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3.3 stalling while tuning

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Highway123

Highway123

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I just bought a used T-maxx with the 3.3. Took it out today and started tuning it. Set the LSN flush with the housing and set the HSN at 5 turns out. Made some passes and got the Maxx up to 205 degrees and started tuning. Started leaning out the LSN when half way through a test lap the Maxx stalled. I reversed my setting on the LSN and tried to restart but noticed excessive fuel on the breather element and inside the carb. It also sounded like it was flooded while trying to restart. Any ideas on what might be going on? I'm going to try again tomorrow with the tuning.

Thanks,
Highway
 
Start with the LSN flush. Pinch the fuel line and listen to the motor shutting down. A good setting will cause the engine to speed up just slightly when it runs out of fuel. Keep leaning the LSN until it does this. On the HSN, keep increasing the fuel until the engine performance starts to fall off and then go back to the setting just before it started to bog. I have two 3.3's and both HSN's are somewhere between 4.25 and 4.75 turns open. BUT, to add to this, I had a 3.3 that was blowing fuel back up through the carb and it turned out that the pinch was gone and I replaced the sleeve and piston. Take your glow plug out and rotate the engine. When the piston reaches top dead center (TDS) you should be able to feel a little bit of resistance. If you don't feel it tighten up a little, your pinch on the cylinder is probably gone.
 
Highway123 said:
I just bought a used T-maxx with the 3.3. Took it out today and started tuning it. Set the LSN flush with the housing and set the HSN at 5 turns out. Made some passes and got the Maxx up to 205 degrees and started tuning. Started leaning out the LSN when half way through a test lap the Maxx stalled. I reversed my setting on the LSN and tried to restart but noticed excessive fuel on the breather element and inside the carb. It also sounded like it was flooded while trying to restart. Any ideas on what might be going on? I'm going to try again tomorrow with the tuning.

Thanks,
Highway
Click to expand...

You didn't say whether it ran fine or not before you bought it. Since you're trying to reset and retune it it sounds like probably not. Depending on its hx and how much of it you know about, it's probably time for a new or rebuilt 3.3.
 
Nitro_Ninja said:
You didn't say whether it ran fine or not before you bought it. Since you're trying to reset and retune it it sounds like probably not. Depending on its hx and how much of it you know about, it's probably time for a new or rebuilt 3.3.
Click to expand...

It was running good. I ran it for 15-20 minutes the day I bought it and then yesterday for about 10 minutes until it warmed up and I started tuning.
 
Is the HSN still out 5 turns? Try leaning it out some until it will start. Mine won't run at all past 4.5 turns. Factory setting is 4 turns out.
 
If your getting raw fuel out of the pipe your flooding the eng. Go back to the stock setting making sure your idle gap is 1mm open with the brakes applied and tune from that point, also make sure your glow plug is good even if it looks good it can be bad test before you install it. One mistake a lot of people do is set the lsn to rich and they try to lean it with the hsn, this is not a correct way to tune the eng, make sure you start with factory setting and don't touch the idle screw and only adjust the lsn after your hsn is adjusted correctly and the eng is at operating temp. After you adjust your lsn you may have to slightly adjust your idle and possibly tweak your hsn.
https://www.rcnitrotalk.com/forum/showthread.php?t=60832
This is a good chart to follow.
 
nikko508 said:
If your getting raw fuel out of the pipe your flooding the eng. Go back to the stock setting making sure your idle gap is 1mm open with the brakes applied and tune from that point, also make sure your glow plug is good even if it looks good it can be bad test before you install it. One mistake a lot of people do is set the lsn to rich and they try to lean it with the hsn, this is not a correct way to tune the eng, make sure you start with factory setting and don't touch the idle screw and only adjust the lsn after your hsn is adjusted correctly and the eng is at operating temp. After you adjust your lsn you may have to slightly adjust your idle and possibly tweak your hsn.
https://www.rcnitrotalk.com/forum/showthread.php?t=60832
This is a good chart to follow.
Click to expand...

Well today I actually did that, brought everything back to factory settings and it started up. It was bogging out for a bit and then started clearing up. It kept shutting off if I came off the fuel a bit. It was starting to warm up when it shut off again, I tired to restart it with my EZ start and nothing. The EZ start will just click, I can see the EZ start motor moving but it acts as if the motor locked up.
 
