- Messages
- 3,624
- Location
- Queens
Then don’t say it was richeningBut, my engine starts up and runs fin for about 15 minutes and then goes super rich to the point where if you stop giving it throttle the engine will cut out.
Follow along with the video below to see how to install our site as a web app on your home screen.
Note: This feature may not be available in some browsers.
Then don’t say it was richeningBut, my engine starts up and runs fin for about 15 minutes and then goes super rich to the point where if you stop giving it throttle the engine will cut out.
My 36cc Rovan uses a composite carb spacer but other Rovan models might use alloy . I'm pretty sure that weak compression will allow an engine to run but will cause higher running temps from lack of power and not completely efficiently burning the fuel mixture .Sounds like heat soak to me. Had that happen due to a billet isolator for the carb. Your boiling the liquid gas which in turn leans the engine since there's less liquid fuel and your carb wasn't designed to meter a gaseous fuel only liquid so thats why it's hard to tune when the engine is hot....whats it like when you try to start it when the engine is hot.... how long does it take to start
I should be able to do a running video on sunday, but here are some pictures for now. The engine is stock, the fuel tank is venting, and if by isolator you mean the thing that goes between the carb and the engine, then yes it's plastic. I am running an NKG spark plug. I have run almost 30 tanks through this engine and there seems to be quite a lot of residue on the piston.Can you do us a favour please and post some pics of your rig? Doesn't have to be running, just that way we may be able to spot something that hasn't been explained.
Do you notice before it dies if the revs start raising or falling as you try to idle? What settings do you have your needles set at? Is your engine stock? Have you checked your fuel tank is venting properly? Have you checked your engine to make sure its not packed with grass beneath the covers? Do you have the stock isolator or have you upgraded to an aluminium one? What spark plug are you running? Have you checked head bolts are tight? Have you checked the carb/isolator gaskets are sealed?
Next time your out grab some video footage of what its doing, upload to Youtube and copy the link to the forum so we can view it to try and help further.
Ok thanks.Thanks for the pics.
So from what I can see you air filter is not stopping dust and dirt from entering your engine, could also do with cleaning, oiling and an outerwear looking at pics.
Your idle screw screw is wound all the way in.
The rig looks like its in desperate need of some cleaning and if you've ran 30 tanks through that engine without having to change the ring then my guess is thats about due, you've put about 6 gallons of fuel through it.
I pretty much concur with your assessment. Although by this point the op should notice a lack of power of its a ring issue.Thanks for the pics.
So from what I can see you air filter is not stopping dust and dirt from entering your engine, could also do with cleaning, oiling and an outerwear looking at pics.
Your idle screw screw is wound all the way in.
The rig looks like its in desperate need of some cleaning and if you've ran 30 tanks through that engine without having to change the ring then my guess is thats about due, you've put about 6 gallons of fuel through it.
Ok, thanks for the advice. Is there a way to check if there is an air leak?I pretty much concur with your assessment. Although by this point the op should notice a lack of power of its a ring issue.
Compression test will tell the tale of the ring.
The build up is from excessive oil, crap oil, and or excessively rich tune.
That old plug is less then worthless for checking tune. Needs done on new plug, with engine already to temp. Covered this many times already. Anyway. Stop looking at the plug it's worthless.
Either way your tuning is off as well. The idle screw sunk all the way or nearly all the way in means you have the low needle too rich, which could also mean your compensating for an air leak. I preach this all the time. Pressure and vacuum test to rule out leaks and bad seals. Compression test to check ring. I'd be surprised if all check out ok from the pictures you've provided.
The pic of the mud ingested carb venturi inlet tells me all I need to see. Sorry to be morbid, but your top end is junk, and your crank bearings are probably close to being junk. Your engine needs to come apart for an thorough inspection. Hopefully after dissasembly you can prove me wrong.I should be able to do a running video on sunday, but here are some pictures for now. The engine is stock, the fuel tank is venting, and if by isolator you mean the thing that goes between the carb and the engine, then yes it's plastic. I am running an NKG spark plug. I have run almost 30 tanks through this engine and there seems to be quite a lot of residue on the piston.
Ok I have some pictures of the inside of the engine, and the cylinder walls are quite scratched up and the piston has a few scratches and stains on it.Li
The pic of the mud ingested carb venturi inlet tells me all I need to see. Sorry to be morbid, but your top end is junk, and your crank bearings are probably close to being junk. Your engine needs to come apart for an thorough inspection. Hopefully after dissasembly you can prove me wrong.
After over 6 gallons of fuel I think he's due a rebuild anyways Junkie.Just tell Rovan that the filter (oiled properly) let dirt into the engine. He might give you a rebuild regardless of warranty
Register and gain access to Discussions, Reviews, Tech Tips, How to Articles, and much more - on the largest Large Scale RC community for RC enthusiasts that covers all aspects of the Large Scale RC!
Register Today It's free! This box will disappear once registered!
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.