tuning and cooling a zenoah 23marine in place

[johnbrown]

i own a miss budweiser 1/8 scale hydroplane with a zenoah 23marine engine. my question is this>
is there anyway that i can tune the engine while in a closed container and still be able to cool off the engine with water? right now it seems that the only way that water flows through the engine and pipe is if i run it through the water. looks like it needs to be moving for water to flow. is there a pump i could buy or something .? i would like to tune it in an enclosed environment so i dont screw up the boat or hurt someone.


thank you !:(

[Doubledog]

When you say tune, what exactly are you talking about? What do you wish to accomplish by doing so?

Yes, you can run an engine out of water buy connecting several things to it. I've ran a garden hose connection to the cooling head via small waterline connection. Even took a three liter bottle of water, ran small waterline & let gravity feed it to the head. Sort of like an IV setup. & lastly, for a water pump, I've diconnected the water line and put it in a bucket & let the water pull from there. Thats how I broke in my last engine for the first tank. (long story).

Keep in mind that a boat running with no load is not going to tune well at all & you will most likely waist your time. Setting the prop in a bucket or pool still isn't enough as if it were running in an open lake.

The best thing to do is find the proper needle settings for a starting point & go from there. I usually start at 1.25 turns open on both the high & low needles.

[johnbrown]

im running it in place and tuning it with load. i dont want to have it stall and then try to retrieve it all day. i know they sell mini water pumps but where do i find them? i dont want to blow the engine up.

[Doubledog]

Gas engines are different from nitro. Stalling doesn't occur nearly as often and you should be quite pleased once you get it going. Just start with the needles 1.25 - 1.5 open on both and go from there.

You say running it in place with a load? How do you plan on putting a load on it? Again, it will not tune like you think and could be quite dangerous/expensive in the end. Why again? To break these engines in doen't require bench running. Just be judicious with the throttle. Run up to half for a few laps to let the heat build & then bring it in to cool off to ambient temp. Run again a few laps & cool completely down (ambient temp). Do that maybe the first tank.

I like to ask folks how did you break in your gas weedeater? Have you ever done that with one? Doubt it. Most folks put gas/oil mix in & let 'er eat right? How long has the weedeater served its purpose & ran strong? Probably more than you'll ever run this gas boat.

Another note is running a clutch in a Hydro? Have you done this before? They generally don't like to start from a stand still and gradually move forward. They like to be tossed pretty aggressively to get going.

Waterpumps can be bought most any hobby shop. First one that comes to mind is http://whobbies.com/ or Bonzi Sports.

Let us know how it turns out. I'm getting ready to install a pump in my boat this weekend & will post pics of the install. Check out the build thread in the General Discussion forum.

Later,
Jamie

[Burkey1000]

If youve got the time, run through about half to one tank of caster based two stroke oil and be gentle with it then slowly increase the speed. keep it varied as much as you can. going to slow puts just as much load on the engine as full throttle so make sure its running quick enough. The reason for the castor is modern two stroke oil is so good at its job, it does not let the ring bed in properly and glazes the bore. Once done with the caster continue as Jamie said with a good synthetic based oil. Run it to temp and let it cool down for a couple of tanks then you should be good to go. Might just be me but when the thing is ready, i swear i can hear a change in the engine pitch, sorta gets a little higher all of suden. Found this on all my motors, could be i got bat ears or something :D. Then i know its ready to rip. Some seem to take a little less time than others too. JM2P.:)

[johnbrown]

does anyone know where i can find a mini or micro water pump that runs on 3 volts max.?

[Doubledog]

Just run a normal pulse water pump. Its too easy and you don't need more. The only thing the pump is for is for idling. at speed, its being by passed anyhow.

[mjmsprt40]

I'd like a little clarification on the part where you're running the engine in a closed container. It sounds almost like you're saying you'd run it in your garage. Please don't, these things produce CO like any other running gas engine and you'll be overcome before you know you're in trouble.

Otherwise-- listen to Doubledog. He's right. Gas engines are remarkably easy to set up. Take it down to the lake, set the needles as DD has told you and start from there. You'll probably be running rich at first, this is good. Lean it in after you get a few tankfuls of fuel through her, maybe an eighth of a turn on your high speed needle at a time. Set the low speed needle for a dependable idle-- that's all you're worried about there, that and a clean transition through mid-range.

I've had my Homie die on me, requiring a retrieval, exactly twice. Once was on account of running out of fuel, the other time was on account of a radio glitch that shut down the throttle. Otherwise, it doesn't shut down until I shut it down.

[Muddy]

G'day Guys,

this is exactly the next question I was going to ask...I will definitely have to take Mohammed to the Mountain.
I was going to try tune my mates enforcer boat at home, with water flowing through the motor's cooling system.
Looks like it won't do me any good, huh?

I'll have to take my towel, as I'm sure I'll have to go for a few swims before I'm done!

