Big Bore Kit Installed, Motor Wont Start

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KauseKaos

KauseKaos

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I finally got around to installing this big bore kit I bought from DDM on there Black Friday sale. (Part# ca370). I put it all together on my Zenaoh 23 and was told this would bump me to 28.5 but it won't start. I took it apart and rechecked my installation but it still won't fire.I'm running a 813 carb on it. Any ideas on what the cause could be?
 
make sure fuel is going threw the lines when u prime it, re-set ur tune to factory settings, if u don't know the settings ddm's site has a tech page and u will find the answer there.

did u gap the coil correctly?

are ur kill wires touching anything?

have u checked for spark?

have u tried a shot of carb clean through the carb to give it a direct source of fuel and see if it fires then?

is this a new carb or previously used carb?

does the plug have a gap at all, sometimes in transit they get smashed closed?

since u have an 813 do u have a v-stack with a choke , or are u using ur finger?
on a new engine u may need to choke it with ur finger to get a large dump of fuel in the cylinder for initial start up.
 
I don't know the factory carb settings. But the 813 carb is fairly new. I just installed it on the motor and used it twice before the kit. I have a v-stack but no chock. Been thinking of swapping out for one with the choke. The motor was getting fuel and we used the tool to gap the coil. I'm gonna take it apart again try a thicker gasket maybe. Oh yeah and I tried two different plugs and I was getting spark. I also changed to a MSD plug wire.
 
Dry out the motor by tipping it upside down without the plug and pulling 10-15 times. I bet you just have it flooded. The 813 likes stock settings and not much more. Good luck.
 
is it a new plug? if not put a new one in.

remove the air filter, put your thumb over the v stack and give it a few pulls, this will help to start it.

good luck.
 
KauseKaos said:
I don't know the factory carb settings. But the 813 carb is fairly new. I just installed it on the motor and used it twice before the kit. I have a v-stack but no chock. Been thinking of swapping out for one with the choke. The motor was getting fuel and we used the tool to gap the coil. I'm gonna take it apart again try a thicker gasket maybe. Oh yeah and I tried two different plugs and I was getting spark. I also changed to a MSD plug wire.
Click to expand...

changing the gasket wont do a thing, ur prob is somewhere else.

on ddm's website u can go to the tech section and get the stock settings for the carb
 
stock carb settings are 1 1/4 on L and 1 1/2 out on H. same as the other walbro carbs for these motors.

is the plug Wet looking? if the plug is looking very Damp or wet, its flooded.

813 has an accelorator pump in it. so everytime you give the trigger a squeeze you get a shot of gas, where the other non pumped carbs have to depend on the air flowing over the needle ports to draw (siphon) the fuel from the carb. so its very easy to flood a motor with the 813 by simply squeezing the trigger 4 or more times.

deflood the motor as BTB suggested, drop in a new plug no squeeze of the trigger, and give it some pulls.

are you sure any remote kill switch is activated and allowing the coil to spark?

do you have spark?
you can gap the flywheel with any standard business card. same with the plug. any motor with no issues should run fine with these gaps. if not, there is another issue that the coil/plug gaps.


is this a 36mm GP290 topend?
a yr ago. seemed there were a series of the 36mm piston rings that wernt quite true. but it was only a few.

if all seems fine, but it wont fire,im going to say it may be a funky ring. to check this, pour a table spoon full of straight 2 strok oil thru the plug hole. roll the rc around so the oil coats the piston top and ring. its important for you to bring the piston to near TDC of the stroke to close off all the ports from the ring, this way the oil doesn't just run into the bottom of the case.

once you have the piston/ring coated, put the plug in and try to start as normal. if it fires up, then the ring may be a problem, but running it may help seat the ring and get it to seat to the cylinder walls all the way around.

typical starting sequence for 813s

1 turn on tx then rx
2 prime bulb till firm and give 2 more pushes
3 squeeze trigger 3 times, let set to idle
4. pull it over wihtout touching the throatle.

if all is good, it should fire up in 1 or 2 pulls. if it doesn't give it one squeeze of the trigger, reset to idle, and pull a couple times. try once more if it doesn't fire. if it still doesn't fire up, or sound like it wants too, you have something going on.

i have the 813 on my ESP 27.2 which has been rebuilt after 12 to 15 gallons.

3 to 4 squeezes of the trigger, and 2 pulls and its typically idleing.

hth and let us know how your making out.
Tim
 
Still won't start. It kinda feels like I have no compression. What do I do now. The motor worked great before I installed it. Yeah I know if it aint broke don't fix it but I wanted more power. I don't know what to do. I was thinkin about pulling the whole motor apart and adding the 2mm stuffed crank and that copper gasket and changing the rest of the gaskets.
 
I had a headkit had no compression and sent it back. I wrote ddm and asked if they could check it over as I got it locally new but in a trade. they just replaced it...
 
Dribble some petrol straight into the carb....open the throttle to let it in the case....then pull pull pull......should fire after 3-4 pulls......if not..it will be ignition related.

If it does start this way but doesn't continue running.....it is carb related.

This is the test I perform whenever someone brings dead 2 strokes to me to fix......which is quite frequently.

Most of the time it is spark related......it may have spark....but not sufficient enough to fire.
 
If you ever in doubt on the way your piston is to go back look in the exhaust port and you should see the tear drop that will keep the ring ends from being free from contact with the cylinder. If there was no tear drop the ring ends could snag the cylinder and tear it up.
Not all but most pistons will have a mark that will also help you keep the piston pointing the right way.;)

Some motors are a real pain until they finally pop and get going. Not sure the reasoning but it must have to do with the seating of the ring.

You can also drip a bit of two stroke oil in the cylinder. This will allow the ring to seal and more pressure to build in the cylinder.

Keep us informed on what you find.:huh:
 
What bearings should I put in the crack case and do you know what's the part # for the seals for bearings?

I'd figure ill just tear down and start again cause I wanted to add a 2mm stuffef crank anyway.
 
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