jimmy 1987

ok took my boat out useing a 10 ounc tank

ran it for about 6 mins the then came in

then went to go again started fine put it in the water did half a lap then died

and then it it again

any help????

running 26 omen full mod

pyro1

Back off the Hi needle just a bit. Worked for me. It might be leaning out at top end.
FYI Tony of Whobbies.com has a new segment/video on how to start & tune Zenoah engines.
best regards, Pyro1

kwiktsi

I was just messing with the carb on my blackjack to try to set the low speed by Tony's info and had no luck. With the needle anywhere near 1 1/2, it would not run and I never heard a "woowing" sound like he describes.]. I turned it in until it leaned and revved, then just until it was about to stall and then backed it out about 1/2 turn or so until it started running very rough and then kept going back and forth until I found a good midway point between the two- does that sound about right? I am running 6oz/gal and it is set so that it lets out the slightest bit of smoke at idle.

Now, with setting the high end- is it ever supposed to "clean out" and scream up top, or leave it so that it still has a slight "gurgle" to it? I have it a bit on the rich side so it never sounds like it is screaming, but it isn't sluggish either. I wonder if I can lean it a touch more without hurting things.

martno1fan

also check your tank vent if its not working pressure build up will starve the motor of fuel.

rcboateric

that's why I'm keeping away far from those hard tanks mate.

Dan S

Joe,

what engine (stock or Mod) and what carb?

Dan.

kwiktsi

Stock Zen 26 (blackjack 55) with oem carb as well. I just got back from running the boat actually and it seems pretty good. I had to open the low end a bit since it had a hesitation when nailing it from a dead stop. Richened it up and that went away, just idles a bit rougher, so I had to turn up the idle a bit. Just seems to run a little rough at lower RPM's (like 1/4 throttle cruising). Is this normal, or are they supposed to be smooth?

The high end screw, I backed out just until it ran a bit "garbly" on top (on the water, of course) and then turned it in about 1/4, made 6-7 laps and the plug was good, but I backed it out a touch from there just to keep is safe. Seems to run good, this boat is just pretty slow compared to what I am used to, so I keep wondering if something is wrong haha.

Also- Dan, just in case you missed it- I'm not the OP of this thread. Just pointing it out to make sure he doesn't get ignored by accident .
Joe

PEERPSI

Just played with my boats tuning tonight. Zenoah 26 in a Blackjack 55. Now a little about my background, electronics technician,master electrician and millwright. I've also built several cars with aftermarket ECU's and forced induction, turbo and superchargers. My point, instrumentation! None of this it sounds good.

So how to do this with a weed wacker motor? Ideally exhaust gas temperatures is what you want to measure, how to do that practically? The only thing I could thing of was a digital RPM gauge to set idle and high rpm mixture. Practical way of installing a digital RPM gauge? Used a Fluke meter set to hz metering between the engine block and kill switch line. Now hz is not RPM but RPS, for RPM multiply by 60. This seems to have helped me setup idle.

Tuning the high is resulted in a net gain of 10 hz or 600 RPM for a total of 21000 RPM. Now this was of course dry dock tuning so now water load just the drivetrain.

I'm thinking I need to get someone to hold the boat while I repeat this in the water.

How are you tuning your engines?

I also noticed that the fuel bulb is full of bubbles and not completely full like it is on my buggy with a similar motor and carb. I thinking this isn't good. Any ideas?

Seems to run good though!

kwiktsi

I too have built several high performance cars over the years, mostly turbo'd. My last modded daily driver was a 2005 GTO with an APS twin turbo setup- built and tuned by myself. 795hp/806 torque at the rear wheels on pump gas with meth injection. My opinion- you're overcomplicating this . These are very simple motors to tune. If you wanted to go that far, you'd get more out of a wideband than a tach anyway.

Dan S

Thanks Joe,

I don't know what carb comes with the BJ 55,

I know its a walbro but what number?

257?

644?

for a 257 you start with the needles at 2 for the L and 1 for the H,
but I am not sure for the 644 and the others.

Dan.

PEERPSI

But complicating it is what I do!

In a perfect world I'd be able to by 1/5 scale WBO2 sensors, fuel injectors and throttle bodies! Of course then I'd need a 1/5 scale fuel pump as well.

Hmm, maybe I am overcomplicating it!

PEERPSI

Walboro WT-644. Manual also gives the default factory settings. My point is that I can't leave well enough alone and I'm curious to see who else has and how they've ventured down the dark path to maximum power!

glennb2006

A long way down the path is the answer to the question above.
However, you are not going to get any major gains from adjusting needles on the carb., you will of course get the motor running to the best of it's ability.

For more power, you need to go down the route of alternate port timings, tuned pipes and most likely larger (or more free flowing) carbs. And lighter piston.


Lots to be gettign on with there I think.

