Joystick TX

Bob, looks like you've covered a lot of things that could cause the problem. I would go back to ahicks' suggestion that the problem may be a lean engine. The difference between lean and rich may only be 1/8th of a turn on the carb screw. It took me a long time to get used to setting it and I'm still not good at it.

I don't remember if you checked the carb screen, a partial blockage there can cause a lean run. It is hard to see some of the junk that clogs that screen, I use a squeeze bulb torun cleaner through it.

bob_nj

My Feedback: (62)

I could take the carb apart I guess and check for junk.
Have multiple filters on the supply line and all.

Maybe I just need to live with the sloppy setting this engine needs to stay running and not destroy the plane.

Thanks
Bob

ahicks

My Feedback: (2)

Or let it run "sloppy" long enough to get some time on it? I can assure you that sloppy running is totally out of character for it, but you're not going to get to that point if it keeps quitting on you...

The screen is on the side held in place with a single screw. Anything there is probably going to affect higher throttle settings more than the low speed/idle you're having trouble with.

bob_nj

My Feedback: (62)

Hope you're right about the out of character thing.

The weather is getting better every day here in southern New Jersey, so I'll put more time on it soon.

We didn't really have any Winter this year to speak of.
Highly unusual, but OK with me

Joystick TX

Bob, I agree with ahicks, and this engine is the best running one I have ever had. I fly a lot and do hundreds of touch and goes a month with no problems. At least ones related to the engine.

Will head out to the field in a few minutes and get in a couple of hours flying. The rain and wind have kept me grounded for over a week. Temp in still in the 30's right now, but it will warm up quickly. Got to get in thirty or forty T&G's before the crowd gets there.

bob_nj

My Feedback: (62)

You go Boy!

Good Luck...

pgmeyer

Observation: I have run many gallons of fuel through my Syssa, always started perfectly and always ran strong. One day it did what you are describing here, would not draw prime very well either and did not like to start. I had my fuel system backed by a very fine fuel filter from the tank so I did not think it could be a clogged carb screen. I did everything else possible before taking the carb apart to clean it's input screen. Replumbed tank lines, replaced the input filter to the carb, etc. Finally took apart the carb. Upon examination, there was some kind of extremely fine grayish fuzz in the screen that was almost invisible. I reverse flushed the screen (no other way to clean it, it is too fine) reassembled, and everything ran as brand new -

I am not sure what the stuff was or how it got there. It seemed to "melt" when gripped between finger tips.
Hope you find the culprit without too much more trouble.
Maybe time to rebuild and adjust the carb internals -

bob_nj

My Feedback: (62)

I may do that, but it has about a half gallon of fuel through it...

Slow and Steady

Half gallon doesn't seem like enough fuel to cause the internal filter to clog, But it is easy to check as mentioned, one screw. I found the same fine lint in my filter and gently scraped it out with a tooth pick. I have found that my Syssa got stronger the more time it had running. With only a half gallon through it, it may still be very tight and running hot. If it is stalling on the runway, it may be to rich on low end and loading up. If it idles down slowly, it may be to lean on low end. I agree a loose muffler will play havoc on the idle of a gas engine. Just some thoughts.

Joystick TX

I have seen a lot of junk in the carb filter screen on brand new engines. Mine had some fine particles in it when it was new.

Red Raider

My Feedback: (86)

I own 3 of these engines and have not experienced the dreaded loose muffler issue. Having said that, I agree with Steve about the possibility of the issue being a harmonic vibration. I didn't do too well in trig so take my comments for what you paid for them, but when a sine wave is generated between two machines and the two machines are not in harmonic balance, a vibration will occur that could be the root cause of the problem. The length of the tubes effects the frequency of the sine wave. The solution would be to change the length of the exhaust tunes. As I said, I haven't had this problem, but it could be that I put a 2 1/2 inch extension on each exhaust tube in order to get them out the bottom of the cowl. I use a heat/chemical resistant plastic tube that seems to be vibration resistant as well. Don't remember off the top of my head where I ordered it from, but do remember that it ain't cheap - $17 a foot. Another idea worth experimenting with! I know that I will continue to use this tubing as a standard mounting accessory. It keeps exhaust off the bottom of the plane and MAY be keeping me from having this issue. I'll look up my source for the tubing and share it here if anyone wants it.
Steve

hobby_man

My Feedback: (8)

I would like to know where you got it, I need to do the same type of extension.

MTK

I've written about Teflon tubing from Mc Master Carr many times in these pages. You want Teflon PTFE (not FEP or PFA). Except this size used as muffler stinger stock is less than 17$/ft.....maybe half that much, but I haven't checked.

