Wufnu

My Feedback: (2)

Got the Kioritz running on gas/glow (23.6cc), man is it fun to let it go full throttle for an entire tank. Doesn't require constant glow power, either. Dad went wayyy back from it (20-30') and watched as the wind blew his unbuttoned shirt back some.

Anywho, I was wondering just how you know when the carb is too small? I got it to run but it wouldn't prime itself, even when I would block the carb venturi intake (may be a leak, previous owner put some sort of 1-2" tube from the venturi, I'm assuming to get it to stick out of a cowl or something). If I put some straight glow into the cylinder (requiring removal of the glow adapter) and started it it would run for a bit and either 1: get fuel from the tank and keep running or, 2: slowly die and require more priming.

After I got it running, and to my ears it sounds like it's running very well, I noticed that I had to have the high mixture almost fully leaned (as much as I could turn the screw tight with my fingers). Does this mean I need a larger carb? Also, the high mixture screw is the one closest to the cylinder, correct? Would a larger carb fix the problem it has priming itself? I'm not running exhaust pressure so I'm not sure how I can prime it like I'm used to (blocking muffler, turn over a few times).

For fuel I have Tower 15% nitro 18% oil that I'm mixing with HEET (stuff to remove water from fuel lines) at a 1:1.8 ratio, then I mix that in a 1:2 ratio with straight gasoline.

I'll get a tach reading tomorrow.

emtpmike

I am fairly new to gas engines myself, so one of the more experienced guys can back me up if I'm mis-speak myself. The needle closest to the cylinder is the low speed needle, I believe. Both the low and high speed needles will affect the top end, but only the low speed needle has effect on the bottom end.

Most people I've seen use a carb with an 11.11mm Venturi on motors in the 25cc range. Walbro stamps a number on the inlet of theirs in 64ths of an inch. Your looking for a carb with a 28 stamped in the inlet. (28/64ths of an inch = 11.11mm) I'm not sure if its on the intake side or the engine side.

I have a 25cc Poulan that came out of a Weedeater trimmer that I'm running gas/glow in. Like you, I mix 1 part 15% Cool Power with 1 part HEET. I take that mixture and mix it with twice the amount of gas. i.e. 2 oz. Cool Power, 2 oz. HEET, 8 oz. Gasoline. I don't have any info on priming issues because I use a starter to turn it over. I get around 7500-7600 rpms with an APC 16 X 8.

I tried to find the carb adjusting tutorial I used to adjust mine by, but I can't seem to find it now and it's getting late. Hope this helped somewhat. I'm sure someone with more experience than me can answer you better. Good luck!

Mike D.

Wufnu

My Feedback: (2)

That actually helps alot, now I know which screw is the idle. What's odd is that I got it to get to a decent rpm by leaning out the idle all the way, but that would explain how come if I went lower than half throttle it would die. Guess I need to richen up the idle and lean out the high some more. I believe the correct proceedure is to set the high mixture first then adjust the low, then readjust the high, readjust the low, until they both kinda fit. Did I get this backwards? I'll try to find that thread you mentioned.

I looked up the carb this one has, it's an 8mm for sure. Like I said, it ran pretty darn good, suppose the numbers will tell the truth as I doubt I can accurately guage performance on an unfamiliar engine by ear. Can't wait till tomorrow, I want to see what kinds of numbers I get. I'm running a 16x8 right now but will likely switch to a 16x6. I seriously need to balance the prop, the vibrations were horrible and the whole time I was watching the fuel splash around the tank. Like I said, bad, no way I'd put it in a plane like that.

What kind of starter are you using? My standard 12v wasn't up to the task at all. I don't much like the idea of buying a high torque starter when I'm already on a slim budget but I guess thems the breaks. I've heard of people using drills with an oversized starter cone chucked in, might try that option.

Thanks again!

coralcape

My Feedback: (4)

Your procedure for adjusting the carb is correct, and the hi spd needle is farthest from the cyl. I have found that I can use a standard 12v starter, if I use 24volts. Good luck, red

emtpmike

I use my standard Hobbico Torqmaster 90 12v starter, but I have to hook it to my car battery. My starter panel won't pull it. I saw a post either here or on www.spadworld.net where someone had mated an 18v cordless tool battery to their starter to use like one of the purpose built battery packs.

I've read both ways to set the needles. I think the way I did it was tune for the leanest idle I could get, then richen it a bit. Then once the low end was set, I would goose the throttle and if it hesitated any, richen the top end until I could give it full throttle. There was a good article I read describing this procedure and if I can locate it again, I will link it.

av8tor1977

My Feedback: (6)

Check here: http://www.bmeengine.com/html/manual.htm

Start with both needles about two turns out. Then set your high speed needle for max rpms, then richen it about 1/8 turn; no more. Then adjust your low speed needle until it will idle smoothly without loading up. It should idle for at least a minute without slowing down or quitting. Then try "gassing it" to see how the transition is to higher rpms. If it hesitates, richen the low speed needle slightly and try again. Richen the low speed just enough that it doesn't hesitate on the transition. Then check the high speed needle setting again. It will most likely have to be fine tuned again. Check the idle and transition once more, and go fly.