[Doubledog]

No Muddy, its not that difficult with the gas engines. But take a fishing pole along just in case:D

What carb is on the engine? Get the needle settings pretty close & go from there.

Rich Runs
Lean Dies

[Muddy]

Thanks, DD
It's a Walbro - not sure what the mumber/type is.
I have H = 1.5 turns
L = 1.25 turns
I had to make a choke lever from an old servo horn.
I'm sure the choke was partially still on
Now it's able to be turned on and off.
It starts, runs, and responds well to "stabbing" the throttle, but it dies at idle sometimes (after running WOT for a few seconds)
I'll just have to try my luck on a body of water

Happy New Year everyone!

[Doubledog]

How low do you have the idle set?

They don't like to putt-putt around ya' know. If its got a clutch on, set the idle so the clutch is barely turning the prop. Water pressure will usually stop it.

[Muddy]

How low do you have the idle set?

They don't like to putt-putt around ya' know. If its got a clutch on, set the idle so the clutch is barely turning the prop. Water pressure will usually stop it.

Thanks, mate; didn't know that - I'm used to tuning land crawlers (cars) and a putt-putt idle is a good thing there.
I had the idle higher when I first set the needles, (something I always do to stop stalls when setting L needle) and I'm sure there wasn't much trouble this way. I'll give it a go!:):):wave:

[skyterrapin]

Just run a normal pulse water pump. Its too easy and you don't need more. The only thing the pump is for is for idling. at speed, its being by passed anyhow.

Wonder if you chaps can assist. I have just bought my second gas/petrol enigine second hand and it came with a pulse pump. I have never used one of these before. Can anyone let me know how I plumb one of these in to provide cooling whilst the boat is stationary please? It is a square pump with 3 nozzles. Blowing through them I can get air to pass from one and out of another.. but not back the other way (makes sense) but the third nozzle seems to do nothing????????

[Doubledog]

try this.

[Doubledog]

more...

http://image2-4.rcuniverse.com/e1/forum/upfiles/180989/To43684.jpg

http://image2-0.rcuniverse.com/e1/forum/upfiles/180989/Rw58490.jpg

[Doubledog]

last one...

http://www.rcuniverse.com/forum/m_6189449/anchors_6189449/mpage_1/key_Water%252Cpump/anchor/tm.htm#

[skyterrapin]

My word... that was quick! That is brilliant , thanks so much.
My engine has a tap off in the intake manifold which I suppose I use instead of the cranckcase pressure as per diagram?


Whoops.. think my question crossed with your additional diags!

[Doubledog]

Happy to help & good to meet new folks. :)

[Hydro Junkie]

I'm still trying to figure out why everyone seems to think it's best to run multiple tanks of fuel through on the beach? I blew up a nitro motor doing that and dont' see the point with a gasser. One other thing I don't see the point in is putting a clutch in a hydroplane. If it was my boat, first FOUR things I would do are:
1) move the radio gear into the cockpit area
2) move the fuel tank under the deck on the right side of the engine
3) take the clutch and throw it as far out into the lake as I could
4) install a balanced, sharpened and polished Octura 465 or 470 prop

[Doubledog]

I don't see the point in is putting a clutch in a hydroplane.

If/When I decide to build one of my Zipp Kitt Rivett's, I'll put a clutch in as well. Its a matter of choice and because I run alone once in a while. Not all of us belong to clubs where you've got the extra hand to help. ;)

Also, note that the benefits out-weigh the consequense ie.. so I don't get 95mph like some guys, I'll settle for 92 & have an easier boat to play with. LOL. :p

[mjmsprt40]

I'm going to side with Hydrojunkie about running several tanks of fuel through an engine on the beach. It doesn't help and may, in fact, be bad for the engine to do that. First, you're running the engine with NO LOAD that way so the engine won't wear in properly. The airplane guys get away with it because they're swinging that big stick of wood on the front and that loads the engine. Our boat propellers are barely noticed on the beach, they just don't move enough air to do you any good. Second, going back to that no load condition-- bet you over-rev the engine before you realise it. That's where the damage is done, and once done it's permanent. Third, it's a waste of perfectly good (and I might add increasingly expensive) gas/oil mix. That fuel can be put to better use on the water where you can trim the engine under actual running conditions and get it race-ready that much quicker into the bargain.

[Hydro Junkie]

Doubledog, the reason I would deep six the clutch isn't obvious to most. I have seen a gas hydro literally go out of control when the engine RPM got too low and the clutch released. Since the rear of the boat is supported by the prop, the sudden loss of that lift dropped the transom and caused the boat to blow over. In corners, the sudden loss of the propwalk effect caused the boat to turn unpredictably and sent it off in the wrong direction when the clutch re-engaged. To take it one step further, around 95% of hydros require a throw launch and not the drop and mash the throttle start, making the clutch's use that much more problematic. Unless you plan on running full throttle the entire time, loose the clutch and water pump since they are just added un-needed weight