Rough starting

[garcol]

I lurk here all the time, and really learn ALOT from you guys.
My question is.....
My little YM155d has a rough time starting. I try to spin it up with the compression release pulled to get some oil flowing. Then when I release it, it seems like 1 cylinder starts to fire right off. But the other seems to take a few. In the meantime it sounds like, and I quote my wife "is there a sledgehammer in the engine somewhere".
I have the throttle all the way open. I have recently put new bearings, sleeves, and pistons in it. Actually about a year ago. But I really dont run it very much.
I realize this is going to have a yammer hammer but geesh. And I also do have to ride the starter for 30 seconds or so to get it running on its own.
It also seems to get worse the colder it gets.
Once both cylinders fire it winds up good and I try to warm it at about 1200 to 1500 rpm's. And it seems to run pretty good.
Any advice would be helpful.
Thanks to all who post.
Garcol.

 

[normde2001]

Do routine maint, air, fuel filter, bleed the fuel lines, adjust valves, test injectors.

 

[mark777]

Sounds like a dirty or bad injector nozzle. Is it the same injector that's slow to catch?
Try this when the tractor is cold but running:
Loosen one line at the injector....one at a time. If it continues to run, it's the bad injector. If it stalls, it's the good injector. They may need to be rebuilt.

Good luck, Mark

 

[garcol]

Thanks guys. Maintenance should be up to date and clean. But I should prob double check the valves are still in proper adjustment. Then go from there.
I kinda thought maybe injector but wasnt sure how to check it, thanks again.