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New engine pinch... even OFNA truggy box is smoking

New engine pinch... even OFNA truggy box is smoking

Old 02-13-2009, 02:16 PM
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Default New engine pinch... even OFNA truggy box is smoking

Before you say, onoes another break-in thread, please read me out. I'll be able to break in my engine just fine once I get it to turn.

I have a Go 7-port .21. I read somewhere that the pinch was excessively tight, but I wasn't expecting it to this degree. My new OFNA Truggy box, said to be one of the strongest around, won't turn it past the pinch. It does smoke a little, though. lol.

1) I have the plug loosened, but compression isn't really the problem.

2) I sprayed some WD40 down in the plug hole and I've repeated that a couple of times.

3) I heated the head up with my lady's hair dryer.... shhh! I don't know how hot or how long to heat it, though.

4) I've been using a screwdriver and lightly tapping with a hammer to get it past the pinch a few times and hopefully get the pinch worked loose a little.

Nothing seems to work. I'm worn out just getting it past the pinch a few times.

My 8ight RTR was nowhere near this hard to turn.

Thanks in advance.
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Old 02-13-2009, 02:25 PM
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I'm kind of new to the hobby but the only thing I can think of is your locked somewhere. Maybe there is something that is holding your rod from turning or stuck in bearings, but idk
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Old 02-13-2009, 02:26 PM
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Put some after-run oil and run the motor heated up without the glow plug in it. Just let it turn for a bit. Then try it with a loosed glow plug and fuel. A hair dryer won't get it that hot, pick up a heat gun, they're $10 at Harbor Freight and will heat the engine up to 200 degrees rather quickly.
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Old 02-13-2009, 02:27 PM
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It turns freely around the bottom dead center and I can turn it to the compression point, too. I can turn it in those areas with my starter box and my finger. It's only in the pinch area of the piston travel that is so hard to turn.
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Old 02-13-2009, 02:28 PM
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your probably gonna need a heatgun instead of a hair dryer. The hair dryer won't heat it up enough. Go engines are known for being tight at the beginning. Once its going though its a beast.
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Old 02-13-2009, 02:30 PM
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hair dryer does not equal heat gun. you need to get the core temperature up where as a hair dryer will only heat the outside
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Old 02-13-2009, 02:32 PM
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He he - yep those GO 7 and 5 Ports are super tight when new.
I see you have loosened the glow plug off a half turn (just be careful not to go too far with the tapered turbo plug, or you could blow it out and strip the button)
You will need to heat the motor up to operating temps or pretty close. I am guessing your ladies hair dryer isn't quite cutting it. I normally use a hot air paint stripping gun on my new GO motors. Works well.
You need to keep the body warm. If you don't get it started after a minute, then re-heat it and try again.

I don't like the sound of tapping with a hammer and screwdriver to get past the pinch. Just wedge a screwdriver between the flywheel and the chassis and pry it past the pinch.
These motors are exceptionally TIGHT. But when you have it run in you will be more than pleased with the performance and reliability.
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Old 02-13-2009, 02:33 PM
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I use a little fuel in the plug hole to wet the liner. Then turn it over gently by hand to let the fuel out. Some use after run or marvel mystery oil. I have had a hard time starting engines with oil in them. Wets the plug or something I don't know. Thats why I just use fuel.

Make sure that the engine is at bottom dead center. That way the starter gets to spin the motor more before it hits the pinch zone. I turn the engine around backwards 'til I feel it getting into the pinch. That way the starter hits the engine at the top of its down stroke. Gives the engine 300 degrees or so of rotation before it gets to the pinch zone. More momentum this way.

Make sure the box is good and charged.

Heat the engine up more. don't melt your car. As hot as you can get it. Should be unconforable to the touch. Heat the case not the head. The head will heat up with the case.

Everytime the box sticks you have to move the engine past its pinch zone by hand.


OS's are real hard to turn over new. Might be why they go through conrods early in there life. Just something to watch for with your Go if its as hard to turn over as that.
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Old 02-13-2009, 02:33 PM
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Thanks, my brethren.

I'll get a proper heat gun.
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Old 02-13-2009, 02:37 PM
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hairdryer works ok but u need to heat up the crankcase not just the head

put lipos in the starter box or at least put in better connectors if you havent done already
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Old 02-13-2009, 02:43 PM
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Originally Posted by markr04
Thanks, my brethren.

I'll get a proper heat gun.
Good point by Zerodefect, I forgot to mention about the rod.
Rule of thumb with the new GO motors is to pop a new rod in at the 2 gal mark, just as a precaution. Because they are so tight during the break in (and stay tight for up to 1.5 gal) changing the rod just gives peace of mind when you are wringing itīs neck down the straight later on . With the GO parts being very reasonably priced itīs not a hardship.
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Old 02-13-2009, 02:54 PM
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I jsut finished breaking in a 3 Port Go-Tech, and it was hard. Always got stuck at the top. I used a pair of needle nose pliers on the flywheel to break it loose. I dont have a heat gun either and was able to get it to start. I could get it upto about 150 and that was about it. But even that made a big differance in trying to start it.
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Old 02-13-2009, 03:14 PM
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Originally Posted by Madbrad
I jsut finished breaking in a 3 Port Go-Tech, and it was hard. Always got stuck at the top. I used a pair of needle nose pliers on the flywheel to break it loose. I dont have a heat gun either and was able to get it to start. I could get it upto about 150 and that was about it. But even that made a big differance in trying to start it.
From what I have heard, the 3 Ports are not quite as tight as the 5 and 7 Ports (not far off though). Good to see you got it sorted
Getting the casing nice and warm seems to be the trick. Itīs a good habit to get into even when the motor is run in. If you have a heat source available when starting your motor use it. Saves strain on the rod and wear and tear on the piston/sleeve for sure.
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Old 02-13-2009, 03:17 PM
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If your planning on going through alot of engines (looks like you have 4 cars)....Try to get a Hudy engine stand and a onroad header to run in your motors.

I removed the finger gard so I could start motors by hand. Real easy on the conrod.
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Old 02-13-2009, 04:29 PM
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also make sure te starter wheel isnt hitting the chassis and scrubing speed... 1 more thing, let the starter box "spin" up before you push it the rest of the way down to make contact with the flywheel.

Other than that, use a heat gun like these guys are saying, and make sure your glow igniter is strong..... so when it does get spinning it'll start. bump the idle screw up about a turn, the first tank is always the hardest

My GO EB Mod 5 port has about gallon on it and I still cant turn it by hand when cold..... these things have pinch forever it seems like.
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