Newbie question

[Fstnd378]

Hello, finally back with my FG monstertruck. It is finally making the sound how it's supposed to. Bogs down a small bit when I fullthrottle it in quart a second, but this was a small testrun as it had no airfilter on. But I realised, when giving throttle, there's exhaust fumes/blue smoke coming out of the intake side?

It must be wayy too rich as it almost suffocated me in blue smoke. Prob the reason for it to bog down

Is this normal and should I just put my filter back on, or... isn't it?

 

[Bizzer]

Please, for your own sake put the filter back on! That could be a costly mistake that will cost you an engine. Tune it with the filter on. Shouldn’t have that much smoke, but it’s hard to tell you what’s going on without hearing it. You have to get an ear for it.

 

[Fstnd378]

Please, for your own sake put the filter back on! That could be a costly mistake that will cost you an engine. Tune it with the filter on. Shouldn’t have that much smoke, but it’s hard to tell you what’s going on without hearing it. You have to get an ear for it.

Thanks! That filter is going to be attached from now on

Tomorrow or maybe today I'll test the engine again but with the filter. It'll have to be leaned out for sure

 

[Rep732]

It's not exhaust coming out of the carb. These engines are piston port style which a bit of the pressurized crank case air fuel mix is coming back out of the carb while the piston is on its way up. If it was a reed engine you wouldn't see anything come back out. This is perfectly normal and I agree please put your filter back on, if it runs with the filter on chances are your getting all the air the engine needs to breathe.

 

[Fstnd378]

Hey so I just started it up again, engine is hot enough, and it still bogs down? Lots of smoke but still bogs down? 2,5 full turns out on low, 2 turns out on high.

(Videl here soon)

Edit: maybe it's the fuel? It's been sitting in that tank for a month or two by now

 

[Ides28]

just don't forget you can damage the motor if you run it too lean. i would try not to go too much leaner than factory settings. i think you're right, that does sound rich. what are the factory settings for your carb? try 1/8 turn until it runs smoothly?

 

[Rep732]

Try leaning it out slowly on the low first, once you get it to stop bogging then tune the high end

 

[Fstnd378]

https://www.mediafire.com/file/qbfsdpuux2x1ja0/FGboggingdown.mp4/file

https://www.mediafire.com/file/n5f500lvub2qrq6/FGboggingdown_video.mp4/file

On the second link, you can see some of the car, on the first video there is only black, and for a few seconds I showed it idling. Edit: it's the other way around. I can actually touch the metal cooling plates around the cylinder infinetely long, but is this normal or shouldn't I be able to keep my fingers on it? It does hurt. If I'd unscrew the idle screw a bit more, the thingy thing wouldn't even be leaning on it...

Do you guys think it's a tuning issue or another airleak?

 

[Rep732]

Please make a YouTube channel and upload your videos for us to watch there. I won't nor do I recommend anyone else downloading files.

 

[Ides28]

i think tuning is more likely. gaskets ok? is the carb worn so the shaft wiggles in the carb? fuel lines ok? i wouldn't worry about heat unless you think you're overheating, go by if the car performs alright.

 

[Fstnd378]

i think tuning is more likely. gaskets ok? is the carb worn so the shaft wiggles in the carb? fuel lines ok? i wouldn't worry about heat unless you think you're overheating, go by if the car performs alright.

Gaskets are straight from factory I replaced all of them.

You're right,there is some minimal play between the carb shaft and the shaft that's attached to the red thing, with which you block the engine from air. Forgot the name lol. I have 2 carbs, but I think both have some play...

 

[Seandonato73]

The choke shaft won't make it run better or worse it's before the venturi. It will allow it to suck dirt through, but they arnt exactly super tight to begin with.

 

[Fstnd378]

Thanks for all the help. Today I replaced the fuelline where fuel flows to the carb, and ziptied it with hard pressure 2 times on both lines I think this could've solved the problem because the car runs fine now, no bogging down! Very easy fix actually. The car is still (very very)² smokey but that might be because of my awesome fuelmixing skills. I might've mixed it to 20:1

 

[Seandonato73]

It shouldnt really smoke at all with any decent oil and a good tune.

 

[Fstnd378]

It shouldnt really smoke at all with any decent oil and a good tune.

Today I went testing it, and had a small problem tuning it: going a bit leaner made the engine bog down, going a bit richer made the engine stall on idle while idle screw fully in. Engine kept stalling anyway tho. Motul 800 pretty high end stuff imo. I have a picture of the mixing can right before I mixed it:Recommend me making the fuel even leaner on oil? Because I found this after about 30min of driving:

 

[Seandonato73]

your idle screw shouldn't be turned all the way in! Red flag right there. Reset everything back to factory. Turn you idle screw in a few turns. Try to start it. You may have to turn it in a bit more, but it shouldn't be much. It should start and run with base carb settings. Tune from there.

 

[Fstnd378]

your idle screw shouldn't be turned all the way in! Red flag right there. Reset everything back to factory. Turn you idle screw in a few turns. Try to start it. You may have to turn it in a bit more, but it shouldn't be much. It should start and run with base carb settings. Tune from there.

Sorry I forgot to mention I tuned it multiple times to 1,25 turn on the LSN and about 1,5 turns out on the HSN. It did idle much higher, allowing me to screw the idle screw out a lot. But when applying throttle, the engine just bogs down...
It didn't get hot tho, which is why I'm wondering whether I should lean the fuel on oil
Thanks for all the replies!

 

[Fstnd378]

Tried leaning out the fuel yesterday to a bit less oil than 30:1, nothing changed except engine becoming hotter. But, could this all actually be caused by the bearings? The engine might be sucking air through them. Another reason I'm thinking about the bearings is because after a run, I can sometimes see some oil under the engine. This can't be caused by a defect gasket, as I replaced all of them, intake and exhaust

 

[misterleon]

Tried leaning out the fuel yesterday to a bit less oil than 30:1, nothing changed except engine becoming hotter. But, could this all actually be caused by the bearings? The engine might be sucking air through them. Another reason I'm thinking about the bearings is because after a run, I can sometimes see some oil under the engine. This can't be caused by a defect gasket, as I replaced all of them, intake and exhaust

The tune is off most likely your low and high is too rich. Obr made a great video a few years back on how to tune these engines so I recommend watching that before looking at other problems. I can almost guarantee with a strong grasp on tuning you could get it running right

 

[Fstnd378]

The problem is that the engine bogs down when at factory settings, and only (pretends) like it's okay when the tune is veryy rich. It does shut down when "idling". I remember I've watched probably the same
OBR vid some time ago, as well as some others
The problem is that the engine bogs down when at factory settings, and only (pretends) like it's okay when the tune is veryy rich. It does shut down when "idling". I remember I've watched probably the same
OBR vid some time ago, as well as some others