FM-150 experience - question

I was having issues with my IO-375. The engine didn?t run right at high altitude and idle mixture adjustment was almost impossible. In fact I still have the issues although to a lesser degree.

See this thread: http://www.vansairforce.com/community/showthread.php?t=161204&highlight=FM-150+issues

I?m blaming the FM-150 however I?m also aware that other things could cause my issues.
1. I?d like to know how does the FM-150 perform on other engines, especially at high altitude?
2. Where is your mixture lever when leaned out during cruise?
3. Is your mixture lever responsive during the first half of travel?
4. What is your take-off fuel flow?
5. Is it possible to exchange the main jet in the field? Any special tools required?

Anyone ??

Call the man.

I have a FM-200 that has performed flawlessly for 2200+ hours. They are pretty bullet proof. I would suspect an induction leak may be your problem. Call Don Riverra at Airflow Performance. He is very helpful.

SuperCubDriver said:

I was having issues with my IO-375. The engine didn´t run right at high altitude and idle mixture adjustment was almost impossible. In fact I still have the issues although to a lesser degree.

See this thread: http://www.vansairforce.com/community/showthread.php?t=161204&highlight=FM-150+issues

I´m blaming the FM-150 however I´m also aware that other things could cause my issues.
1. I´d like to know how does the FM-150 perform on other engines, especially at high altitude?
2. Where is your mixture lever when leaned out during cruise?
3. Is your mixture lever responsive during the first half of travel?
4. What is your take-off fuel flow?
5. Is it possible to exchange the main jet in the field? Any special tools required?

Click to expand...

Can't answer all your questions but I can offer the following.
AFP makes a great product, FM200 for a >1k hours on last engine with no issues.
New Titan 375 installed recently with the FM150, so far no issues and engine is running great. TO FF is right at 17GPH with about 27PSI FP, idle mix was set a bit rich from the factory. Mixture adj is quite sensitive, I usually turn one flat at a time to tweak
Current nozzles are .028 but switching to .024 soon which will improve hot idle and low power atomization. EGT/CHT's all good.
Yes you can change the main jet, info in the manual.
No high alt work yet, still breaking in the engine.
Mix lever about the same as the old FM200, from memory about an inch or so out for my high power settings down low to bring EGT back up to around 1250 (keeping it rich for break in).

Thanks for sharing.
I?ll go and check again - after many times already -for an induction leak.
It?s a pity that my takeoff fuel flow is still slightly low because the fuel servo just came back from AFP.
Smaller nozzles is next, will see how the engine responds.

Flawless in use, difficult to adjust idle-mixture, great support

Hello

I have a FM-150 in my RV-7A, IO-320. 137 hours, works great.
Idle-Mixture is difficult to adjust, missing here a system like that one from Precision Airmotive, where you can just ad a click and so.
First inch of travel does not much to the fuel mixture.

11.4 USG at 2250 RPM, TO run @ 1300ft field elevation.

Rebuild buddy's RV-4 with the same system, because of this three reasons:
- I know the system
- Never left a beat on my RV
- Direct contact to the designer of the system!

Call Don Rivera, tell him your problem and he will help you!
I made many calls before I bought a system, he took the time to answer all my questions, he knows also all the other systems quite well.

SuperCubDriver said:

It?s a pity that my takeoff fuel flow is still slightly low because the fuel servo just came back from AFP.

Click to expand...

There are way too many variables to judge mixture from fuel flow. Instead, determine degrees EGT in relation to peak.

Start reading at post #35. Study the data.

http://www.vansairforce.com/community/showthread.php?t=86179&highlight=peak&page=4

My datas are not really hard values. During takeoff the engine runs well with good power. The climb rate leaves me only a short time in sea level conditions anyhow so I don?t worry too much. Recently I saw EGTs around 1420 F on takeoff at sea level DA, my max EGT during cruise I ever saw was around 1550F. So when reading the "classic Lycoming document" I should be a good 200F below peak EGT to be on the rich side of best power at an A/F of 11:1 - is that correct?
Most others are reporting takeoff fuel flow around 17 GPH, I know it depends, but just over 15 GPH seems on the low side to me.