Engine replacement for .15 associated truggy

[D3MON]

i would see if you might be able to adjust the o-ring or get a new silicone o-ring first, tanks for those are not cheap because of their age and people buying them up. last i saw was around 55$ on ebay, though you may have better luck finding one than i.

or pressure testing the tank. plug one line, dip the tank into a tub of water and blow into the other line and see if you get air bubbles.
make sure to completely rid the tank of water and be completely dried before trying to use the tank again to run the vehicle. last thing you want is water in the fuel.

 

[Billys rc]

would any silicone o ring work if the right size and is their suppose to be an o ring on the carb where it goes into the block?

 

[Billys rc]

 

[Billys rc]

Tank doesn’t leak.

 

[D3MON]

would any silicone o ring work if the right size and is their suppose to be an o ring on the carb where it goes into the block?

there should be a thin seal between the carb and tank.
it does look like you are leaking some fuel somwhere out of the carb, or at the carb connection, or is that my eyes playing tricks on me?
as long as its a silicone o-ring nitrile will be degraded by the methanol of the fuel.

 

[Billys rc]

I’m not sure we’re an o ring would go cause there want one on the carb that slides into the engine. The fuel is leaking and dripping in a gear and it slings it up

 

[Billys rc]

 

[D3MON]

this is where the o-ring would be.
you can have fuel leak from there, from the idle needle, or the LSN, it can also leak from the front bearing if it was too rich and you were trying to start it.
typicalyl when running the fuel/oil mixture will create a film around the tip of the crankshaft in the nosecone. so it wont leak, but when its too rich the excess fuel pushes out the bearing. the bearings have "seals" but they dont actually seal, more of a shield. to prevent dirt getting it.
given it was spraying fuel and oil out the exhaust, i am going to guess it was jsut super rich and over primed. when priming, blow fuel in until the fuel gets to the carb, then one extra little bit of pressure to force fuel into the crankcase. just a little though.

 

[Billys rc]

I made a makeshift o ring and the leak stopped but what is LSN and I’m gonna try and get it fired up in the morning

 

[D3MON]

I made a makeshift o ring and the leak stopped but what is LSN and I’m gonna try and get it fired up in the morning

LSN is the "Low Speed Needle", it affects the fuel mixture for 0-25% throttle range.
HSN is the "High Speed Needle" it affects the fuel mixture for 25-100% throttle range
i would look up a few tuning guides to be able to get familiar with tuning these.
its best to always start at factory settings, which can be found in the manual for the engine
https://img2.associatedelectrics.com/pdf/discontinued_items/12.15.18_manual.pdf
once you get set to factory, follow step #4 in the manual.
keep in mind it is always safer to tune to be on the slightly rich side. typically people will get to almost peak power after leaning it, then richening up the mixture by about 1/12-1/8 of a turn to be on the safe side.
make sure that there is always a trail of smoke, and always adjust one needle at a time while tuning it in and by very small increments (1/8-1/12 of a turn)
turns are full 360 degree rotations of the needle, judged by the flat blade where the screwdriver turns the needle.

 

[monstertruckier15]

So I have an older associated truggy is is spitting fuel and has not fuel pressure if needle is open at all I’m pretty sure engine seals are toast I was wondering what would be a good replacement engine I kinda wanna do a fast build and now I have a reason. Any help would be great.

This where you should have started. .12-.15-.18 Engine Manual (associatedelectrics.com) Now that the engine was disassembled you should have checked the condition of the piston/sleeve by sliding the piston threw the sleeve manual and see how far from the top it stops. Past is bad. Clean it inside and out and use fuel with 18% oil lube and castor oil.

 

[D3MON]

going have to agree to disagree with the oil percentage but that is a good way to test for compression.

 

[monstertruckier15]

The engine is toast! I have the same engines and truck and I only run 18% oil lube in everything. Who ever had the truck before used car fuel and these old engines don't like it for long. A new engine will cost $100 or more.

 

[D3MON]

The engine is toast! I have the same engines and truck and I only run 18% oil lube in everything. Who ever had the truck before used car fuel and these old engines don't like it for long. A new engine will cost $100 or more.

huh?
is a video not loading or something or how do you know the fuel used and the compression of the engine without seeing anything internal on the OPs engine including the way to test its compression?
sorry but that's just silly and reckless to tell someone their engine is toast and to go spend a bunch of money without actually knowing.
ae .15s last just fine on this evil "car" fuel... you do realize that both air and car fuels both typically have castor oil in them right? (few instances where it is full synthetic, but typically for off road basher fuel only because they dont stay at or near WOT all the time.
castor leaves a lot more residue behind because it doesn't burn until 480F plus degrees.
oil also doesn't compress, so too much oil is harder on the piston and rod unless there is lack of compression which will allow the oil to blow by the piston in the sleeve.

 

[monstertruckier15]

Just by looking at the inside of the engine it is toast. A good engine shouldn't look like that. I've seen worse black. Dark brown is just as bad. There shouldn't be any discoloration inside. A sign that the engine was run too lean with not enough oil lube.

 

[D3MON]

Just by looking at the inside of the engine it is toast. A good engine shouldn't look like that. I've seen worse black. Dark brown is just as bad. There shouldn't be any discoloration inside. A sign that the engine was run too lean with not enough oil lube.

lol there hasn't been a single picture yet of where you can see a picture of the internals of OPs engine, and in the pictures of cbakers engine still can't see how much compression the engine has to be able to call the engine toast.

 

[cbaker65]

I kept going back to look ,LOL...for pics!...?

However ,a few things that I may point out ,is the location of the pressure tube that goes
into the pipe ,seems to be more on the bottom side ,I would twist the upward to where it
is on top ,pull the line out an cut tip of it in an angle to were the line is not plugging its
self off ,also ,I would replace the header pipe gasket an put new zip ties on the pipe coupler
to insure that it has a tight seal!
All in all ,I wouldnt tear the engine completely down ,I would just get those parts sealed ,an
seal the carb.,pull the needles an rub the O-rings down with some sticky grease ,an see if it
will run!...?