Rovan 1/5 5b

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skaterriese45

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Messages
8
Hi everyone, I'm new to the 2 stroke rc's but absolutely love it so far. I bought a rovan baja 30.5cc. I was curious why it takes so long to start. I have to pull the cord forever to get it started and usually floods multiple times. I have completed the break in process and have had it professionally tuned. But when I go to start it the next day, it takes so long to start. Already went through 2 pull cords. It has a new ngk plug in it and 93 octane fuel with 25:1 VP 2 stroke oil. Thanks for any help!
 
are you trying to get it started with the choke on mate?
starting procedure that a lot of us use is,
1, pump carb bulb till fuel starts to flow through return line,
2, choke on and pull slowly till you here a pop, usually a couple of pulls ,
3, choke off and pull, should start within 3 to 5 pulls,
short sharp pulls and don't pull the starter cord all the way out, what i mean is don't yank the feck outa the starter or yer gonna snap the cord or break sommat on the starter,
try the above and see if it gets ya sorted (y)
 
spents said:
are you trying to get it started with the choke on mate?
starting procedure that a lot of us use is,
1, pump carb bulb till fuel starts to flow through return line,
2, choke on and pull slowly till you here a pop, usually a couple of pulls ,
3, choke off and pull, should start within 3 to 5 pulls,
short sharp pulls and don't pull the starter cord all the way out, what i mean is don't yank the feck outa the starter or yer gonna snap the cord or break sommat on the starter,
try the above and see if it gets ya sorted (y)
Click to expand...
Thanks for the reply! I never get that "pop" like in all the videos I watch. I always prime the bulb first until the bubbles are out of the yellow fuel line, then turn choke on and pull but it never pops :/
 
when you say you had it professionally tuned after break in,
what did it start like before it was professionally tuned?
and was the professional that tuned it really a professional?
 
Three things could be in play.
1. Check for spark as you said you replaced the spark plug. You will have to remove the plug, connect the ignition wire and touch the threaded part against the engine. Pull the cord and see if you get spark. If not, it could be the stop switch is stuck in shorting position or if you have a remote kill switch it may be shorting out the ignition coil. It may be a bad plug, damaged coil spring in the ignition wire that secures it onto the plug, or the air gap has changed on the ignition coil if the screws vibrated loose when the engine was run the last time. If you have spark, you do not need to check the air gap.

2. Air gap on the ignition coil has changed. If the screws were not tight, the ignition coil could have moved due to engine vibrations. You will have to remove the fan cover to adjust the ignition coil. With a Rovan, will have 4 screws that secure the fan cover to the chassis. The two bottom screws, and one on each side midway. Then you can remove the three screws that hold the fan cover in place as well as the two Phillips head screws that secure the cowl. It can be a pain to remove all the screws if there was any thread lock used when it was assembled. Do this as a last resort if the engine cannot be started and only if there is no spark.

I had an air gap issue on the ignition coil with my KM30.5 right out of the box. Engine only started once and that was it. Did not think to check the air gap but that fixed the issue once I did check it. Typical index card or business card would be about the right thickness if you do not have a flexible feeler gauge to set the gap.

3. Tune is not correct for the engine. Return to recommended stock settings. Also, if the idle speed control screw is too far out, the throttle plate will be closed all the way. I would readjust the H/L needle settings first before making adjustment to the idle speed screw (it is the one that adjusts the throttle lever just below the H/L screws.

If the carb was removed or if not installed properly, it could also be a gasket issue not sealing the pressure port to jet the fuel. If the hole on the bottom of the intake manifold is blocked or if the manifold has a crack in it, this will cause issues. There is also a top hole but that does nothing. It is just there so the intake manifold can be installed in either direction.
 
spents said:
when you say you had it professionally tuned after break in,
what did it start like before it was professionally tuned?
and was the professional that tuned it really a professional?
Click to expand...
Same exact starting issues as I'm having now.
Phill2 said:
Walbro is the go.
You'll want a WT668 for a 30.5cc.
Click to expand...
I will certainly look into this as an upgrade!
Bandit2013 said:
Three things could be in play.
1. Check for spark as you said you replaced the spark plug. You will have to remove the plug, connect the ignition wire and touch the threaded part against the engine. Pull the cord and see if you get spark. If not, it could be the stop switch is stuck in shorting position or if you have a remote kill switch it may be shorting out the ignition coil. It may be a bad plug, damaged coil spring in the ignition wire that secures it onto the plug, or the air gap has changed on the ignition coil if the screws vibrated loose when the engine was run the last time. If you have spark, you do not need to check the air gap.

2. Air gap on the ignition coil has changed. If the screws were not tight, the ignition coil could have moved due to engine vibrations. You will have to remove the fan cover to adjust the ignition coil. With a Rovan, will have 4 screws that secure the fan cover to the chassis. The two bottom screws, and one on each side midway. Then you can remove the three screws that hold the fan cover in place as well as the two Phillips head screws that secure the cowl. It can be a pain to remove all the screws if there was any thread lock used when it was assembled. Do this as a last resort if the engine cannot be started and only if there is no spark.

I had an air gap issue on the ignition coil with my KM30.5 right out of the box. Engine only started once and that was it. Did not think to check the air gap but that fixed the issue once I did check it. Typical index card or business card would be about the right thickness if you do not have a flexible feeler gauge to set the gap.

3. Tune is not correct for the engine. Return to recommended stock settings. Also, if the idle speed control screw is too far out, the throttle plate will be closed all the way. I would readjust the H/L needle settings first before making adjustment to the idle speed screw (it is the one that adjusts the throttle lever just below the H/L screws.

If the carb was removed or if not installed properly, it could also be a gasket issue not sealing the pressure port to jet the fuel. If the hole on the bottom of the intake manifold is blocked or if the manifold has a crack in it, this will cause issues. There is also a top hole but that does nothing. It is just there so the intake manifold can be installed in either direction.
Click to expand...
Thank you for all this info! I definitely did the spark test with the new plug and had plenty of spark.

The tune was the factory settings for break in, then went by sound/feel after that.
 
Testing the spark plug in open air doesn't tell you much. Under compression it may be weak. Covered this a few times. Get a cheap ignition tester. Set the screw to small engine. It simulates the compression in an engine and loads the system. I doubt this is your issue tbh.
Rovan does use genuine walbro carbs for the most part. They are made by walbro for rovan. Covered this a few times as well.
Coil gap can be set with a business card.
Plugs are typically gapped close enough from the factory for these engines.
The insulator blocks are know issues, but that would lead to a lean run condition, as well as any sort of bad asset issues.
I'm on the piss pore tune boat. Return to factory settings and go from there. Half the "fun" of a 2 stroke is learning how to tune it.
The search function on this forum is a powerful feature. I've previously covered in depth the proper way to read a plug, including a plug chop.
 
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