper 7 off eBay with a Mach 28 engine, it was advertised as running, but needed a starter box as the pullstart is broken, so anyway long story short, we managed to sort it out to get it actually running. Radio gear is all paired up and etc... Got it running, and it was spitting loads and loads of fuel out of the exhaust, so played with the tuning screws and set them back to factory settings, put the correct % fuel in as per the instructions, and it just won't run, it sits on tick over, and revs to a degree, but after 10-15 seconds it just splutters to a halt. It also seems to be running on tick over very very high. Anyone got any suggestions on what to do with it? Quote Link to comment Share on other sites More sharing options...
dazj10 Posted September 11, 2011 Share Posted September 11, 2011 sounds like it needs leaning out a bit mate, if its been set back to factory it will be running quite rich Quote Link to comment Share on other sites More sharing options...
Oh How Original Posted September 11, 2011 Author Share Posted September 11, 2011 sounds like it needs leaning out a bit mate, if its been set back to factory it will be running quite rich Tried that at 1/4 turn per try, then let it sit idling, it sits there, sounding like its going to stop, so you give it a tiny rev and it gives up. Quote Link to comment Share on other sites More sharing options...
Oh How Original Posted September 11, 2011 Author Share Posted September 11, 2011 Bare in mind we haven't just run it for like 10 minutes and got bored, it's been ran and been trying to tune it properly for a good 6-7 hours all day today. Quote Link to comment Share on other sites More sharing options...
dazj10 Posted September 11, 2011 Share Posted September 11, 2011 are you leaning the hsn or lsn ya need to get the hsn right before touching the lsn , but after each adjustment you need to drive it around instead of idling, are you getting the engine to a decent temp before tuning, i always do my tuning at 1/8 turns, takes a tad longer but it easier , Bare in mind we haven't just run it for like 10 minutes and got bored, it's been ran and been trying to tune it properly for a good 6-7 hours all day today. have you checked for air leaks Quote Link to comment Share on other sites More sharing options...
mrfodds Posted September 11, 2011 Share Posted September 11, 2011 Sounds to me like a very rich bottom end if it gives up as soon as you hit the throttle. Lean off (clockwise) 1/8th of a turn, let it run then bring back in. Let it idle for 10 seconds then accelerate. Once it starts accelerating from idle without cutting you can start to turn the idle down, tune the HSN for a good top end then re-check the LSN. Quote Link to comment Share on other sites More sharing options...
Oh How Original Posted September 11, 2011 Author Share Posted September 11, 2011 are you leaning the hsn or lsn ya need to get the hsn right before touching the lsn , but after each adjustment you need to drive it around instead of idling, are you getting the engine to a decent temp before tuning, i always do my tuning at 1/8 turns, takes a tad longer but it easier , have you checked for air leaks Yes checked for air leaks, as for getting it up to temp, yes it's up to temp, and as for driving it round, it won't drive round lol, it cuts out. Quote Link to comment Share on other sites More sharing options...
Monkey_Man Posted September 11, 2011 Share Posted September 11, 2011 put a nice new glowplug in first but does sound like its very very rich, to me it sounds like it will probably need leaning out the low speed by at least 1/4. i would try leaning it out a little at a time untill you can actually get it to pull away! Quote Link to comment Share on other sites More sharing options...
martin Posted September 11, 2011 Share Posted September 11, 2011 Once its struck up seems its mega rich adjust the hsn by leaning it don't put it on the floor try slowly applying throttle by blipping it adjust the hsn until it just starts to clear a bit, when rich the clutch engages and stalls the engine by having the wheels off the floor you don't get resistance and the engine can turn freely,once it is driveable and not stalling dial in the hsn then lsn, the mid range needle if its like the .21 set the screw to flush but totally remove the hsn body you will see the mid range needle hole this wants to be inline where the hsn goesl, this is where people go wrong with the mid range needle just because you have set it flush, it can be flush a 1/4 turn either way this is why you have to remove the hsn body to align the hole up properly mate. Quote Link to comment Share on other sites More sharing options...