Glenn

OLD_SLOW and in the WAY

the low speed needle controls things up to about 2/3's throttle and the high speed takes over from there on up. you need to dump all the fancy schmancy digi stuff and learn the old skewl way to tune ... by reading the plug and being able to hear when an engine is going flat ( too lean)
set low needle at 2 turns to start and 1 1/2 on the high, run the boat and only adjust the high needle 1/8 turn at a time

kwiktsi

I'm sure the future holds plenty of that, but for now- time to get your hands dirty and get oldschool . Hell, even with all the proper logging equipment, I still did some of my GTO tuning by sound and reading the plugs.

As for the carb- is a 257 a decent upgrade for this, or is there a better choice? I'll probably be doing a ported jug and lightened piston as well. Thanks.
Joe

nvs motorsports

Eagle Tree makes telemetry that you can put on your motors it measures rpm, temp, ex temp, electrical , and speed also can down load a 10 minute run bit like a dyno on water

PEERPSI

Data logging now you're talking my language. Going old school, been there my Vette was carburated, means leaving well enough alone. It's not just about standing in the water watching the boat for me. I intend to fully plunge myself into that slippery ride down the upgrade slope!

Anyone using this telemetry setup?

doomracing

can you do a pinch test to set the low needle like ya can on nitro motors?

for those of you who are scratching your head, and saying *** here is how ya do a pinch test:

1) fire it up, and hit the throttle a few times to clear it's throat.
2) pinch off the feed line to the carb, and count 1 one thousand 2 one thousand 3 one thousand.
3) if the motor quits in less than 3 seconds the low end is too lean. over 3 seconds it's too rich.

this will get you really close on a nitro low needle. a hour or 2 +/- more fine tuning mite be needed, but the motor won't bog, or stall when you take off. works great on cars. mite it work on gas motors? i'll have to give it a try, and report back.

MrMikeG

You can't tune a gas motor out of the water, you need to load the engine. But hey, pinch away if it makes you feel good!

doomracing

well that's my question. will it work? works fine for nitro cars with no load.

RKS1949

I tried to run my Miss Elam Hydro today. This is the third boat that Horizon has replaced for me,and it ran as BAD as the rest![:@] This is my first GAS boat,and I'm having a hard time getting it to run. I think it and the Black Jack 55's have the same motor in them. My boat seems to want to run lean. I have to adjust the needles way rich to get it to keep running. I was also told to run a mixture of 16:1 instead of the manual recomended mixture of 32:1. I finally decided that the boat was "sucking air" into the fuel system some where. I removed the stock tank,fuel lines,and carb,intake, to check them out for leaks. What I found was that the intake manifold was warped,and it didn't look like it had sealed the gaskets well. I've replaced the fuel lines with trylon(Ithink that's how you say it) lines secured all the connections,trued up the intake surfaces,and used gasket sealer on all the gaskets. I started it up this evening,and tried Tony's method of setting the LS needle. I never heard any "whooing" but it did diewhen I went too lean. I then restarted the motor,turned the LS needle in until it was too lean,and backed it out 1/2 turn. It will idle for ever,and not load up,so I may be close? I tried the "ZENOAH" manuals settings of 1 turn out LS ,and 1 5/8 HS and it runs like crap dying in the turns every time![:@] I've heard of all kinds of settings,oil mixtures,octane ratings,ect. and NONE match the Motors recomended manual specs. I'm determinded to make this boat run! All of my glo powered boats run better than this gas boat,and I thought they (gas boats) were supposed to be less fussy,to setup and run! Another "symptom" the boat has is to die after running down the straits at full throttle,as soon as you let off the throttle! I've had Zenoah engines in my planes,and NEVER had trouble getting them to run like this one. I see videos of this boat tearing up the water on you tube,so some one "knows how to make them run". A setting of 2 out on the LS needle,I haven't tried yet (but I will). This motor is Busti'n my chops![:@] But sooner or later I'll get it to run! Ron

boogermancan

no two carbs are the same. so tuneing it like your buddys and his or hers is still faster that is how come ... 2 gas over glow fule . you burn more glow then gas .. you need less fule makes tuneing that much harder next if you burning less this means 1 little pice of trash in you fule is going to give you a pain . a good filter to stop the trash from getting in the needle and cloging your flow . but this is stuff you allready new so pay no mind to my babbling's imho it never hurt to run a little fat on the fule

RKS1949

Yeah,I like to run a Little "FAT" on all my motors. I'd just like to be able to get this one to run well period! So Far it's been launch,then retrieve,launch[:@] Ron

RKS1949

Does the boat run well at these settings? I'd be happy to get one tank of fuel through my Miss Elam,without it dying,or stalling on me. Ron

dicko

Dying after a WOT run sounds like it's a bit lean - starving for fuel when you back off. Have you had a look at the colour on the spark plug? You want a nice tan/coffee colour. Grey or white is too lean, black is too rich.

I found that running gas was sooooo much easier than running & tuning my nitro engines. Hopefully you get teh bugs sorted out soon & can appreciate the swap.