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-   -   what to do with a very tight brand new engine? (https://www.rctech.net/forum/nitro-off-road/374554-what-do-very-tight-brand-new-engine.html)

luckyguy2087 02-26-2010 02:07 AM

what to do with a very tight brand new engine?
 
i bought a brand new sirio cl7b. i tried it out but i am having difficulties starting it. the engine is so tight that the bump start is not capable of even turning it. im getting desperate of what to do

neobart 02-26-2010 02:10 AM

Get a heatgun and heat it it up before trying to start it, also loosen the plug about 1/4 turn. That way you won't bust up the rod right away.

luckyguy2087 02-26-2010 02:14 AM


Originally Posted by neobart (Post 7059341)
Get a heatgun and heat it it up before trying to start it, also loosen the plug about 1/4 turn. That way you won't bust up the rod right away.

i tried it already but still wont turn, i tried to turn the flywheel to loosen it a bit but then when i put it on the starter box it turns for a bit but when it reaches the point where the piston meets the piston liner it gets stuck and the starter box wont turn

Roelof 02-26-2010 02:26 AM

Loosen the glowplug with 1 turn.

luckyguy2087 02-26-2010 02:27 AM


Originally Posted by Roelof (Post 7059360)
Loosen the glowplug with 1 turn.

i tried everything already but nothing seems to work.. is it just my starter box? i dont want to buy a new one as it cost over 50£ just for the starter box..

The Working Man 02-26-2010 02:28 AM

Put a little after run oil in it and turn it over by hand a few times. Then put the heat to it. Is the start box up to snuff? It might have been ok but new motors can kill a tired one.

shanty140 02-26-2010 04:15 AM

What are you heating the motor up to? Try and get it to as close to 200*F-210*F. If you are using just a hair dryer, for new motors it sometimes won't be enough and need an actual heat gun. You can find heat guns for $10-$15. Loosen the glow plug a crack.

When I used my Losi Starter Box it was hard trying to get a new motor to turn over and does exactly what you describe. What I did when I went to start it was turn the flywheel as far as it will go in the opposite direction the starter box goes, then went to start it. If it doesn't get past TDC don't keep trying to start it up without putting it back to the bottom, you will just toast your starter wheel. Now that I have my OFNA Blue Top Starter Box it isn't a problem though.

Chris-s 02-26-2010 04:27 AM

-Make sure your starter box and glow starter are fully charged.
-De-grease the flywheel and starter wheel, stops them slipping against eash other.
-Cover any electrics and plastic with tin foil, also the carb as well. Cover the head in tin foil as well to keep the heat in
-Heat the motor up with a heat gun to 200-240.
-Prime the motor with fuel and make sure the starter box is up to speed before starting the engine.

If after a few tries it doesn't start, make sure the motor is still hot.

ABURTON 02-26-2010 06:30 AM

If your un certain about doing it check out the Speed Shop thread on this forum. I own it and we do engine break ins and all kinds of other work. We have great refrences and can get your engine done for you no problem.

my email is [email protected]
AB

geejay 02-26-2010 07:06 AM

Heat Gun and Lipo in Starter Box.

You have to heat it up and take your time......

DarthRacer 02-26-2010 08:01 AM

I had an engine like that once and thought I had a bad one so I took it back to the LHS where I bought it.
What they did is take the glow plug out, put some after run oil in, then put a flywheel wrench on the flywheel and turned it over by hand. It took them about 10min of doing that before we could start it normally.

Sholler 02-26-2010 08:15 AM

All that did was take life out of the motor. You MUST heat them up before attempting to force the piston past TDC. By doing that, all they did was take the metal on metal pinch away prematurely. Always heat a new engine up for atleast the first gallon before starting. It is many times worse to run a engine too cold as opposed to running it too hot.

Sounds like his box just don`t have the balls to turn it over....

Just my .02

geejay 02-26-2010 08:31 AM

I dont see how turning the engine by hand is going to do much


YOU NEED HEAT TO LOOSEN UP THE ENGINE.

Flipfly 02-26-2010 08:34 AM

My Alpha S852 still locks up on my starter box after 1 gallon. It is not unusual.

Heating it up to 200F minimum is a must with a motor like this.

Another tip is to make sure that when you try to crank it on the box, the flywheel must be turned to it's furthest point away from where the pinch starts. If you don't, the starter box will not gain enough momentum before the pinch point.

After run oil is a winner with a new motor, as is adding an extra shim under the button and loosening the glow plug.

If it is so hard to start, I would suggest running a few tanks at a time during heat cycling.

Your Starter box may be no good though, you need a twin motor box for some motors in their early life. i would highly recommend an SMD/fastrax Twin 775 starter box (Ofna in the US).

NitroFreakManHo 02-26-2010 08:35 AM


Originally Posted by Sholler (Post 7060209)
All that did was take life out of the motor. You MUST heat them up before attempting to force the piston past TDC. By doing that, all they did was take the metal on metal pinch away prematurely. Always heat a new engine up for atleast the first gallon before starting. It is many times worse to run a engine too cold as opposed to running it too hot.

Sounds like his box just don`t have the balls to turn it over....

Just my .02

+1 to that!

ALWAYS heat a new engine with a heat gun before attempting to turn it over, and never turn over a cold new engine...it's a very bad idea, and will decrease the lifespan of your engine drastically!

Is your engine flooded and possibly vapour locked ? It sounds like your started box needs attention, or replacement.


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