I use Teflon as my coupling material between my tuned pipe and header, in 7/8ths and 1" diameters. Rated for 550F continuous service. Gas exhaust is only that hot for a fraction of a second as it exits the exhaust port.

Except, if I was to use a muffler, I'd cut the aluminum stingers instead and use tubing constructed from 2 oz glass cloth and Ultra copper RTV as I described earlier a page or two ago. It makes a much cheaper, lighter, softer, sound absorbing extension and will definitely change the harmonics of the muffler. FWIW2U

hyflyer9

Just a guestion here what bolts are coming loose on the muffler is the two main bolts or the little bolts on the back plate . And if it is the back plate bolts wouldn't it be better to just take them out and weld the back plate on solid . I don't see any reason why the back plate was bolted on in the first place .
Like i said just a question.

w8ye

My Feedback: (16)

The main bolts are coming loose

hyflyer9

Was just wondering because i have had my engine since October and haven't even started it yet. But as the weather gets warmer and spring gets closer I will be and i guess now i'll know what to expect .

MTK

Here you go, I checked .... McMaster Carr PN 5239K18, $5.95 per foot up to 49 feet.

5/8" ID x 11/16" OD; should fit the Syssa muffler stingers perfectly. Pop a rivet of button head 4-40 screw into the ally, insert the PTFE tube and tie with a tie wrap or wire

MsgtRob

The two main bolts are coming loose, and I've had a few smaller back plate bolts jump ship as well. I replaced the missing ones and added split ring lock washers to all the backplate bolts. Easy enough fix on those.....but the mains??

hobby_man

My Feedback: (8)

Guys, I can not get this carb on the syssa to pump (walbro)

what does the term wetting the carb mean? I put gas in the head via removing the plug and I put gas into a fuel line and held it higher than the
carb and proped this engine over for 10 minutes with the pug installed and I can not get the carb to pump.

Do I take the carb apart and rebuild it or what am I missing?

Joystick TX

Hobby Man,

The most common problem I have seen or heard of is the choke plate is not covering the carb opening well enough to draw fuel into the engine. I changed to a different type of choke on my engine installation.You can see pictures ofthe mod in mygallery.

It is easy to check the choke. If youconnectabout a foot of clear fuel line to the engine, put the other endinto an external tank and choke the engine, you should be able to see the fuel draw about 1" or so with each rock of the prop. You can also check to see if the fuel will draw if you cover the carb opening with your finger to choke it. Make sure your ignition is off. After the fuel gets to the carb, it may take two or three more prop rocks to get the carb "wet" which means the internal chambers will be filled with fuel.

Once the carb has fuel, it should only take one or two flips to start the engine. I have never had another engine start this easy. I joke with people at the field that if it won't start in two or three flips, I send it back to the manufacturer. I don't of course, but it is that reliable. Had four flights this morningin 40 deg weatherand every start was one flip.

If the fuel does not draw when rocking the prop, you may not be rocking it through enough of an arc. Also, it is possible that the small filter screen in the carb is plugged. It is easy to clean, but you do need to be careful with it. Instructions are on line. I would not mess with the float part of the carb unless you really know what you are doing.

hobby_man

My Feedback: (8)

Thanks, I put the electric starter on it and craked it and I saw the fuel pump up the line

went hot on the motor and it started on the first flip

POWER BABY POWER, I can't wait to fly this Nemesis.

Can I asume if I range check it and get no radio hits and range check it while running and still get no hits I will be able to fly it with no interference? (2.4mhz)

Joystick TX

I MAY have a fix for the loose muffler problem. I made the mod to my muffler last month and put it on my engine, but due to some health issues and travel, I didn't get enough hours on the engine to declare it a fix. Also, I only have a sample of one, so more testing is required. It is an easy mod, but I would not do it on an engine that is under warranty.

If anyone is interested, you can PM me with your email and I can send you the details.

MTK

I'll assume you mean 2.4 GHz. If range checking is the same with engine off and then with engine running, you won't have enough RFI from the ignition to make much difference in flight. This higher freq works the best with these CDI equipped engines. And if you also installed the Syssa IBEC you really won't have problems.

I'm with Steve on the SAP 180....it is the easiest hand starting engine I have used yet in this displacement size (26 - 40 cc)

Joystick TX

The range check with the engine running is a good indication that the engine and ignition will not cause problems. Just be sure your check is in the "power down" mode. I see a lot of people that don't know how to get their radio into the low power mode, or it is not still in it when they make their range check.

I wish someone had one of these engines on a light weight 3-D plane at our field. The way it hauls my 13 + pound Giant Super Sportster around is awesome. I would love to see it on a 10 lb plane.

ahicks

My Feedback: (2)

Some fuel shot into the carb will often do the trick. You just need to get it to fire a few times and it'll prime itself. From then, no more issues.