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lincs-lad

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I'm having major problems with the beast!!

its been back to the model shop loads of times and they dont seem to know much about the savage 21.

It seems to start not too badly but it revs up on its own even with the carb closed and the rc gear switched off,

after about 10 mins running the engine cuts out and is very hot! (i dont have a temp gun) after this it is very difficult to start and I've got to wait till it cools,also after it has shut off sometimes the pull cord can be pulled very easily as if the engine has lost compression even though the glow plug is in tight and there is fuel in the engine.

Also after it has shut off i can continually press the primer and there is still air bubbles in the fuel line,after about 3-4 minutes of pressing,fuel reaches the carb (i have checked the fuel and air lines for holes and there ok and air flow through the system is ok and the exuast is clear.If i pinch the fuel line and press the primer i can feel it pressurising so i know the tank/primer is ok.)

h.s.n -is set to about 3 1/2 - 4, l.s.n- is set to about 3 1/2 turns from closed although i have tried richening and leening both needles and adjusting the idle screw.

i am using 16% model technics duraglow fuel and have tried a few different glow plugs from number 3-8,the temp outside is about 10-13 degrees (c).

i would be very gratefull for any suggestions or help as I'm creeping towards the end of my tether (pissed off) ,thanks guys.......
 
Sounds like youve got a air leak some where check where the carb conects to the engine backplate etc pull fuel tank off putin water pinch off one line blow into other see if it bubbles ... other will post some tips i can't think of right now
 
Originally posted by lincs-lad
the pull cord can be pulled very easily as if the engine has lost compression
Click to expand...

Rob, I have the same situation on my Ofna Hyper 8 port. The pull cord is too easy to pull. I don't feel any resistance. Do you know what this means?

Lincs-lad, you're using 16% fuel? I remember HPI saying not to use any fuel under 18%.
 
Wish i could help ya with that but i dont have any exp with that motor and easy to pull worrys me does it run normal ?
 
It runs normal, about 230-260 degrees after running it hard. The engine starts after 3-4 pulls.
 
might just be normal loosening up after it warms up my os is little tighter cold than when it warms up
 
I also think it sounds like an air leak especially with the bubbles in fuel line. Also I would check the MID needle setting screw it right in counting number of turns. write it down and then see if it matches what the manual says. ( 3turns I think not sure. should be flush with housing.) Get 20% nitro I use blue thunder I'm in UK and found it easy to come by and works great. OS A5 glow plug. you need a medium cool plug. set all needles acording to manual and lean it out 1/4 to half a turn from that for each hsn & lsn.

when i start my savage i pump the primer till i hear the fuel bubbles squirting through the carb then i give it 3-4 more pumps. I turn on the radio and car, turn the throttle trim clock wise all the way. give it glow plug and it starts first pull 90% of the time. I can then plonk it down and drive in circles till its getting warm and then i turn down the throttle trim. and off we go. I do it this way because i know that full throttle trim is 1/4 out on the carb, its the same every time then.

check your air filter. is it clean. pull it off spray some wd40 in the carb too.

i would change the fuel line anyway its a cheap place to start.

hope this helps.
 
Your primer could be spent on your tank too (source of air leak). I've been waiting to hear of one going. Possibility.

Other than that, have you tried setting your needles back to stock and just turning in you HSN about a half a turn from there?

Lastly, make sure your idle set screw is properly seated. I have seen this cause the same issue. Best way to know will be to screw it almost all the way in and then back it out until the opening inside the carb is the same thickness as about 2 credit cards.
 
You might wanna switch to some higher nitro fuel percentages. For a bigblock, 16%might not be too good for it. Try the air pressure trick and if that is fine, its probably something that someone WITH rc nowledge will have to look at personally. Got any pics?
[move]-Kellen[/move]
 
thanks for the help guys i will try your suggestions though i think there may be something wrong with the engine or the setup.

how long do your savages run for? do they run a full tank? cos mine always shuts off before half a tank,i can't remember the last time i shut it off my self.
 
Then more than likely you are running wayy too lean.

Set the needles back to stock, turn the HSN in half way from stock and make sure your idle screw is set. Screw the idle screw in almost all the way (to make sure it is seated right) then unscrew it til the carb is open about 2-3mm. When you get it started you may find the idle too high. If so, just unscrew the needle a little more. Do all this with the air filter off so you can see the opening inside the carb.

Good luck!
 

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