AV8TOR

captinjohn

I like to set the Hi-speed needle for top RPM and then richen it a tad to drop RPM about 100-150 RPM. Then I set low-speed needle for smoothest idle. Sometimes you have to richen the Low-speed needle if transition is not good. Too lean a mixture on idle... it will bog out or quit, on quick acceleration. Too rich on idle the engine will load-up or run rough. This all has to be done with engine warmed up. Well ....thays my way!!! Capt,n[:-]

Wufnu

My Feedback: (2)

I just finished fighting with it, before checking this thread. It would run on pure glow (after I'd pour some into the cylinder) and die, over and over again. I pulled the plug and it had some weird gunk on the coil. I don't even know how to describe it, it looked like a piece of sand or something but wasn't. It was pretty hard. That was my only four stroke plug, too Put a Fox two stroke plug in it, with idle bar, and after priming it with glow about five times (it would run and die) I juiced the control panel to get it in the "red zone" on the glow power meter and it started (also after fiddling with the needles for about 10 minutes). It ran at full throttle and it ran without the glow starter but lowering the throttle = death. It also missed sometimes.

I also fought with my silly tach, man that thing was annoying. Does your engine have to be sitting in bright sunlight? It was partly cloudy but the sun was out, I was in the shade of a tree. Took me FOREVER to get a reading on the tach, looks to be about 6600 rpm with a 1680 Master Airscrew prop. Kinda disappointing, perhaps I'll get better with a hot four stroke plug.

Any ideas of what the stuff on the plug coil was? It wasn't the white buildup most people have, I really don't know how to describe it besides it had the color of sand and was pretty hard. I'm considering taking the engine completely apart and cleaning everything, just in case. Nothing floating in the gas tank, don't think the gas is old. Also, there seems to be black soot on the glow plug idle bar after one tank.

I don't suppose any of you guys live around Knoxville, TN do ya? Nobody around here that I know of even knew of gas/glow.

Wufnu

My Feedback: (2)

Oh, one more thing. I'm having a heck of a time getting it to start without having to prime it with glow fuel. For example, there was fuel in the fuel line at the carb when I first started but couldn't get it to start, so primed it with some glow fuel and it started. I'm starting by hand, think that's it? With glow a sligh push in the opposite direction and it starts right up, don't get it.

Having to remove the glow adapter and pump some glow into the cylinder every time I start it is getting old, fast.

captinjohn

The Nitro in the glow fuel is what is helping it to start. Maybe the oil content is higher too...giving the piston & rings a better seal. How is the compression on the engine now? Capt,n

Wufnu

My Feedback: (2)

Compression is good. Maybe even great. Like I mentioned before, it was hard to get it to go through a forward stroke with glow in it, it would kick back hard. Best way was to flick it backwards. It's much easier to spin it backwards than forwards, which makes sense. I managed to get the starter to spin it, and it spun it plenty fast (I just had to keep super pressure on it or it would go off center and fling itself off). Even with the starter spinning it, glow power applied, and fuel at the carb in the fuel line, it would not start on my gas/glow mixture.

I ran it again, I wanted to get an accurate tach reading. 7300rpm with a 16x80 master airscrew prop, the sun helped and there wasn't much variation at all. I also followed the proceedure in the BME starting instructions and the two turns out (I was at 1 1/2 before) worked well. I had to lean out the high needle some and I need to richen up the idle mixture some. I managed to get it below half throttle, it died shortly thereafter like someone hit an off button somewhere. I'll richen up the idle 1/8th of a turn or so and see what happens.

What's most important to me, right now, is why it will run on gas glow but will not start with gas glow. I just don't understand it. The starter was spinning it very fast, full tank of gas at the appropriate level and fuel is at the carb, strong glow heat, and nothing. I could try adding some more HEET to the mixture, perhaps? But then again, nobody else is running this engine on a different ratio, so I shouldn't have to. I know it has compression, I know it has heat, that just leaves air and fuel. But which? If it will run if I prime it with glow but won't if I don't, what does that mean?

captinjohn

I have seen this happen....guy cranking a glow engine real fast with a electric starter. I told the fellow, let me try to start it. I let it set a few min for the glow plug to burn out excess fuel. Then I back bounced it and it started on first bounce. What is happening...the incoming fuel mix is cooling the glow plug too much. The faster you spin it...the more glow gets snuffed out. Capt,n P.S. 33 years experience with glow engines

buck1856

My Feedback: (49)

In the (gas engine,glow fuel,no ignition thread) its stated the formula is:
a)-car or plane fuel 10% nitro---10% oil--oil is the keyword here.1 gallon
b)-regular gas------------2 gallons.
This is all the ingredients.your running 18% oil as stated in your opening post.dont use heet.Av8tor also stated in the post about opening up the detent lever that controls how much fuel enters the diaphram section to let more fuel past the needles.hope this helps a little.I bought some fuel called white lightning at the LHS that has 8% oil content but has 20% nitro.ran ok in my echo but the rings where not that good.maybe av8tor will step in and see what he thinks about the white lightning blend as hes done more testing.

