maherbeemer

I cant get my Zenoah engine to start, well the starter got loose while I was running the car and the bearing from the pull starter went inside the cooling fan and got stuck and stopped the engine so I open the pull starter and took out the bearing also took out my fg pipe and put some high temp silicone to prevent leaking; I dont think there is anything wrong with the engine as the piston is fine and moves normally when you turn the the cooling fan with the pull starter the piston moves up and down normally, my spark plug is fine and the carb is good, so I dont know whats the problem when I pull I just pull and pull and nothing I am not getting any sign of life. Any help would be appreciated.

tapkoote

Do you have spark? at the right time?
A sudden stop like that may have sheared the key that holds the rotor in time
have you checked the timing?

maherbeemer

Yes I have spark; how can I check if its the right time? I dont know I think I might now have good compression as there is spark and fuel? and the carb seems fine.

tapkoote

Pull the starter off and see if the keyway in the rotor and on the crank shaft
line up. You may have to pull the rotor to check that key.It should be obvious
if the key is sheared, acouple degrees wouldn't keep the motor from starting.
Are you running the plastic insolator block on the intake?
Those can warp and leak air, making it too lean to start.
Try a rich setting on the low needle.

maherbeemer

I dont think they are off I think its pretty good. I dont remember but I think when I opened the enigne the piston ring might not be on the position of the arrow could that not start it? should the opening on the piston ring should be on the arrow or that could not have an effect on starting the engine? As for the starter/cooling fan I think its adjusted pretty well as the piston moves normally as it should. I tihnk compression is the problem.

maherbeemer

Can you just point out to me from the diagram which two parts should line up, thanks.

tapkoote

from your parts diagram
the rotor- part number 7319/8- has the magnet in it's rim, which triggers the
impulse through the coil
the hole in the center has a key way cut in it

the crank- part number 7313/8- has a key way cut in it
the key -part number 7313/9 hold the rotor and crank in the correct time
with a sudden stop this key may have sheared in two and the rotor slipped time
heres a pic of a rotor off an air cooled motor pointing out the key way your looking for

maherbeemer

I see, I understand this might be well the problem. Actually today I tried to take off the rotor 7319/8 I was able to take off the magnet; and when I removed the bolt holding the rotor(cooling fan) it wouldn't come off I dont know why is there anything else holding it in place? if you can give me a tip on that it would be great I need to remove it so I can see if they are matching, so what your saying is that mark which is the key way they have to be both matched is that correct? also when I put back the magnet I figured out that it shouldn't be touching the rotor as its hard for it to turn so I had to tighten it a bit above the rotor and tested it when pulling the pull stater and it was giving spark.

maherbeemer

So let's say this is the problem, than when the spark occurs the piston is not in the correct position when the spark ignites is that correct.

maherbeemer

Here's a pictures of a complete crankshaft, where is the key way? 

tapkoote

in that picture, just behind the threaded portion, is a half round slotcalled a keyway
the rotor is a press taper fit-the rotor should be pulled with a puller, you can make one or here's another way
here's a video- there is alot of information on youtube
http://www.youtube.com/watch?v=cKcDQ8YJ8bE

tapkoote

if the coild pick up is dragging on the rotor it wont startgap it with a credit card

maherbeemer

Okay thanks, I will remove the rotor; so just to confirm the key way on the rotor has to match the key way on the cranshaft right? so the opening that is just right after the threaded part on the crankshaft must be on the same diagonal postion as the keyway on the rotor.

tapkoote

yes once you get apart it will be self explainatory
the key goes into the key way on the shaft and then you place the rotor back on
it's the only way it will fit
good luck let me know what you find out
tap

maherbeemer

I removed the rotor and the crank shaft was a bit different than the one on the picture this one has the key way that will go in the key way on the rotor so I made sure that they are fit right I don't know if it was moved or not in the first place???? so I will try it tomorrow with the fuel lines connected.  So thats lined up and I have spark and there is fuel so I don't know what else would be preventing it from starting.

tapkoote

if the key had sheared and through timing off it would come out in two peices
the crank would be scoured
sounds like you didn't have enough gap at the pick up coil

some times a coil gets weak, it will spark outside the motor
but wont spark under compression, do you have another coil
to try? The spark at the plug should be good and strong
I guess you've tried a new plug?

maherbeemer

No I dont have another coil; as for the spark plug its pretty new as it has been ran just a few times and its giving a strong spark....but I dont know if its giving spark under compression? I will have to try and get back to you.

maherbeemer

Installed the engine today put back the fuel lines and still same problem, no sign whatsoever  I don't know what could be the problem.

tapkoote

pull the filter off the carb
put your finger over the inlet and pull it through till it wets your finger
probably 3-4 times, pull it over slowly like that and it should pop and snort
then it should start next pull
if not your not getting enough fuel
have you checked the diaphrams in the carb?
how about inlet screen?

maherbeemer

Okay are you talking about the air filter? I am sorry but can you show me from a diagram, it could be that its not getting fuel but what I did was I took off the spark plug and put a piece of card board on top of the whole and started pulling and it got stained so I think fuel is coming in but I dont know if its enough like you said. If you can show me on a diagram I want to try it, it could be that.

maherbeemer

Are you refering to the opening I have highlighted with red that I need to cover?

Note: sorry I couldn't upload the image due to an upload error, but what I was referring to was number 7336 on the engine diagram I have uploaded previously.

tapkoote

a closer look at that diagram and I see you have a choke on the carb
close the choke, pull the engine over slowly half dozen times
it should pop, like it wants to start
take the choke off and it should start the next pull, thats if every thing is OK
if it doesn't start the motor should be flooded with fuel
of it isn't then you have an air leak some where
or the pump diaphram is bad if it's wrinkled
it should be replaced
sorry can't upload the pic I took part number 7370
tap

maherbeemer

Well the engine doesn't start as I have tried that many times, I don't know about the airleak because I am pretty sure everything is pretty well sealed and put in place. As for the carberator I cleaned it with a carb cleaner spray I really dont know whats the problem it could be from the diaphram but it didn't seem wrinkled to me I think its still in pretty good shape its probably that the engine is not getting enough fuel; I was thinking of buying a new engine until I figure out this problem.

morespeed

i just had the exact same thing happen to me last week. turned out it was the fuel pump. part # 7363 in your attachment.
i took that carb apart 20 times that day and cleaned it, i changed the prime buttom, i pulled like crazy. and still nothing.
but soon as i replaced that fuel pump diafram it started every time after that.


tapkoote is right, check that carb.

maherbeemer

I never took that out when I cleaned the carb so I dont know if its from that but I will give it a try.