BJ55 Tuning help needed  
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All Forums >> RC Boats >> Speed - RC Gas Boats >> BJ55 Tuning help needed
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BJ55 Tuning help needed - 8/31/2008 9:26:30 PM   
birdy233


 

Posts: 31
Joined: 1/22/2005
From: Frisco, TX, USA
Status: offline 		My BJ55 ran perfect, three pulls then idled perfect, ran about 42 mph stock, never sputtered or died.

I flipped the boat over last weekend for the first time, it sputtered and and died while sitting upside down. Brought it in, drained the water that got in the boat. When I got home, drained the tank, had a bit of water in the motor as I pulled the plug and turned it over, had some water in it. Let it dry out and now it will not run right. Cleaned the carb, new plug, still no luck. It fires over but quickly dies. Have gotten it to stay running for a minute or so, had to set the low needle way out like four turns, but still winds up stalling. Any thoughts on what to do?

       Post #: 1

RE: BJ55 Tuning help needed - 8/31/2008 10:11:30 PM   
rcboateric


 

Posts: 787
Joined: 7/23/2008
From: henderson, NV, USA
Status: online 		sometimes my boat would flip over on windy days, never had a problem like yours, you might re-set the needles back to original, and make sure there no air bubbles in the fuel.

(in reply to birdy233)
       Post #: 2

RE: BJ55 Tuning help needed - 8/31/2008 10:27:42 PM   
birdy233


 

Posts: 31
Joined: 1/22/2005
From: Frisco, TX, USA
Status: offline 		yep, fresh new fuel, just blew out the needles again, reset back to factory settings, seems to be ok right now. need to run it by the lake in the morning to verify

< Message edited by birdy233 -- 8/31/2008 10:28:04 PM >

(in reply to rcboateric)
       Post #: 3

RE: BJ55 Tuning help needed - 8/31/2008 10:35:24 PM   
rcboateric


 

Posts: 787
Joined: 7/23/2008
From: henderson, NV, USA
Status: online 		your engine will be fine.

(in reply to birdy233)
       Post #: 4

RE: BJ55 Tuning help needed - 9/1/2008 12:06:15 AM   
dicko



Posts: 2575
Joined: 2/4/2004
From: Adelaide, AUSTRALIA
Status: online 		Next time you flip it & suck water, get the engine started straight away, the heat will evaporate any water in the engine & the fuel will lubricate the inside & stop it from corroding.

_____________________________

The answer is always more power.

(in reply to rcboateric)
       Post #: 5

RE: BJ55 Tuning help needed - 9/1/2008 1:04:26 AM   
kwiktsi


 

Posts: 513
Joined: 5/31/2004
From: Milford, PA, USA
Status: offline 		42mph stock?? Stock prop as well? Where do you have your strut height set to? Just curious because while I haven't GPS'ed it, there is no way mine looks anywhere near 40+ mph lol. Might be the size throwing me off, but I'd estimate low-mid 30's by eye. I gotta get my GPS in there and get some numbers on it. My electric cat is ~53mph and spanks the Blackjack like it's standing still- looks like a lot more than just a 10mph difference.

(in reply to birdy233)
       Post #: 6

RE: BJ55 Tuning help needed - 9/1/2008 2:55:47 PM   
birdy233


 

Posts: 31
Joined: 1/22/2005
From: Frisco, TX, USA
Status: offline
quote:

ORIGINAL: kwiktsi

42mph stock?? Stock prop as well? Where do you have your strut height set to? Just curious because while I haven't GPS'ed it, there is no way mine looks anywhere near 40+ mph lol. Might be the size throwing me off, but I'd estimate low-mid 30's by eye. I gotta get my GPS in there and get some numbers on it. My electric cat is ~53mph and spanks the Blackjack like it's standing still- looks like a lot more than just a 10mph difference.



All stock except balanced and sharpened stock prop. Use a garmin foretrex gps, works great picked up on ebay for $45. I use it as my tuning tool. Stock prop from the box I ran 38.8, after prop and adjusting strut up a bit got just over 42. It has gotten faster the more tanks I ran, when almost new it was running around 35-36 mph.

(in reply to kwiktsi)
       Post #: 7

RE: BJ55 Tuning help needed - 9/1/2008 3:21:56 PM   
kwiktsi


 

Posts: 513
Joined: 5/31/2004
From: Milford, PA, USA
Status: offline 		Wow, very nice. I have to GPS mine next time out. To me it looks slower than that, but it could be the size throwing it off. My smaller boats look like rockets at 40+ due to their size!

As for your running problem, if everything was good before and all that happened is it flipped, it has to be water in the lines, carb or motor still. I flipped mine and it gurgled along upside down until it sucked water and stalled. Pulled it in, yanked the plug and pulled it a bunch of times to get the water out. Dried the plug with a lighter, put it in and it fired up stalled- pulled plug again to dry it and blow the water out about 2 more times until it started, ran rough for a few seconds and and then ran perfectly from then on- even using the same tank of gas.

(in reply to birdy233)
       Post #: 8

RE: BJ55 Tuning help needed - 9/3/2008 2:23:47 AM   
philip clemmons


 

Posts: 29
Joined: 8/26/2008
From: sandston, VA, USA
Status: online 		Mine runs 42-43 every hit. Its completely stock with a balanced stock prop. Strut is dead flush. I tried as high as 1/8" up with no noticeable change.

