Thunder Tiger Mta4 Sledgehammer S50 Top Speed Cutting Out

[SledgehammerS50]

I have a TT sledgehammer s50. Basically it's running lovely but when ever I almost get near WOT (wide open throttle) it starts to cut out. I can't tell if it's boggy or just not getting fuel, I have tried adjusting the HSN to lean it and richen it but I'm not seeing much difference. I've tried adjusting it up about 1 and a half turns either way but nothing.

I'm absolutely loving it but just haven't been able to give it some real stick yet. Any help would be really appreciated.

[mike1980]

You should only be adjusting the HSN about an 1/8th of a turn at a time, 1 and a half turns is way too much. When you are approaching WOT do the revs go really high or does it sound like it needs to clear its throat?

Edited February 22, 2015 by mike1980

[sean-vrs]

I have a TT sledgehammer s50. Basically it's running lovely but when ever I almost get near WOT (wide open throttle) it starts to cut out. I can't tell if it's boggy or just not getting fuel, I have tried adjusting the HSN to lean it and richen it but I'm not seeing much difference. I've tried adjusting it up about 1 and a half turns either way but nothing.

I'm absolutely loving it but just haven't been able to give it some real stick yet. Any help would be really appreciated.

Fuel starvation, do a 1/4 turn on the LSN,

Will have it singing I'm sure, I run 3 and all have done this.

[SledgehammerS50]

Mike 1980, I only adjust it in increments of 1/8 so no worries there. I said 1 and half as that was how far I managed to get each way before putting it back to normal.

And with regard to the revs going high, it only sounds like the revs increase as they should but then it kinda goes like it wants to clear its throat. I wouldn't say it goes spluttery though, it just looses power and feels like it might stall.

Sean-vrs I will give your theory ago tomorrow. Do think the LSN is literally not letting enough fuel through? Even thought the mid on the truck seems pretty good? She will still pop up given the chance.

Thanks for your help so far guys! Muchly appreciated!

[sean-vrs]

I've had symptoms of a pitta patta throttle when at/near top end speeds then cutting out.

I've richend the LSN and it's cured the symptoms above on different occasions, when adjusting the LSN you need do it with the throttle open else the Middle mixture then goes soar, when it's solid I leave them well alone 3 stage carbs are not a favourite of mine.

let us know how you get on when there at the sweet spot they an awesome truck.

[SledgehammerS50]

Cheers Sean!

I'll give it ago tomorrow. I've just read the first 25 odd pages of the main s50 tread. Some sound advise to be found there. I'm waiting on some red springs for the shocks just to help plant it a bit better but loving every second at the moment. Pukka truck.

[jari]

Back to factory and follow tuning guide instructions stickied in nitro section NOT the truck manual.

A rich LSN can mask a lean HSN. Crankcase loads up with fuel that lasts a little at WOT then lean HSN cuts in. I had that problem tuning a .28.

How does it idle?

The other thing that caught me out... Is the HSN on top speed and sound when AT wot, not when getting there... So you need a big space, and you are looking at how it behaves when you hold wot for a few seconds, not when accelerating.

It is much more obvious what effect HSN changes are having with a big flat space to run it. Start getting it rich and it will sound like horrible throaty cold... But will hold that sound as long as you like... Richer still and it won't even switch into second, but will still hold the speed. Too lean HSN and it will suddenly cut revs.

[SledgehammerS50]

It's been running lovely in every way other than the high speed cut out. I imagine Sean is probably right however it's now looking like I'm not gonna get to use it till Friday as work is busy grrrr.

[SledgehammerS50]

I've tried rich in out the lsn but it's not helped I've also looked at other threads on here which have said to go to hsn 4 turns out and 5.5 turns out on the lsn and work from there. I'm not seeing any difference when I adjust the carb performance wise.

I really need some help with my s50 as at the moment I know I'm not seeing its capabilities.

The main thing I have recognised is the fact it's over heating. I don't have a temp gun but I have been putting a small amount of fluid on the head and it has been boiling instantaneously. Straight away.

Could really do with some decent suggestions to help me sort this out. ( I'm not knocking any of the previous suggestions)!

Help!!!!!

I am getting smoke when pulling off if that helps???

[SledgehammerS50]

I'm actually getting smoke throughout but not too much at WOT...

[jari]

spit on the head is not useful for tuning the S50.

 

if you are measuring temperatures to try and understand what is going on, then you need to measure the temperature. for that you need a digital thermometer.

 

otherwise you need to tune by the sound of the engine.

 

also... these engines are known for running hotter than others when they are tuned.

[jordanp]

if you were in scotland i could tune it for you

[SledgehammerS50]

Jordan, jari and Sean what are your s50 carb settings?

Thanks