Blackie

Saito mounted on a profile (OMP YAK 54) will not stay running to save my life, just don't get it.

Here is the problem and what I have done to try and solve it.

The engine will crank and run but for only a few seconds sometiimes less, then dies. This is with the glow starter connected. Looking at the line there dosen't seem to be any fuel flow, only when I choke before starting.

Using an air compressor I've blow out the entire fuel system and have tried riching up the bottom a full turn, sealed both ends of the carb intake with RTV, tore the fuel tank apart, it checked ok. When chocking before starting that's the only time I notice fuel going to the carb. Took the plug out and checked it to be glowing, and the starter stick has been left on. The high end needle is out 4 turns, none of the above seems to help.

The tank is mounted the same hight just on the other side of the fuse, just a couple three inchs away, (profile).


Is it possible that the low end is to rich? could that cause this?


Thanks
Blackie

William Robison

My Feedback: (3)

Blackie:

I just had a thought. Are you trying to start the engine at idle throttle? I've never had one start well unless the throttle was about 1/4 open, then a sloppy prime, it takes off and runs like a champ.

Give it a try.

Bill.

Cyclic Hardover

My Feedback: (3)

I mounted my 100 on a .40 size P-51[X(] Although I have been flying several years with many different engines to include high performance (Jett) this 100 was my first fourstroke. I went by the book and here is what I experienced. The low end was set at 5 turns open. My high end was several turns.

So I crank it up and it was running roughhhhhhh! Dialing in the high end did not help but leaning out the low end did. Try setting the throttle at idle. Close and re open 5 turns and go from their? After a while in leaning out the low end , it ransmooth down their and then I dialed in the high. The whole process seemed "bass ackwards" from a two stroke.

Build-n-flyer-RCU

My Feedback: (4)

My experience is that Saitos will start and run OK with the bottom sloppy rich, it mostly just makes the idle rough and increases fuel consumption a bunch. But running too lean can cause problems.

I have experienced deadsticks caused by trash in the carb. When this happens I disconnect the fuel line from the carb, remove the high-end needle, attached a fuel filler tube to the needle inlet, and pump fuel through the system backwards. Seems to work.

Have you tried replacing the glow plug? I have seen plugs that would glow but would not run properly for some reason.

Then there are the more obvious checks- no bubbles in the fuel lines, fuel lines connected properly at the tank, clunk is hooked up and not jammed in the tank.

Blackie

All of the above has been tried. The only thing I have not yet tried and that is looking at the valves to see if they were out of adjustment.

Blackie

After reading the Saito FAQ, I'm reading it seems to be pointing at my low end, perhaps I should try hitting in this area some more, richer.

rayb

My Feedback: (13)

Blackie,
I think you're on the right track with the low end thought.
I finally got my Saito 80 running by turning lo speed screw out 2 full turns. Runs rough but at least it'll run while I fine tune it.
Ray

Homebrewer

My Feedback: (8)

Remove fuel line and attach a clean piece of fuel tubing to the carb inlet nipple. Set throttle to start setting that you've been using and then blow into the clean fuel line. If you can't blow into the carb or require a lot of pressure to get air into the carb then you low end needle is too lean and you should richen it a little. Airflow into carb at start setting is a little restrictive but not overly.

Blackie

Everyone, I located the problem after reading back through others troubleshooting steps I did not see mentioned "Bad Fuel" Perhaps I over looked if it was mentioned but bad fuel was the problem. I changed from my 8 month old 20/20 stored in a plastic bottle inside of my trailer to a 15% stored in a metal can also stored in my trailer although the 15% was newer. The engine ran as smooth as a baby's bottom once I found the problem and changed the fuel.

I've also changed fuel storing habits, I no longer keep it in my trailer nor in a plastic jug, everything is now stored in my work shop.

This was my first experience with bad fuel.

Thanks
Blackie

William Robison

My Feedback: (3)

Blackie:

Oops. Sorry, six weeks lost.

I'll out "Fuel" on my "Always mention" list.

Glad you got it working.

Bill.