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Car keeps shutting off

10K views 34 replies 16 participants last post by  Rodadon 
#1 ·
hey guys, recently i took my baja out for a spin, to realise it was hard to start.

after i got it to start, i went good for like 5 minutes, then it turned itself of and then proceeded not to start anymore.

(Both TX and RX batteries are good, failsafe off too)

thoughts?
 
#2 ·
Check for spark.

One of the guys here had the same type of problem - he said it was a dodgy spark plug clamp.
 
#4 ·
Usually when that happens, it means you have a leak somewhere. Replace all the seals from the carby.

The motors dont like high octane fuel either. Just use normal 95 from your local and replace the plug as well.

With that much carbon on top of the piston, a chunk might have fallen off and scored the piston as well. Another one is that hole looks dry. When its dry, its running really lean! Might have lost compression thats why it keeps cutting out.
 
#5 ·
Check the coil for correct gapping (.30 mm)
Check plug
Check carb gaskets, and needle settings
 
#7 ·
I'm also using 98, with Silkolene Pro KR2 Go-Kart Oil. The manual says to use 92-98 (91 & 98 were the only fuels available at my local service station).
 
#9 ·
you can use hi octane if you want, but it will have no effect on the performance, generally a 95RON fuel is the best.

As for the carbon build up on the piston, check your seals, specifically on the exhaust, i suspect you have excess oxygen in the cylinder
 
#10 ·
When i raced, i used a higher octane (higher than 98) and it spat and coughed. Used 98, had minor tuning issue then 95 not a problem at all. Just based on my experience, just sharing what i thought.

Ran a 2 bolt 23 then a ported 23 then a stock 4 bolt 26 and stock 29.

First up, replace the spark plug and see if it runs. Then replace the seals, run it. Then replace the seal on the exhaust. If all fails, you might have some ridges on the piston and head. Only way to know is if theres lack of compression and opening up the motor for a look see.
 
#11 ·
Check the basics to start with.
Spark, fuel & air.

I've had 2-strokes that don't run well due to wear and tear, but they've run.
 
#13 ·
I was running kr2 oil for almost 2 years and it will do that, just change yiur plug and it should fire up

As for the carbon ontop of the piston, I wouldnt worry about it....when I pulled my engine down after about 30 liters I had a THICK layer of carbon on there like it was painted on and not a single chip in it...it holds tofether very well

I ran 25 to 1 oil mix with premium too

Sent from my GT-I9300T using Tapatalk 2
 
#17 ·
Listen to L_D the large scale expert :p
 
#16 ·
I had issues with my car cutting out and it seemed no matter how I tuned it, it would still cut out now and then.

I have just replaced the carby with a new one that has ball bearings on the throttle shaft from PSR. The throttle shaft has play in it and might have been a bit worn out.

I have yet to run it, but at just over $60, it wasn't much really.

Cheers Dave.
 
#19 ·
Take a pic of ya PLUG end, the bit that goes in the engine.

Carbys on these have a the fuel pump in them. If you get an air leak in them or the inlet gaskets you get a fuel starvation.

Don't worry about carbon every 1:1 engine I have every pulled down has carbon build up, its part of burning a hydrocarbon. The last bit of that word is carbon and that is what seperates during combustion. The only clean piston I have ever pulled out of a engine, was with a coolant leak into that cylinder, as the water burns the carbon off and removes the molecules in the steam.
 
#22 ·
Had a similar issue recently, hard to start, once it did start it would randomly cut out after a while. Went through and checked the piston and found scoring on it and the head cylinder. Must have dusted at some point so it was losing compression. It might be worth checking if you have gone through everything else. They aren't hard to replace and not that expensive either.
 
#23 · (Edited)
How hard or easy does the pull start come out, if it comes out with little or no resistance it maybe down on comp.

Also have you cleaned out all the crap under the black engine cover, the poor thing might just be overheating. I had one of those mesh covers on my pull start and my engine would overheat and keep stalling, pulled it off and it was fine again. Not knocking these covers, I think there a great idea I just had issues with mine restricting air flow.

Other things I have had it the cage knocking the choke lever down just enough that it would stall.
 
#25 ·
if your car ides ok then your carby should be ok, unless its a ruxing one toss that and get a walbro..if it had a air leak it would stall at ldle , unless you compensate it by giving it more fuel ..still you would know as the Low speed needle on 99% of the cars are about 1and 1/4 wound out.. around that mark..

if your car is running and stalling after 5 minutes then i would check the breathe hole in your fuel cap..probably blocked , or the carby insulator block is warped and when it gets hot it expands and lets in air or vaporates the fuel.. seen that quite a few times..

try running with the cap loose enough not to fall of and air being able to get in ..if that doesn't help it change your carby insulator block..
 
#26 ·
hmm okay so, i just pulled apart the whole thing (fuel tank out etc) and took of the carby, it seems to be quiet clean? like it always gets dirty around the carby needles, but when i took the carby off, the inside looks clean? and it did idle okay, but now i need new gasket :(
 
#28 ·
Holy hell that thing is shiny as they come, I take it, its not too old. Might want to start playing, wind the needles out, better rich than lean, start with the high, see if its better or worse. If better leave it or a little more out, if worse wind in a little past ya start point.

What's ya oil ratio, maybe you just had too much oil?
 
#29 ·
yeah don't worry to much about the inside its fuel so they will always bee clean..

your prob i guess is the thing shutting of after 5 mintues of run time, while ya got it like that and going to get gaskets you might as well change the insulator block..

by the way what brand is stamped on that carby..looks to be a walbro..

is that a crack on the coil i see, also clean around the terminals of the coil if water and grass gets on it it will arc out and cut the engine..
 
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