Bad luck
#1
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Bad luck
I think I don’t have luck with boats.. every time I try to improve my boat it get worth…. I bought new Zenoah 26cc, I install it and run it with no problem then I decided to make some modification then I changed the carburetor to 257, Installed clutch and Walbro water pump, change all cooling tubes , water pickups and new fuel take with screw cap instead to Sullivan Tank.
Today I give it a try, engine start after 3 pulls thanks to advise from stoddy and Paul M whom they direct me how to start engine in absence of primer bulb. But the engine lost power completely and what ever throttle I put the boat move 5 mph, I played a lot with carburetor needles but no way, I checked fuel tank and I closed the return fuel tube but no success also,
1- I made plus fitting exactly as Justaddwata post ( http://www.rcuniverse.com/forum/m_61...anchor/tm.htm# ) and I manage to do it perfectly.
2- I used Tygon tube ( length 16’) to connect pulse fitting to water pump.
3- The engine ideal very good.
4- Water mump and new water pickups working excellent because water came out outlets as fountain.
5- I played ignorance with carburetor needles because I don’t have factory setting. But I start with 1 ½ for H and 1 ¼ for L.
long time I read post about pulse fitting and carburetor setting also about ventilation of screw cap fuel tanks but I can’t remember where and I don’t know what happen… can anyone help me please? I’m really depressed
Today I give it a try, engine start after 3 pulls thanks to advise from stoddy and Paul M whom they direct me how to start engine in absence of primer bulb. But the engine lost power completely and what ever throttle I put the boat move 5 mph, I played a lot with carburetor needles but no way, I checked fuel tank and I closed the return fuel tube but no success also,
1- I made plus fitting exactly as Justaddwata post ( http://www.rcuniverse.com/forum/m_61...anchor/tm.htm# ) and I manage to do it perfectly.
2- I used Tygon tube ( length 16’) to connect pulse fitting to water pump.
3- The engine ideal very good.
4- Water mump and new water pickups working excellent because water came out outlets as fountain.
5- I played ignorance with carburetor needles because I don’t have factory setting. But I start with 1 ½ for H and 1 ¼ for L.
long time I read post about pulse fitting and carburetor setting also about ventilation of screw cap fuel tanks but I can’t remember where and I don’t know what happen… can anyone help me please? I’m really depressed
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RE: Bad luck
the 257 is a good carb its what most use in fact,try the settings it says on the website that should get you started and running .Also does your tank have a vent in the cap? make sure its not blocked.
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RE: Bad luck
Thanks martno1fan , I will try this setting… for tank…yes my tank have vent and I will check it, also the tank have return tube but I close it... Shall I open it to make good ventilation
#8
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RE: Bad luck
ORIGINAL: irenaslavo
I read that water pump should close to engine but I don’t know if 16” is long distance or good distance? Any advise ?
I read that water pump should close to engine but I don’t know if 16” is long distance or good distance? Any advise ?
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RE: Bad luck
needle settings for 257 carb are 2turns on low needle and 1 turn on high should run ok on that setting.
also if the motor is revving and the boat is only doing 5mph move your strut or stinger up lifting the prop out of the water or try a different prop
had the same problem myself with my apache thought it was the clutch bought a new one still did the same.
changed the 3 blade prop for a 2 blade and of it went so i shouldjust have a look at those before you go buying carbs
the 257 is a good carb
also if the motor is revving and the boat is only doing 5mph move your strut or stinger up lifting the prop out of the water or try a different prop
had the same problem myself with my apache thought it was the clutch bought a new one still did the same.
changed the 3 blade prop for a 2 blade and of it went so i shouldjust have a look at those before you go buying carbs
the 257 is a good carb
#10
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RE: Bad luck
Thanks gentlemen, I tuned carburetor 2 turns for low and one turn for H... engine working perfectly but I didn’t try full throttle because I was worry since I read posts about carburetor starvation at high speed with water pump fittings in the carburetor. Shall I open L needle a bit to permit more fuel OR no problem.
Also I would like to know if there is big difference between stock Zenoah carburetor, WT 257 and WT 813 and why better to replace stock carburetor by 257 or 813
Also I would like to know if there is big difference between stock Zenoah carburetor, WT 257 and WT 813 and why better to replace stock carburetor by 257 or 813
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RE: Bad luck
the 644 stock carb is bomb proof and has the same bore as the 257 and 813. only difference is a choke and primer bulb. i hate the 257 its a son of a gun to tune and hold a tune. i use a 644 on all my fully modded pum260's as well as my stock ones. i remove the choke and fill the holes with quick set JB WELD. its bacally a 257 thats easy to tune and hold a tune. i got 5 257's in a box want to buy them..LOL..