(in reply to kwiktsi)
       Post #: 9

RE: BJ55 Tuning help needed - 9/3/2008 5:27:57 AM   
kwiktsi


 

Posts: 513
Joined: 5/31/2004
From: Milford, PA, USA
Status: offline
quote:

ORIGINAL: philip clemmons

Mine runs 42-43 every hit. Its completely stock with a balanced stock prop. Strut is dead flush. I tried as high as 1/8" up with no noticeable change.


Hmm, I'll definitely have to GPS mine, it *looks* slower than that to me, but it is possible it's just the size throwing me off like I said. As for your strut being dead flush- are you talking about flush with the bottom of the sponsons? If so, did you have to open the slot up in the strut to get it down that low? Mine will not go that far down, I'll have to open it up a bit but I do have it as low as it will go with a couple degrees up thrust to it to try to loosen it up on the water a bit.
Joe

(in reply to philip clemmons)
       Post #: 10

RE: BJ55 Tuning help needed - 9/4/2008 5:26:02 PM   
lineman1221


 

Posts: 91
Joined: 4/16/2006
From: La Puente, CA, USA
Status: offline 		Joe, i think your best bet is to gps your boat. if you think about it, a 1/10 scale sedan running at 40 mph would appear to run faster than a full size vehicle due to its size. the guy that i sold my BJ 55 bought another one after he crashed the one i sold him and that one runs low 40's all day long also. its fully broken in zen with acouple of gallons ran through it. that might have something to do with it also if yours isnt quite broken in yet.

Raymond

_____________________________

its better to remain silent and be thought of as a fool than to speak and remove all doubt

(in reply to kwiktsi)
       Post #: 11

RE: BJ55 Tuning help needed - 9/5/2008 12:00:58 AM   
philip clemmons


 

Posts: 29
Joined: 8/26/2008
From: sandston, VA, USA
Status: online
quote:

ORIGINAL: kwiktsi


quote:

ORIGINAL: philip clemmons

Mine runs 42-43 every hit. Its completely stock with a balanced stock prop. Strut is dead flush. I tried as high as 1/8" up with no noticeable change.


Hmm, I'll definitely have to GPS mine, it *looks* slower than that to me, but it is possible it's just the size throwing me off like I said. As for your strut being dead flush- are you talking about flush with the bottom of the sponsons? If so, did you have to open the slot up in the strut to get it down that low? Mine will not go that far down, I'll have to open it up a bit but I do have it as low as it will go with a couple degrees up thrust to it to try to loosen it up on the water a bit.
Joe

Top of strut dead even with mounting bracket (this is the as shipped set up)

(in reply to kwiktsi)
       Post #: 12

RE: BJ55 Tuning help needed - 9/5/2008 12:40:50 AM   
kwiktsi


 

Posts: 513
Joined: 5/31/2004
From: Milford, PA, USA
Status: offline
quote:

ORIGINAL: lineman1221

Joe, i think your best bet is to gps your boat. if you think about it, a 1/10 scale sedan running at 40 mph would appear to run faster than a full size vehicle due to its size. the guy that i sold my BJ 55 bought another one after he crashed the one i sold him and that one runs low 40's all day long also. its fully broken in zen with acouple of gallons ran through it. that might have something to do with it also if yours isnt quite broken in yet.

Raymond


Yeah, I agree- my 27" long x 7" wide electric looks like a missile at 41mph- my 31" cat looks absolutely ballistic in the mid 50's- especially since it only sits a couple inches tall! I'm sure it is just perspective due to it's size.

(in reply to lineman1221)
       Post #: 13

RE: BJ55 Tuning help needed - 9/5/2008 12:43:43 AM   
kwiktsi


 

Posts: 513
Joined: 5/31/2004
From: Milford, PA, USA
Status: offline
quote:

ORIGINAL: philip clemmons


quote:

ORIGINAL: kwiktsi


quote:

ORIGINAL: philip clemmons

Mine runs 42-43 every hit. Its completely stock with a balanced stock prop. Strut is dead flush. I tried as high as 1/8" up with no noticeable change.


Hmm, I'll definitely have to GPS mine, it *looks* slower than that to me, but it is possible it's just the size throwing me off like I said. As for your strut being dead flush- are you talking about flush with the bottom of the sponsons? If so, did you have to open the slot up in the strut to get it down that low? Mine will not go that far down, I'll have to open it up a bit but I do have it as low as it will go with a couple degrees up thrust to it to try to loosen it up on the water a bit.
Joe

Top of strut dead even with mounting bracket (this is the as shipped set up)

Gotcha. I typically set my cats up with the strut flush or just above the bottom of the sponsons. The way it sits in the bracket is kind of unimportant as bracket height can vary from boat to boat. Best to measure from the sponsons- with the boat sitting flat on a table, measure the height of the strut off the table surface. Thanks for the info though, I'll go look at where mine is sitting in the bracket. I know it is as low as it will go though.

(in reply to philip clemmons)
       Post #: 14

RE: BJ55 Tuning help needed - 9/5/2008 2:11:40 AM   
philip clemmons


 

Posts: 29
Joined: 8/26/2008
From: sandston, VA, USA
Status: online 		Just got it this weekend, so I have had limited time and this is my first boat. It was just a good reference to use for tuning sake......................

Seems to be confusion on which way to move the strut to get more speed......................

Any takers?

(in reply to kwiktsi)