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Old 04-27-2012, 05:33 PM
  #51
RJStrickJR
 
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Ok, I have an honest good ole question. I have a 3W120 on a 35% extra 260, 28-10 prop. I am having a hard time starting it up. at first I thought it was flooding out but when I pulled the plugs out they were dry. This is after gas is running out of the carb. I put the plugs back in and try again. Same thing, no fire and gas running out of the carb. I walk away and let it sit for a few minute go back and flip it 2-3 times and whammy it hits . I then take the choke off and it starts right up.

I think what might be happening is the carb block has some pin holes in it and will not start till it gets enogh fuel in it to satureate the carb blkock.

Anybody else want to take a swing at it.

After it starts up the first time on the day of flying it will start right up the rest of the day.
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Old 04-27-2012, 05:51 PM
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RJ , When you are flipping it with the choke on, do you have the throttle open (off idle to half throttle) or closed (idle)?
If you have the throttle open it helps to draw more fuel into the crankcase .
If you are already doing this and still having problems 2 things come to mind .
1) you may have some reeds not closing completely and the backpressure blowing the fuel back out of the carb instead of drawing it in . (slight non sealing condition may not effect actual running)
2) you may have a minor vacuum leak leaning it out (least likely since you haven't described any other problems)

I would recommend trying some carb adjusting and maybe changing your start procedure first , then look into the 2 items above.
I had this concern on an older 3w70b2 and it ended up being the reeds and the rubber seal for the reed cage not sealing well.
I replaced the reeds and the seal and resolved the problem
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Old 04-28-2012, 03:14 AM
  #53
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CK1,

Yes I have the throttle open about half way when choke is on while flipping..

I will try replacing the reed valve, I think with whats going that would be the best solution. I will also replace the carb block just to rule it all out.

2 weeks ago I rebuilt the carb. I ordered the kit from a Big Blue store and it was pretty easy to rebuild. I thought that would have taken care of it but I guess I need to go alittle further into it.

That might even take care of gas running out of the carb while its running. after the carb rebuild it took care of some but not all of it. When it runs at an idle gas will drip out of the carb as well. Again not as bad as it did before the carb rebuild.
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Old 04-28-2012, 04:18 AM
  #54
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Default RE: Gas engine forum

RJ , on the gas dripping while running be sure the gasket on the needle valve side is against the carb body and not against the diaghram cover plate .the correct order is carb body-gasket-diaghram-cover .
If the diaghram is placed against the carb body it may keep the needle off the seat and cause the carb to drip fuel...
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Old 04-28-2012, 04:35 AM
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Quote:
ORIGINAL: CK1

RJ , on the gas dripping while running be sure the gasket on the needle valve side is against the carb body and not against the diaghram cover plate .the correct order is carb body-gasket-diaghram-cover .
If the diaghram is placed against the carb body it may keep the needle off the seat and cause the carb to drip fuel...
Yup done that. It was correct when I took it apart to change it all out. The leaking carb was the main reason I rebuilt it. It was also missing one of the cap screws that held the carb block to the reed valve block. That leaking air may have caused the reeds to go bad like what was said in a previous post so I will replace those next. I checked with AI and Cactus they both have them in stock. The good part is, it still runs strong once it gets started up LOL.
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Old 05-01-2012, 08:12 AM
  #56
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I just reciently purchased my first gas engine from Tower. It's an OS GT-33. I wanted to purchase some yellow tygon fuel line at the same time, but was unsure on what size to get. The OS GT-33 manual says to use a size of 3mm or greater ID. The only sizes I could find in Tower were 3/32", 1/8" and 5/32" ID. Would appreciate some information on the correct size to buy.
Thanks
Lamar
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Old 05-01-2012, 10:10 AM
  #57
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Default RE: Gas engine forum

Most people use the 1/8"
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Old 05-01-2012, 05:27 PM
  #58
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Thanks for the reply back w8ye. I was thinking 1/8" may be the best size, since 3/32" is a little smaller than 3mm and 1/8" is a little larger.