av8tor1977

My Feedback: (6)

White lightning? Sounds good..... burp. [&:]

AV8TOR

coralcape

My Feedback: (4)

As to engine not starting when you choke it. I have had this happen when I removed the choke assembly. The problem was the shaft holes in the carb allowed air to enter, even though I had my thumb over the intake. Solution, plug up the shaft holes. If this is not the case and you still have the choke assembly, there may be a hole in the choke butterfly that needs to be soldered closed. Good luck, red

Wufnu

My Feedback: (2)

What's wrong with HEET? It's just methanol, right? I mix it with glow fuel until I get around 10% oil content then mix the whole shebang with 2 parts gasoline.

For those that can't find 10/10 fuel, try Sig:
Link!

LHS doesn't have any, after I get back from my weekend trip I'll ask him if he can order some. If I can get my hands on some I'll get that, get some new gas, and mix up a new batch and see if that doesn't help any.

Wufnu

My Feedback: (2)

I'll try that next time, probably Monday. I always tried to hand start it first and when I got tired I tried the electric starter, but if there was excess fuel from the beginning I never gave it time to burn it out.

Wufnu

My Feedback: (2)

There is no choke that I can see. I'll take off that brass pipe he has attached to the carb, I honestly don't know why it's there, and give it a try.

captinjohn

Before you take the brass pipe off he carb....be sure what its for. Post a photo of what you have if you can. Capt,n EDIT for up-date... It sounds like the pipe is a velocity stack. If you have choke removed...plug the choke shaft holes.

jpanhalt

[/quote]What's wrong with HEET? It's just methanol, right? I mix it with glow fuel until I get around 10% oil content then mix the whole shebang with 2 parts gasoline.[/quote]

From the HEET website:

HEET contains special additives and methanol. When HEET is added to the gas tank, it sinks to the bottom and mixes with any water. Since both HEET and water are heavier than gasoline, they go to the bottom of the gas tank. HEET absorbs water and keeps it from freezing, and blocking the flow of gasoline through the gas line and fuel pump. When the vehicle is started, the additives, methanol, water, and gasoline are consumed during combustion inside the engine.

Could those "special additives" have anything to do with the balkiness? The manufacturer says it's OK for four-strokes, but warns against using in two-strokers. John

Wufnu

My Feedback: (2)

Suppose it's possible, since I don't know. I know I use it to cook with when I go camping and not only is the flame invisible in sunlight but there are no smells either. Either way, good racing alcohol would be the best choice if I can't get some 10/10 and probably cheaper per volume.

The brass pipe is just a pipe extension of the venturi. It's about 1.5" long and to look at the butterfly valve you have to look down this pipe. I don't have my digi cam, I've loaned it out to someone. The only thing I can think of it being is an extension to draw air from outside a cowl, but why would anyone want to do that? That's completely backwards.

buck1856

My Feedback: (49)

heres a pic of an engine i purchased.does it look like this.If it does its a persons way of making a velocity stack or some kind of tunnel ram or they did it to make it look like a piece of sophisticated ram air.dont know,this is the way i bought it and its the way im going to sell it.

Wufnu

My Feedback: (2)

Sort of. They didn'g glue/weld it into the hole like yours, they welded it to a plate and attached it with the two screws close to yours. It covers that whole side with the pipe sticking out like yours, only a bit further I think. I was going to remove it because I thought if the seal between the plate and the carb wasn't air tight then covering the pipe would have no affect as air could still get in. I don't see why it's needed, cowl pressure would be better anyways. Anyone know what these pipes do or are they just for show?

buck1856

My Feedback: (49)

On some engines somtimes a little of the fuel spray comes out the front of carb.A proper velocity stack keeps this fuel from coming out of carb and goes back into engine and also increases air flow.In order for yours not to work properly in my opinion you would have to have a visible space around the base.if theres any kind of a gasket under it i doubt if your leaking or sucking air.check all gaskets to see what they look like and see if your pulse hole is clear and the holes in gaskets and everything line up and arnt blocked or plugged.

ROOSTERLEW

Justin,

Velocity stacks do this and more...the key point to remember her is a"proper" velocity stack.

To make one properly takes one of two things. Either much scientific calculation, or a bit of experimenting.

The problem with most home made velocity stacks is that they are missing both and are mainly just what you said, for looks!
An improper inlet on a carb can wreak havoc on its airflow!
however, I would agree with buck, that shouldn't cause you to not be able to choke engine unless theres a visible gap.

In regards to your problem of why it won't start I know how to fix it.......
Place it in a box, ship it to Cap'n, have him play wif it, call Aeronuts and av8tor, dave, rysium and all the other smart guys...
Trade it for a dog......shoot the dog!
Cured