Maxam

My Feedback: (62)

5-100 owners, I have a concern. The Waco has now flown 5 times. A beautiful flier. Being a new plane, I pulled the cowl to inspect mounting bolts, rocker clearances etc. I was oiling the rockers and valve springs. No stuck exhaust valves, very free moving BUT! I found that the valve stems had significant side to side free play in the guides. The intake valves do not!! Would you guys check your engines to see if this is the same in your engines. Normal?? Remove the exhaust pushrod and put your finger on the valve tip and push the valve down a bit and then move your finger side to side to see if you have the same situation. Thanks in advance! -Tom

Robert Dochterman

I tried for ya but kinda of hard to tell by feel. I think maybe i was feeling the valve spring movement. Only way to tell for sure would be with a dial indictor. It would be sometime before i can do that. How many gallons of fuel since new.

Maxam

My Feedback: (62)

Around 2 gallons. The engine uses very little fuel. Thanks for trying. -Tom

Hyjinx

Hey Tom
I checked my 125 and another 125 that flys our field. The stems in these two engines have almost no shake between the stem and guided section when the valves are off the seat. Barely enough to detect.
These are also the two engines that displayed the "sticky" exhaust stems discovered and mentioned here in the thread after break in. Fuel conditioners with upper cylinder lubes seem to have solved that.
Aaron-

sharam

My Feedback: (2)

Hi,

I broke in (2 gallons) my UMS 150 - she is running well. Just had her up in my CY Model FW190 (96" span) on its maiden flight. All worked perfectly. No 1 cylinder max temp was 237 degrees. Still running rich with lots of black gunk coming out. No pump and the engine ran quite smoothly. Love the sound. Plan to lean her out a bit next week.

Amsoil Dominator, 110 Octane Sunoco Racing Fuel

Carlo Vangompel

Hi,

Does it run properly without a fuel pump?
no problems?
I also have a UMS150 and am struggling using it or not

carlo

Hyjinx

No pump no problem. First report of that. Which walbro does it have on it from the factory?

Carlo Vangompel

I will check it and let you know when I am back from holidays,

Carlo

sharam

My Feedback: (2)

Carlo, my one flight went quite well, engine performed predictably, landed, taxied back and killed the engine with throttle cut. I plan to fly her again this week - will report back.

Hyjinx, factory carb. Will look for a number and let you know.

I have a temp sensor on cylinder 1, the highest temp in flight was 237 F.

Has anyone successfully operated these engines with a pump? Still way too early for me to claim victory.

Maxam

My Feedback: (62)

Congrats Sharam! Hyjinx, thank you for checking the valves. My valves are quite loose, but the engine runs well. I would have thanked you earlier but I have not been getting post notices. Get the pump, the pulse tubes will get gunked up and no longer give the carb the pressure waves needed to supply fuel.

Hyjinx

Hey Tom. All good dude. I don't get notifications and rcu's site is crashing Google. Sort of off topic but have you converted either your R325 or your Seidel (German ) to gas? I've put kits from CH on both of mine and am having the same trouble. Won't run reliablely without a pump. Then the pumps at lowest settings are flooding all three idle circuits. Walbro feels the pump pressure is forcing the reaction by overcoming the poppet valve (valve and seat) and flooding the circuits simultaneously. I am wondering if these smaller displacement radials are going to require a different carb design. Problem doesn't seem to be present on the larger displacement engines. Any sage wisdom to share Sir?

Maxam

My Feedback: (62)

Well rats Hyjink.....I do not have either engine presently. When I had my Saito 325, my conversion was changing the carb to the OS Pegasus 240 improving the engine greatly. You can try a stronger spring in the walbro. I had a lawn mower shop that had tons of walbro springs of different tensions but out of business now. Try stretching the spring???????

Hyjinx

Thanks Tom. Yes I have been adjusting the actuator tab on the arm and have manipulated the spring by stretching but can't seem to get it. Working with two walbros and one Chi com carbs. All new. All reacting basically the same on either engine. The Walbro tech mentioned there were different spring sets available, and thought this may be the situation. Adrian felt adjustment on the controlling tab (arm) would help. Multiple different settings go from not much better to worse. I'm wondering if tracking down the available spring variations must be next rabbit trail. Or simply refitting the engines with glo carbs and sparking methanol, and getting back to flying instead of wrenching

Maxam

My Feedback: (62)

For the smaller engines I think glow is best. From the 7-35 to the 9-99 glow runs cooler, is lighter and reliable. Those ignition modules are heavy. No I do not have on-board glow igniters on my glow radials.

Robert Dochterman

Why not regulate the pressure/ volume right before the carb?

Hyjinx

Yes Tom. Both of these engines ran well on glo. And without OB igniters. Converting both of these was a expensive blunder. But there was reason in the intent. WCS they will both get glo carbs and methanol with spark, as you know these boat anchor multi cylinder ignitions are as heavy financially as they are on the plane.
Thanks Aaron.

Hyjinx

Thanks Robert. I have been tinkering with regulation. Fixed reduction should solve the problem on the low speed circuits but may starve the engine during increases throttle. Haven't ruled it out but have been focusing on the carb. These carbs are a miss application according to walbro. So it's really a game to make this work. But I do know it's possible, Ive seen em running well on u tube.

sharam

My Feedback: (2)

Ok, today I had no luck running the engine well. First it fired right up and after warming it up, I throttled up but the engine seemed starved for fuel. Richened a bit at a time but I ended up chasing needles for a couple of hours. Rich, lean factory reset, etc., no avail. Perhaps the pressure feedback lines are all gunked up as Maxam mentioned - thx!. I will buy the pump.

Which pump do you guys recommend?

Maxam

My Feedback: (62)

The APS powerfuel. It has its own regulator.
You can get it from Vogelsang Aeroscale or CH-ignitions

1967brutus

Mind you, that is NOT an optimal fuel, your engine is designed for 95RON or thereabouts, I believe in the US that is comparable to 92MON if I'm not mistaken.
It will run better on what it is designed for. 110 Octane rating will burn noticably slower, reducing performance.

Hyjinx

I bought and received the TCS pump. Shopping went well and was received stateside within two weeks. So far I am very pleased with it. One very nice initial option is running at very low voltage and can deadhead without damage based on its instructions. Hence constant minimal pressure at the carb without a plumbed in return line. I am using it on two smaller radial gas from glo conversions. Bottom line. Happy with the pump. May post more on "everything radial", as it is a bit off topic here. I am chasing trouble with the conversations, some to be learned yet, but progress is happening.
I have multiple APS units on several builds, but this pump is lighter, easier to use and fit, and outperforms the APS by being more regulatable with lower voltage battery technology.
More to come.
Aaron-

sharam

My Feedback: (2)

According the CH-Ignitions, the fuel is fine.