JohnF

Don't know if you want to spend the money for a custom header but here's a picture of mine you may have seen before. It's made by K.M. Model Aircraft Components, Canada. If you are interested I'll give you his e-mail address. He will make headers for anything and is reasonable.

airbornrc

My Feedback: (9)

The explanation above is a good one for throttle curve. I fly an Airtronics Stylus.

For exhuast I just used some 5/8 copper tube about 5 inches long and an elbo. I cut a flange out of mild steel and silver brazed it all together

jtisch

My heli radio is a Stylus as well.
I checked my EI unit and am getting a nice spark.I just have to wait for the glue for the PU magnet and loctite on the nuts and bolts to dry overnight and then I should be ready to go.

Mark, any thoughts of going to Dawn Patrol or Cub-nuts down in Mollalla,OR? I'd love to see what you have done!

J

airbornrc

My Feedback: (9)

No, won't be traveling that far. I am pretty busy the rest of the summer. Where do you fly?

jtisch

Fly? I do not fly as much as I should.Seems like I mostly build. I fly my helis and park-fliers in my neighborhood area but occasionally go to Flaming Geyser,RAMS,and Mt.Rainier.

captinjohn

I would like to fly with you guys...but it a bit to far from West Michigan! Capt,n

Ralphbf

My Feedback: (27)

We may have been talking apples and oranges here.
I thought I purchased a 65cc Stihl, ... but it doesn't look like the one in the picture.

JohnF

Ralph, The picture I posted is of my 40cc, B&S, 4-stroke. Sorry if I confused you. I just wanted to show the header pipe.

Ralphbf

My Feedback: (27)

I feel much better now

jtisch

Stihl not running yet (pun intended). Two problems,one of which I fixed.First was the valve timing was off,fixed that.Second,I am not getting fuel through the carb.It will pop and turn over with prime but won't run.I gotta work on that.

J

jtisch

Airbornrc,
Are you using the pulse line from the crankcase area or did you set it up through the manifold?Did you have to do any modifications to the WT-201? Thanks for any help!!

J

jtisch

Well,I got it running continuously with a quite smaller (9mm)WYL carb from my Briggs,if only at idle.I then put on a somewhat smaller(10.5mm) WYK and got pretty much the same, but tomorrow I will play with it some more.I have a feeling this big boy needs lots of fuel as I was running choke just at idle and couldn't get it to transition up without cutting out.Glad the valve and ignition timing seem to be OK.This was an engine rebuilt from parts so I think it is getting easier to start as things (rings)settle in.I am happy to have it running but it sure is louder than the Briggs,though still quieter than any (un-muffled) 2-stroke.

J

JohnF

J, glad you got her running. I think the WT (butterfly) carbs pump more fuel than the WYK. My thinking is that a chain saw would need more fuel than a weed wacker (but I can't prove it) and it seems all the chain saws use a WT. The B&S needs more fuel than air also. I wanted to make sure I could run pretty rich because you know it's probably going to get lean in the air. Just my 2 cents worth.

Ralphbf

My Feedback: (27)

Here is what Ralph at rcignitions.com had to say when I asked.

"I converted 4,2 with the stock mag and CW rotation and 2 with EI and CCW rotation....Making a mount plate for the CCW rotation takes a little bit of figuring and tapping some larger holes in the casting...
I tried a few different carbs, but didn't have a 4 stroke carb with the extra diaphragm spring...They ran about like a G62 with the same size prop...
They run pretty hot, the sensor on the EI engines had to be mounted in a G10 ring instead of the usual aluminum...
Never found a good solution to the carb, but was told a WYK 33 rotary barrel carb has adjustable needles and should work...I made a gasket with a small hole in the center to restrict the intake..That seemed to work the best...
The only advantage to the Stihl over the G62 was the sound and fuel consumption, a larger prop didn't work any better on the Stihl than on a G62....The theoratical torque advantage of a four stroke would take an engine designed with a different cam profile and larger valves..
Might be a thread on RCU, try a search...."

And that is when I did a search and landed here.

I'm waiting for a definitive answer before I move ahead.

JohnF

Wonder how the Stihl would respond to a gas/glow conversion? The B&S really woke up.

jtisch

Ralph,I talked to Ralph as well and that's what pretty much what he said.Here it is as it is set up now.

airbornrc

My Feedback: (9)

I used the pulse port off the crankcase with a hose running to the carb. No mods to the carb. I do have the carb on a 90 degree intake manifold so it would be inside the cowl.

hywong

My Feedback: (2)

"I used the pulse port off the crankcase with a hose running to the carb. No mods to the carb. I do have the carb on a 90 degree intake manifold so it would be inside the cowl."

I had hard time to fit the carb in the cowl. I find the length of the hose would give different response too. Then I try a few velocity stacks.
Still not happy with it.
Mark, can you let us see how you did it with a picture?
ken

jtisch

Never mind,sometimes I miss the obvious.

jtisch

OK!,
I got my Stihl running thanks to a new spark plug cap.It idles and runs up OK. I want to break it in some and I will have to play with the mixture needles a bit perhaps but all in all its not too bad.My tachs don't work well in the shade so I can't post any RPM numbers for now.

J

Prop Nut

My Feedback: (3)

John, does it flip start pretty easy?

jtisch

I don't know about "easy",but I did flip start it .I think once I get the mixtures set,the engine breaks in some, and I get a better "feel" for the engine it should flip start well. I now have a 10.5mm WYK carb on it which is quite smaller than the stock carb but for this particular engine I am not too concerned about getting max HP.At least for now .

Ralphbf

My Feedback: (27)

Where did you get your Carb?

I'm starting to believe a smaller Carb. is the answer.

JohnF

More fuel less air guy's. it's the same with my B&S, 40cc, 4-stroke. Had to go smaller with the venturi. Also, thinking about it the Honda's are the same too. You have to drill out the jet to get it to rich'n up.

jtisch

John F,Where did I get that carb? I've got a bunch of carbs now and I can't remember where I got each one.I think the one I have on now is a WYK 167-1.A WYK 38 is almost the same.

Some preliminary tach #s.With a 22x10 prop top end of 6200 rpm and an idle of @2000 rpm.The top end is really rich for now as I break it in so I expect those numbers to increase,what concerns me is that I can't get a lower idle speed.Hopefully it is just a break-in issue but I have a feeling I may have an air leak somewhere.