b_hawk111 Posted September 11, 2011 Share Posted September 11, 2011 as above i would suggest, i tuned my hyper 7 first with wheels of the ground, then runnign around on the floor, it now is tuned beautifully and runs like a beast good luck with it, and try the pinch technique for the LSN, worked perfect for mine Quote Link to comment Share on other sites More sharing options...
pluto2010 Posted September 12, 2011 Share Posted September 12, 2011 Hi. It depends what it sounds like when it cuts out but as you have fuel coming out of exhaust i would say its too rich. I had to richen the low speed when on factory settings as it was so rich. I still then had to give it a push to get it going as the engine couldn't get it started and it would just stall. Quote Link to comment Share on other sites More sharing options...
Oh How Original Posted September 12, 2011 Author Share Posted September 12, 2011 Well it does move a tiny bit forwards, but then just cuts out. I'm also not sure if it helps or not. But I can't just hold the throttle at like 1/4 because as soon as you press the trigger, it revs to about 1/2 or just over 1/2 throttle. For some reason, not sure if that gives anyone any ideas? I personally don't think it's JUST a running rich problem. Otherwise it would still run, just very sluggishly. It's been leaned out quite a lot, and switched from 25% to 20%... So I don't think it's purely a running rich problem. Quote Link to comment Share on other sites More sharing options...
dazj10 Posted September 12, 2011 Share Posted September 12, 2011 (edited) Well it does move a tiny bit forwards, but then just cuts out. I'm also not sure if it helps or not. But I can't just hold the throttle at like 1/4 because as soon as you press the trigger, it revs to about 1/2 or just over 1/2 throttle. For some reason, not sure if that gives anyone any ideas? have you checked the carb gap is between 1 and 1.5mm when idling you havent toushed the mid range needle have you ? Edited September 12, 2011 by dazj10 Quote Link to comment Share on other sites More sharing options...
Oh How Original Posted September 12, 2011 Author Share Posted September 12, 2011 Yes the carb is set at around 1.2mm. And no the mid range has been left alone. Just trying to get it going first Quote Link to comment Share on other sites More sharing options...
missions1 Posted September 12, 2011 Share Posted September 12, 2011 i will get it sorted for ya mate Quote Link to comment Share on other sites More sharing options...
kingscott Posted September 12, 2011 Share Posted September 12, 2011 New glow plug (get a selection if possible) And What fuel you running? Get some quality Byron race fuel. Hope you get sorted. Quote Link to comment Share on other sites More sharing options...
Oh How Original Posted September 12, 2011 Author Share Posted September 12, 2011 New glow plug (get a selection if possible) And What fuel you running? Get some quality Byron race fuel. Hope you get sorted. Never liked Byron fuel, I always use Optifuel, I just find all my nitros run better on it. Quote Link to comment Share on other sites More sharing options...
pluto2010 Posted September 12, 2011 Share Posted September 12, 2011 (edited) You shouldnt really go down in nitro %. Not sure how badly it affects anything but apparently when you go up in nitro you should do a quick break in. Do the revs raise when it cuts out or does it just stop? If you take the wheels of the ground do the wheels turn at idle? Also when the wheels are off the ground try just a tiny bit of throttle, by tiny i mean very small, if the wheels start turning then increase the throttle slowly to increase speed. IDont rev it too much off the floor but just keep an eye on the exhaust, if you can get the wheels turning and there i lots of fuel coming out of the exhaust then you are mega rich and may have to lean the low speed. Are you using the settings found in this manual? https://viewer.zoho....220-MACH-28.pdf The reason i ask is because the sheet that came with my hyper 7 21 was wrong so im just wondering if the sheet that comers with the 28 is wrong also. 2 turns from closed for LSN and 3.5 turns from closed for HSN Edited September 12, 2011 by pluto2010 Quote Link to comment Share on other sites More sharing options...
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