Seven Month Old Engine wont start.

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, and others.
cardarear

cardarear

Well-Known Member
Messages
66
Location
Oakland County, MI
I'm beginning to understand why there are those who prefer electric RCs. With my electrics I head out to a spot fully expecting to run my RCs for a bit. And for the vast majority of the time that's exactly what happens. Now with my Vekta.5 it's more like "let's just go out and see if it starts", because on any given outing it's just as likely to not start as to start. That was until the last two weekends when I have not be able to start it at all. Maybe someone here can provide some advice as to what I'm doing wrong.

My setup is a Vekta.5 with an OBR G340 full mod engine, 990 carburetor, and dominator pipe. The engine is about 7 months old with just over a gallon of fuel through it. To start it I generally add fuel, checking to make sure the hole in the fuel cap is not blocked. Then I press the primer bulb until it's filled and make sure there is fuel going through the return line to the tank. I pull the pull cord slowly about 3 times. Then I power up the transmitter and check to make sure the Super Bee kill switch is deactivated on the transmitter. Next power up the Vekta and listen for the Super Bee which will chime a few times and then go silent if all is well. Now I start to pull the pullstart to fire up the engine. If I have not messed with for a day or so it May Fire up for a few seconds before cutting off (even if I'm giving it throttle on the transmitter). Once it cuts off I can not restart at all.

I tried resetting the carbon needles to default settings (1 1/8 low and 1 5/8 high). I also tired adjusting the low needle 1/8 leaner then 1/8 richer. I bumped up the idle screw to almost maximum. I replaced the spark plug and added fresh fuel (93 octane mixed 28:1 with Castor 927) and retried everything above. I tried loosening the gas cap. I inserted a spark tester between the coil wire and the plug and verified there was spark. I thought maybe I flooded it. I turned it upside down with the spark plug removed and pulled the pull start a handful of times, then re-added the plug and tried to start it. I removed the carbon completely and tried to start it. I added a squirt of sure start into the engine with carburetor removed and tried to start it. So far nothing has worked. I haven't checked compression but I don't really know how yet.

If anyone has any ideas I would greatly appreciate it.
 
Has you plug been wet after you've tried to start it? Have you had the carb apart and checked it out to see any dirt? If it pulls over with a decent amount of resistance chances are it's not a compression issue. And have you checked the Reed block for damaged missing or stuck open petals?
Also OBR has some nice vids on their sight that are worth checking out.
 
Seandonato73 said:
Has you plug been wet after you've tried to start it? Have you had the carb apart and checked it out to see any dirt? If it pulls over with a decent amount of resistance chances are it's not a compression issue. And have you checked the Reed block for damaged missing or stuck open petals?
Also OBR has some nice vids on their sight that are worth checking out.
Click to expand...
The spark plug is wet when removed. I have not tried to clean the carb, I thought I was eliminating that as a root cause by removing it and trying to start the engine with sure start. I can try that tomorrow, nothing to loose. I have the non reed case engine.
 
Also ,if there was any kick back or miss fire ,you can check the flywheel's woodruff key ,sometimes they will
sheer an throw the spark timing off ,but ,you can check the small stuff first ,like checking an make sure
the head bolts are tight!
An check what others had mentioned ,sometimes it could be something simple like a leaky carb gasket!
 
Check for leaks. Are you still running a plastic manifold behinde the carb? They have been known to crack occasionally. It should have at least sputtered on either with out the carb. Another thought. You said you used an inline spark tester? Take the plug out and make sure its sparking. Even a half arse shot plug will make an inline tester light up
 
Z.hb71 said:
Also check if maybe the pulse hole is blocked on the carb, carb gasket, intake manifold, ect, that could be ur problem. Or it could be bad diaphragms but I son't think it's that
Click to expand...
I removed the carb and checked the pulse holes between the engine the gaskets and the black spacer. Everything appears to line up and there is no blockage. I reassembled it, confirmed the needles were in the stock settings and tried to start it again. No luck.
 