I've never seen a running engine so rich that it hydro locks (fills with fuel)


My tuning proceedure is as follows:-

Depending on temp and climatic conditions, generally I will start a little over flush on the low speed (1 ¾ turn out from base) and the HS 4 turns with a stock pipe and 4.5 turns with a tuned pipe . . .

Start – warm her at idle for a bit, ease on the throttle – if she stalls, then I bring in the LS 1/8th – start again – when I can ease the throttle on without stalling I will do a little warm up until she is to temp.

So long as I can accelerate from an idle without stalling I wont lean out the LS at this stage.


Do some WOT runs – if she feels soft in the upper RPM I start leaning down 1/8th turn on the HS until it sings at WOT – throughout this process, I’ll check to ensure my temps are ok and I haven’t gone too far.


Once the HS is set (I normally leave a bit of fat in her) I’ll lean the LS 1/8th turn at a time until acceleration is crisp and swift (she pops the front wheels effortlessly each time I hit the throttle)


Generally, I tune with a full tank and leave a little fat in the tune, as the fuel level goes down, power generally goes up. I figure I would rather be a bit rich on the HS with a full tank and lean down to a perfect tune, than to be spot on with a full tank, and lean as the fuel level in the tank drops.


- How new is this engine of yours?

- I would be surprised if it is hydro locked - perhaps remove the plug and try the starter - clear out the fuel (if she is rich) and ensure it's not seizing (because she is hot and lean)


Are you making very small adjustements to the HS jet? As in 1/8th of a turn?

If you are wrenching the tune 1/4 at a time you can miss the ideal window completely - small adjustements.

I found with a stock pipe I'm pig rich at 4 turns out and I am around 3 3/4 turns on the HS when tuned . . . with a aftermarket 'tuned pipe' I start at 4.5 turns out and am only a couple of 1/8th turns out on the tune depending on the conditions.
 
It may very well be locked up. Need to pull ez start off remove back plate and check block for metal shavings or a broken rod. Also remove cooling head and inspect top of piston for pitting or dark discoloration. The 3.3 is notorious for snapping the rods when ran too lean. In all it sounds like you need to replace it. Rebuilding the 3.3 is pointless when just for $20 more you can buy a new one. Ebay is your friend in this matter.
 
Pull the glow plug, flip the truck upside down and spin the ez start a couple times, it sounds flooded.
 
Do whats recommended above my last post before you go tearing into the engine. He was typing faster than me i guess. But if its not turning over at all after you remove plug and check for hydrolock. Then worry about a broken piston and rod.
 
Zdragon71 said:
Do whats recommended above my last post before you go tearing into the engine. He was typing faster than me i guess. But if its not turning over at all after you remove plug and check for hydrolock. Then worry about a broken piston and rod.
Click to expand...

Just pulled the head, I was hoping for hydrolock, all the symptoms pointed to that but it seems the motor is gone, there's metal all over the piston and when I tried turning it over using a screwdriver against the flywheel it's locked tight.

So my next question is; do I rebuild or do I go with a picco Red Dot .26:D?
http://www.amainhobbies.com/product_info.php/cPath/1_23_2156_1936/products_id/25772/n/OFNA-Picco-26-MAX-JL-Red-Dot-Nitro-Engine-w-Pull-Start
What do you guys think?
 
The picco shortage is still an issue. If you can find one i would jump all over it. Buy a new anything will be more cost efficient than rebuilding.
 
UPDATE:

Pulled the engine out and broke it down. The skirting on the piston is broken. The rod bearing had a lot of play and there's scarring on the block wall from the rod scraping the block.
 
Sure it isnt just scaring on the piston sleeve. The brass sleeve comes up out of block to be replaced with new piston. The sleeve is what has the compression pinch at tdc.
 
Zdragon71 said:
Sure it isnt just scaring on the piston sleeve. The brass sleeve comes up out of block to be replaced with new piston. The sleeve is what has the compression pinch at tdc.
Click to expand...

The bottom of the rod at the rod journal was hitting both bottom sides of the block.
 
Here's the Maxx with the Picco installed. I'm at 8 tanks so far on the break in process. The body is a 67' Ford F100, the same truck I drive everyday. I thought it was cool.:D
 

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