Good day gents, I have a Saito FG14 that has 3 flights plus half hour break-in.
I took off for the fourth flight and the engine started losing power after take off.. so I landed, checked out everything and tried again.. engine losing power during take off.

Since, I have tested onthe ground and can't get the engine to go over half throttle before it bogs down. I checked the high speed needle and the low speed needle.
NO response to the low speed needle, it goes to 1/4 open to 1/2 open before it bogs down. FUel lines are fine, no kinks or any issues.
The only thing I can think off, is that the manual mentions that the vent hole on the side of the carb needs 2mm clearance from the firewall and mine is fairly close.. less than 1 mm.. any advice??

Regards,
Patricio

Have you checked the valve gaps? Usually during break in as the parts get worn in a little the valve gaps close up.

Originally Posted by SwampFlier

Good day gents, I have a Saito FG14 that has 3 flights plus half hour break-in.
I took off for the fourth flight and the engine started losing power after take off.. so I landed, checked out everything and tried again.. engine losing power during take off.

Since, I have tested onthe ground and can't get the engine to go over half throttle before it bogs down. I checked the high speed needle and the low speed needle.
NO response to the low speed needle, it goes to 1/4 open to 1/2 open before it bogs down. FUel lines are fine, no kinks or any issues.
The only thing I can think off, is that the manual mentions that the vent hole on the side of the carb needs 2mm clearance from the firewall and mine is fairly close.. less than 1 mm.. any advice??

Regards,
Patricio

I concur with Earl regarding the valve gap adjustments. I have a Saito FG14 also. I had a little more than 3 flights with it but not much more. I had it in 2 different planes and flew them once in a while over many months. The engine was in my opinion fairly new. Then one day it quit in the air and I had to dead stick. Then it just wouldn't run right. No power at all. I noticed a lot of noise from the engine. The engine was also sputtering a bit and wouldn't reach full power.

Took the plane home and did some maintenance on it. The valve gaps had grown so wide that the rocker arms were clacking. So I took off the engine and put it on the bench. Adjusted the valve gaps and voila, running good again.

I will check the valve gap, and hopefully return the low speed needle valve to the setting it was.. I moved it quite a bit in and out...
It is a strong engine and beautiful to look at, but as anything .. it has its learning curve

Remember, the low speed needle is VERY sensitive. Adjust in small increments (no more than 1/8 turn at a time ) and let the engine settle to the new setting a few seconds before going further.

No luck gentlemen...
Checked the valves.. they'r fine
No luck with the needles, it just bogs down after half throttle.
I did put washers behind the engine to free the breather hole.. no luck
I think the diaphragm in the pump is not working, and hence starves the engine...
Thoughts?

Originally Posted by SwampFlier

No luck gentlemen...
Checked the valves.. they'r fine
No luck with the needles, it just bogs down after half throttle.
I did put washers behind the engine to free the breather hole.. no luck
I think the diaphragm in the pump is not working, and hence starves the engine...
Thoughts?

Time to send the engine back to Horizon for some one to look at it. Have you check the timing one the engine? Have you tried another ignition module?

The original ignition module was bad.. replaced it
Haven't checked the timing..
Horizon is quite a bit away...

Originally Posted by SwampFlier

The original ignition module was bad.. replaced it
Haven't checked the timing..
Horizon is quite a bit away...

If Horizon is too far maybe it is time to do some trouble shooting yourself. Take the engine off the plane and put it on a test stand. Try to isolate the situation one thing at a time.

You need good compression. That's valve gap for a good new engine. Can you feel a good amount of compression when you flip the prop.
Next is timing of the spark. You need to make sure it is firing at 28 degrees before top dead center. The CDI module is suppose to advance and retard the timing via software. When in doubt try a different module.
Then comes fuel. Test stand always helps because you can actually see the fuel line. Make sure diaphram pump is working and you have no leaks. Also no fuel clog anywhere. Check the fuel filter and the tank clunk.

Having the engine out of the plane really helps.

Could be your new ignition module is not working well, or you got dirt in the carb preventing engine going full throttle. Did you change spark plug and checked its gap? your fuel is fresh and clean? Engine is in a cowl? pix?

Well, the culprit was found!
I took the engine to our local engine guru.... after much troubleshooting, he took the carburator apart and found one of the plastic seals, the one that sits against the spring, was broken, apparently the spring pushed through (see pictures).
Now, there's no such seal on the spare parts listed at Horizon...
Can you help?
I called Chief aircraft, where I purchased the engine but was left waiting...
Thanks in advance...

Originally Posted by SwampFlier

Well, the culprit was found!
I took the engine to our local engine guru.... after much troubleshooting, he took the carburator apart and found one of the plastic seals, the one that sits against the spring, was broken, apparently the spring pushed through (see pictures).
Now, there's no such seal on the spare parts listed at Horizon...
Can you help?
I called Chief aircraft, where I purchased the engine but was left waiting...
Thanks in advance...

That's a tough one. How old is the engine? Chief Aircraft and/or Horizon should take care of you if it is a relatively new engine. No good reason for the spring to puncture through the seal.

Barring that I would send Horizon an email to inquire about either the parts or the warranty.

I did some quick browse and only came up with the entire carburetor or the carb body from RC Japan.

https://www.rcjapan.net/index.php?ma...je0gu8fnoc6p64
https://www.rcjapan.net/index.php?ma...je0gu8fnoc6p64

You may want to send RC Japan an email asking if they carry or can get you a set of seals.

I went to this site and I found they do sell a set of carburetor seals. One of the seal looks very much like the one on your picture. However the seals set is for a FG60R3 and I don't know if that carburetor uses the same seal as your FG14.

https://store.flitetest.com/saito-en...60r391/p444428

Then the last resort is if you know the material of the seal you may find some one that can copy it and cut it on a laser cutter.

You can send an email to these guys and talk to them. They cut all kinds of gaskets on their laser cutter. I have given him measurements and/or DXF file and he had cut me custom gaskets. I don't know the limitation of the material he can cut though.

http://icbimproducts.com/gaskets/newcart/index.php

The engine is new.. three flights
The ignition was DOA...

Originally Posted by SwampFlier

The engine is new.. three flights
The ignition was DOA...

I think it is time to get in touch with Horizon.

I don't own a Saito gasser but. I have found quite often the carburettors are not specifically made by the engine manufacturer but uses a generic carb used in other applications and brands of engines. Look carefully if you can see any part numbers/manufacturer logos/name and do a search.

This may not be the case with Saito but it won't hurt to explore.