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RE: Bad luck
ORIGINAL: stuch
the 644 stock carb is bomb proof and has the same bore as the 257 and 813. only difference is a choke and primer bulb. i hate the 257 its a son of a gun to tune and hold a tune. i use a 644 on all my fully modded pum260's as well as my stock ones. i remove the choke and fill the holes with quick set JB WELD. its bacally a 257 thats easy to tune and hold a tune. i got 5 257's in a box want to buy them..LOL..
the 644 stock carb is bomb proof and has the same bore as the 257 and 813. only difference is a choke and primer bulb. i hate the 257 its a son of a gun to tune and hold a tune. i use a 644 on all my fully modded pum260's as well as my stock ones. i remove the choke and fill the holes with quick set JB WELD. its bacally a 257 thats easy to tune and hold a tune. i got 5 257's in a box want to buy them..LOL..
#14
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RE: Bad luck
257's are the easiest to tune, that is why everybody uses them. 644's suck, they last about one year then they are junk, they go out of tune and you can never get them back. For $25 brand new the 257 is the best improvement you can buy for your engine.
The settings are 2 on the low and 1 on the high, you might have to lean the high needle a little depending on your altitude but that is it. Remember both the high and low circuits are open at wide open throttle so basically your 3 turns out total, the same as your running 1.5 on both needles! Don't worry about being too lean on the top end, these engines produce the most power when the carb is set slightly rich.
The settings are 2 on the low and 1 on the high, you might have to lean the high needle a little depending on your altitude but that is it. Remember both the high and low circuits are open at wide open throttle so basically your 3 turns out total, the same as your running 1.5 on both needles! Don't worry about being too lean on the top end, these engines produce the most power when the carb is set slightly rich.
#15
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RE: Bad luck
Thanks very much gentlemen …. In France they are selling stock Zenoah with 644 and replace carburetor after 3 weeks because I was thinking it will gives better performance accordingly I can’t judge about durability of 644… the problem I faced because I tuned 257 same as 644 but thanks to martno1fan and stoddy , I tuned 257 and engine working good.
I heard from French racers whom they are using top end racing engines and sometimes they practicing with stock Zenoah that WT 813 is better than 644 -257, it gives better acceleration and they are using them on stock and modified engines, also they are using champion RZ7C plugs and they never use NGK normal or Iridium spark plugs although I read many post recommended NGK.
I’m think to order WT 813 and give a try.
I heard from French racers whom they are using top end racing engines and sometimes they practicing with stock Zenoah that WT 813 is better than 644 -257, it gives better acceleration and they are using them on stock and modified engines, also they are using champion RZ7C plugs and they never use NGK normal or Iridium spark plugs although I read many post recommended NGK.
I’m think to order WT 813 and give a try.
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RE: Bad luck
ORIGINAL: MrMikeG
257's are the easiest to tune, that is why everybody uses them. 644's suck, they last about one year then they are junk, they go out of tune and you can never get them back. For $25 brand new the 257 is the best improvement you can buy for your engine.
The settings are 2 on the low and 1 on the high, you might have to lean the high needle a little depending on your altitude but that is it. Remember both the high and low circuits are open at wide open throttle so basically your 3 turns out total, the same as your running 1.5 on both needles! Don't worry about being too lean on the top end, these engines produce the most power when the carb is set slightly rich.
257's are the easiest to tune, that is why everybody uses them. 644's suck, they last about one year then they are junk, they go out of tune and you can never get them back. For $25 brand new the 257 is the best improvement you can buy for your engine.
The settings are 2 on the low and 1 on the high, you might have to lean the high needle a little depending on your altitude but that is it. Remember both the high and low circuits are open at wide open throttle so basically your 3 turns out total, the same as your running 1.5 on both needles! Don't worry about being too lean on the top end, these engines produce the most power when the carb is set slightly rich.
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RE: Bad luck
ORIGINAL: stuch
doesn't the 813 have an acllerator pump in it also???
ORIGINAL: dicko
the 813 is the same as the 257, except with a bulb primer.
the 813 is the same as the 257, except with a bulb primer.
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RE: Bad luck
I’m a little confused, 1 on the high 2 1/2 on the low or 1 on the high 2 on the low, and I believe opinions regarding durability not performance… I replaced 644 with 257 because I through 257 gives better acceleration and now I’m thinking about 813 because I saw many racers using them and tune at 1 ½ Low and 1 1/4 high then how 257 and 813 are them?
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RE: Bad luck
have a look at this link Mart posted at the top of this thread.
http://bonzisports.com/carbs.html
it shows the differences between each of the carbys. at the bottom of the page it shows the baseline needle settings for each carb. the settings will change slightly as the engine runs in & also on alititude, air pressure & humidity.
http://bonzisports.com/carbs.html
it shows the differences between each of the carbys. at the bottom of the page it shows the baseline needle settings for each carb. the settings will change slightly as the engine runs in & also on alititude, air pressure & humidity.
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RE: Bad luck
@ 2550' above sea level we run 2 on the low and 7/8 after break in on the high. wt-257. Mopartybob has one of my thinned and modified 257's on his mild mod zen and has yet to complain about tune issues.