Lamar
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Old 05-02-2012, 03:36 AM
  #59
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Default RE: Gas engine forum

1/8 " is the way to go. I use it on my bigger gas engines as well. I also have found at Tower Hobbies a clear fuel line lines that come in a 50' roll at a very reasnable price. It also will grip the brass or copper lines with our barbs. I also use a zip tie or clamp on all fuel line connections.
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Old 05-02-2012, 06:37 AM
  #60
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RJ, this line from Tower hobbies, can you post a link? Is it flexible enough to use for the clunk line in the tank? Thanks, Duane
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Old 05-02-2012, 06:44 AM
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Default RE: Gas engine forum

this may be it from TH
LXYE85
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Old 05-02-2012, 11:10 AM
  #62
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I typed a fib, LOL. It is a K&S product and not Great Planes. Here's the link.

http://www3.towerhobbies.com/cgi-bin...?&I=LXYE85&P=0

Yes it is vary flexible! I took a tank apart that I had it in after a season of use and it was still just as flexible as the day it was installed. It looks and feels like the same stuff that they use on weedeaters or other 2stroke garden tools.
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Old 05-02-2012, 12:37 PM
  #63
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Thanks, RJ, for the link, got some on order today! }:<)
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Old 05-02-2012, 01:14 PM
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Hello fellow fuelers,
Newbe with gas here. Need some break in advice. I understand that normal break in is 5 tanks, and the first tank is at idle. What about the other 4 tanks? do you open the throttle more each tank? do you not want to open it up more on the 5th tank? Please give me a tank by tank rundown. Do you have to do all five tanks in one day? or can it be broken up over time? Just trying to do the right thing.


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Old 05-02-2012, 02:31 PM
  #65
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Default RE: Gas engine forum

I think you have a good idea.

Actually I start trying to get the needles set better after the first tank.

As soon as I think the engine runs good enough to put it into the air away it goes.

The first few flights, I fine tune the needles.

The engine is not really Broken in until you run a few gallons through it.
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Old 05-02-2012, 03:24 PM
  #66
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I agree with w8ye,

I try not exceed 4,000 RPM for the first tank and start the tuneing on the second. Once it's tuned and running a little on the rich side, up up and away! Remeber that in the air it will lean a tad bit so a little rich is good for break in. Also don't use synthetic oil for break in. I use penzoil for air cooled engines. Synthetics will luricate verry good but it will increase the break in period.

On the first flight don't hold the throttle wide open for to long and just keep it moveing through the air. The prop will draw alot of air over the engine but nothing compared to actualy flying in the sky.

After you feel the power increase by the torque and over all RPM of the engine your either there or real close. That's when I do the real fine tuneing for the way I like to fly. Just remember not to lean it before it's time, byleaning it prematurely it mayresault in a shorter life span of the engine.
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Old 05-02-2012, 04:23 PM
  #67
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Wow,
thanks guys for the great info. IM a ground guy. Driving my first nitro buggy.
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Old 05-02-2012, 06:29 PM
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Old 05-03-2012, 08:02 AM
  #69
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Quote:
ORIGINAL: RJStrickJR

I typed a fib, LOL. It is a K&S product and not Great Planes. Here's the link.

http://www3.towerhobbies.com/cgi-bin...?&I=LXYE85&P=0

Yes it is vary flexible! I took a tank apart that I had it in after a season of use and it was still just as flexible as the day it was installed. It looks and feels like the same stuff that they use on weedeaters or other 2stroke garden tools.
This stuff looks like the Tygothane I get from McMaster Carr. Tygothane costs 30c a foot plus s+h so it seems to be about the same price as TH sells it for....
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Old 01-20-2013, 06:04 AM
  #70
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I am brand new to this forum. Iam trying to find a USA dist for mvvs engines. I am interested mostly in the 58 cc rear carb for my 91" Extreme Flight Extra. Anyone help?
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Old 01-20-2013, 07:12 AM
  #71
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not going to happen here in the US,as close as your going to get is the Evolution58.same engine as the MVVS58,but they don't assemble the Evolution.
you could get a MVVS58 from Pe Reivers,at www.mvvs.nl
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Old 01-20-2013, 09:43 AM
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PM sent
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