Brand new 30.5 wont start

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chucked

Well-Known Member
Messages
88
I work at a hobby shop. Customer brought in a rampage mt in a brand new 30.5 that wont start. Getting fire, getting fuel. Seems strange but compression feels low, might just be me, used to being able to carry my tt by the compression in the pullstart on my 26.9 top end. Customer said hes running regular 87 octane fuel. Could this be too low octane? The engine has never started.
 
What you got for a carb?wt813? or wt668?...
for that 30.5cc you should use 91 octane fuel....25:1 mix
If 813 carb..set H 1 3/8 L 1 1/4 for the base setting...And run trim up to open throttle
more...turn on tx..turn on rec...pull trigger about 4 times to squirt fuel in engine...
It will take 6 or 7 pulls to get it stated...cuz there is not choke....
even tho never started ..check the intake pulse hole...for being plugged or gasket installed wrong...It happens.....is the exhaust plugged?
If 668 carb..set H 1 3/4 L 1 1/2 + or - 1/4 turn......set choke......
For the heck of it use new spark plug....I have seen new spark plug bad right from the box......Check the kill button not stuck in.....seen that happen as well...
Hope all this helps...813 carbs are a pita to get started....Slawhammer
 
Its got the 668, carb at stock settings. Tried a new plug for the hell of it, and she is sparking. I'm betting on something happening with the woodruff key on the flywheel. out of time...
 
Are you getting fuel ? I.mean into the cylinder?You get fuel when you prime the bulb?
What about the in tank filter?clogged?Did you blow back thru the lines into the tank?
Too see if your getting bubbles?...If you got spark then the key in the fly wheel should be ok....what does it do when you try to start it?Did you check the new plug ?to see if it see wet.....take the air filter off..see if it will start....Maybe bad foram.......
What have you tried?.......intake bolts tight?.......Slawhammer
 
getting fuel, it had so much in it when it came in I had to dump it out, had a good puddle on the counter. If the woodruff key sheared the flywheel would still be on ok, but it could be spun and sparking at the wrong time. All bolts tight, all gaskets look ok visually. Fuel is not a problem. Ill put $50 on the woodruff key, manufacturing problem.
 
getting fuel, it had so much in it when it came in I had to dump it out, had a good puddle on the counter. If the woodruff key sheared the flywheel would still be on ok, but it could be spun and sparking at the wrong time. All bolts tight, all gaskets look ok visually. Fuel is not a problem. Ill put $50 on the woodruff key, manufacturing problem.

I'm in for $50 that its not the woodruff key....♥
 
Well I was a mechanic for 43 years engine build and you name it...
I don't know what you know as far a engines...some guys in a hobby shop only know nitro
and electric......Yes I see what your getting at with the key on the crank....
Then if you have done all the rest then get a new woodruff key............
But when a person say engine won't start..ya have to began at the basic's....
I have been in the Rc Hobby for over 50 years..mostly nitro....Gas the last couple...
Sounds like you got it covered then.....Slawhammer
PS..Did ya try to add a 1/2 teaspoon of 2 stroke oil in the spark plug hole just to see the compression rise?
Maybe new ..but could have a claspped piston ring from the build....or the piston could be backwards....the dot to the intake side...
 
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Good call Chucked...That would have been the last thing I would have checked...
Very rare for a woodruff key to brake...Maybe the wrong key was used when put together
or the key was crooked and was forced on by the nut......Only other thought is the c-clip came loose from the wrist pin on the piston and was forced puller by the pull starter
and jambed...But that is only a guess....slawhammer
 
I don't think the flywheel was tight enough. It wasnt loose, but I was able to break it free by holding onto the flywheel with my hand. It was my only option. I had plenty of gas. my 1st thought was he flooded it, so I dumped the gas out, and a WHOLE BUNCH came out. so I thought, bingo, cleaned it up, new plug, still nothing... Compression felt loose to me but I had a few other 5th scale guys pull on it and they said it felt ok to them. Maybe my ddm race port 26.9 just has a buttload of compression. Spark was plentiful, even felt it 1st hand. If it wasn't this I was going to think of a port timing issue or something??? but this would require taking the top end off and I wanted to try all my options before taking apart the engine.
 
I just remembered I got a brand new 23cy at my work taken apart. I bet the key ways are the same. This will get him goin....
 
CY or Zenoah call the fly wheel a rotor...the torque for that nut is 1121 inch pounds..
You will have to look up a manual...there all pretty much the same.far as engine model's
go for fly wheels......Slawhammer
PS: Double check the torque value on that nut
 
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Ok I just checked my book for engine specs....The fly wheel nut is torqued to
1121 inch pounds....every thing has a torque value.....Slawhammer
 
Ok..then The fly wheel is called a Rotor..check out the specks..there it is in
130 KGCM..convert that to inch pounds...is 1121 in.pd. It is to my under standing
all bolts and fastners are torqued.....,,Oh I know a quick way for you to find the torque value....Go to DDM web site....click on tech questions....then the next page click
on RC questions....now scroll down find a manual ...Don't matter on engine model..Use G230 ...Click on that and look up torque specks..
All these small engines the fly wheel is called a rotor......
Dose not matter CY or Zenoah engine....,,,,,Slawhammer
 
hey guys. i thought the motor wouldnt start? does it run yet? worry about the torque specs later, for now lets get him going
you said it felt low on compression? put a small amount(teaspoon) 2 stroke down the spark plug port. roll it around. that will create a temporary seal to give it enough compression to start. very common issue.
 
Krypt, i will try and get back on it tonight. Things arent lookin to good at my work, were supposed to have a meeting this afternoon. Im guessing paycuts or even more hour cut backs. If im lookin for a job tonight i wont be able to fool with it for a few days
 
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