I am running a new YS170 CDI. Once it starts it runs perfect but problem is starting. Same when it is cold or warm.
When I start the motor will attempt to start for 2 sec and then will die and it will take
30 to 45 sec of spinning the spinner until is will start. After starting this way it takes about 2-3 sec until it stabilized and then it works fine.
From talking to other people I understand that motor should start in less then 1 sec.
All my regular 160/170DZ are starting instantly.
I must say that all tubes and connectors are ok. Fuel pipes are all new as it is a new model.
Fuel is Heli 30% nitro 22 Oil. Valve gaps are tested and ok.
Thanks in advance
Amram Leshed

A litle more:

It sounds like it takes long time for the fuel to reach. I try to push air to the fuel tank to make pressure to drive the fuel forward but this did not help.
could it be malfunction of the ful pump?

Amram

After I get teh first prime of the day into my pump it works flawlessly. Did you buy the engine already assembled as a CDI or did you put the head and backplate on it? You might want tot pull the head and make sure the pump is seated properly in any event, other than that check the tube that goes from the pump to the cam bearing for a pin hole.

Hello and thans for the response.
I purchased the motor as CDI originally.
I am not sure I understand your instruction:

You might want to pull the head and make sure the pump is seated properly in any event,
other than that check the tube that goes from the pump to the cam bearing for a pin hole.

sorry to bother but can you be more specific....

thanks
Amram

Remove the cylinder head form the engine.

Make sure that the pump is seated properly and reassemble.

There is a piece of fuel line that goes from the pump down to the case....check it for a pinhole or replace it with a fresh piece of line.

Also,

If you are running a check valve on the vent line, make sure that it is not sticking. Usually on my first start of the day, I'll turn the ignition off and spin the motor at full throttle for 3-5 seconds to let is get the engine good and wet, and then turn the ignition on and it ill usually fire immediately. After the first start of the day, this is usually never a problem. You might also try richening the pump a little on the bottom. The engine seems to run fine with the bottom a little lean, but it is harder to start.

Arch

OK.
I opened the pump everything is in place. The tube between the pump and cam is fine. The check valve on the vent is ok.
I found something strange:
I disconnect the tube from the black check valve on the top of the head and connect an open tube just for air push pull test.
I try to check if the check valve is leaking. I found out that PULLING air is not possible and that the valve works fine in this direction.

BUT PUSHING air into the cylinder I find air leaking somewhere. I coud hear the air coming out from somewhere but could not find where from.
This was when both intek and outek valves were closed. To the best of my understanding there should be not air leak at this point.

I think removing the cylinder head and reassemble is a good suggestion. It is just pisses me off to do it for completely new motor. :-(
Very disappointing YS!

Amram