cardarear said:
I removed the carb and checked the pulse holes between the engine the gaskets and the black spacer. Everything appears to line up and there is no blockage. I reassembled it, confirmed the needles were in the stock settings and tried to start it again. No luck.
Click to expand...
Could be a problem with the Reeds, are they blocked somehow? Are they not opening? Check it out
 
cbaker65 said:
There is no oily fuel residue around the head or where the engine case splits apart? Sometimes
if there is a leak in those areas ,the engine will not run!
Click to expand...
I looked and ran my finger around the top of the crankcase /bottom of the head and did not notice anything abnormal.
Seandonato73 said:
Well if all else fails give the boys at OBR a call or email. One of their engines just doesn't crap out after 7 months.
Click to expand...
I did send them a message, I'm trying recheck everything I can while waiting for a response. Thanks
 
Seandonato73 said:
Check for leaks. Are you still running a plastic manifold behinde the carb? They have been known to crack occasionally. It should have at least sputtered on either with out the carb. Another thought. You said you used an inline spark tester? Take the plug out and make sure its sparking. Even a half arse shot plug will make an inline tester light up
Click to expand...
I am running the plastic manifold. I did take a look at it when checking the pulse holes. I did not notice anything wrong with it. I took another look at the spark plug. I'm getting a dim yellow spark. I had to turn all the garage lights off at night to see the spark. I checked the gap and it matches the Zenoah specification for the G320rc engine. I'm going to get a new plug and see how that goes.
Z.hb71 said:
Post up their response
Click to expand...
Will do
 
cbaker65 said:
There is no oily fuel residue around the head or where the engine case splits apart? Sometimes
if there is a leak in those areas ,the engine will not run!
Click to expand...
This has happened to me ? your compression will suck if you have a problem
Seandonato73 said:
Well if all else fails give the boys at OBR a call or email. One of their engines just doesn't crap out after 7 months.
Click to expand...
My motor was from OBR I mailed Sean he was awsome ??
cardarear said:
I am running the plastic manifold. I did take a look at it when checking the pulse holes. I did not notice anything wrong with it. I took another look at the spark plug. I'm getting a dim yellow spark. I had to turn all the garage lights off at night to see the spark. I checked the gap and it matches the Zenoah specification for the G320rc engine. I'm going to get a new plug and see how that goes.

Will do
Click to expand...
Put a new plug?? and if it was me I'd put an 1107 carb??
 
Definitely change the plug. If you're only getting a dim yellow spark, you aren't getting enough 'splosion. It should be blue/white. If the new plug is having the same issue, check your ignition coil gap on the motor. It might have shifted with vibration and is gapped too wide. Use a standard business card between the ignition coil and flywheel magnet and reposition it. If the spark is still weak, check the plug wire for any faults. If you can't find any issues there, you might need a new ignition coil. Luckily, they're pretty cheap.

Best of luck!
 
AnubisBC said:
Definitely change the plug. If you're only getting a dim yellow spark, you aren't getting enough 'splosion. It should be blue/white. If the new plug is having the same issue, check your ignition coil gap on the motor. It might have shifted with vibration and is gapped too wide. Use a standard business card between the ignition coil and flywheel magnet and reposition it. If the spark is still weak, check the plug wire for any faults. If you can't find any issues there, you might need a new ignition coil. Luckily, they're pretty cheap.

Best of luck!
Click to expand...

Agree on spark plug ,as I had some that the gap completely closed up before!
 
Dan from OBR called. He suggested disconnecting the quick connect to the killer bee switch before looking at the ignition coil. If the spark improves then I have a bad kill switch. I did have a melt down in my battery box about a month or so ago. The truck was down for several weeks while I replaced electronics and re-did the wiring. I didnt see any physical damage to the kill switch and it seemed to be functional but there could be something going on there. I will check this out first thing when I get home today.
 
cardarear said:
Dan from OBR called. He suggested disconnecting the quick connect to the killer bee switch before looking at the ignition coil. If the spark improves then I have a bad kill switch. I did have a melt down in my battery box about a month or so ago. The truck was down for several weeks while I replaced electronics and re-did the wiring. I didnt see any physical damage to the kill switch and it seemed to be functional but there could be something going on there. I will check this out first thing when I get home today.
Click to expand...

Keep us posted on the results?
 
Dan appears to have been correct about the kill switch. The spark is now brighter and white/blue in color. Unfortunately I was still unable to get the engine started. This was with the existing spark plug. I still have new spark plugs on the way.
 
Back
Top
✖
AdBlock Detected

We get it, advertisements are annoying!

Sure, ad-blocking software does a great job at blocking ads, but it also blocks useful features of our website. For the best site experience please disable your AdBlocker.

I've Disabled AdBlock    No Thanks