Oh How Original Posted November 17, 2013 Author Share Posted November 17, 2013 the idle screw limits how far back the butterfly can go, so screwing it in is only going to make it idle faster, the throttle trim can not counter it. at the very least make sure the idle screw is touching the metal plate thingy (i don't know its name either) if it is vibrations causing it then the servo can atleast push it against something to limit it. failing that see if putting the idle screw in a small way and raising the idle speed stops it, i know if mine are set too low they don't idle evenly due to not enough air/fuel flow so maybe that will stop it. as for the spring it usaly best to replace them once they loose their strength but you can pull them open slightly and it will give them alittle more life, however while you can do this afew times you can stretch it too far and it won't do a thing. there is also the possibility that you just need to clean it up or rebuild it, the outside my be clean but the last owner may have never opened it up to clean it out. Good couple of things to try there, cheers Paul. Quick question, can you actually get rebuild kits for carbs? I was just presuming I could I figure as I'm going to stick with the 668 if I have to buy a new one, I may as well try rebuilding it if the kits exist and aren't too expensive. I'm pretty sure this is a 668, but I'll know for certain when I take it off. If it doesn't have any markings at all and it's just a cheap copy one, it might explain the spring problems. I know this RC hasn't been well looked after, due to how dirty it was, properly set in crud under the engine etc... It's clearly never been cleaned under their, or on any of the chassis really, so it wouldn't surprise me if I do end up needing a new carb Quote Link to comment Share on other sites More sharing options...
Thunderwolf Posted November 17, 2013 Share Posted November 17, 2013 (edited) you can get kits to replace oll the gaskets and rubber parts yes. i know mmr have one for Edited November 17, 2013 by Thunderwolf Quote Link to comment Share on other sites More sharing options...
animal47 Posted November 17, 2013 Share Posted November 17, 2013 Check that there is no excess play in where the main shaft passes through the carb body as it will cause an air leak if there is a lot of slop here. Quote Link to comment Share on other sites More sharing options...
Oh How Original Posted November 17, 2013 Author Share Posted November 17, 2013 you can get kits to replace oll the gaskets and rubber parts yes. i know mmr have one for Quote Link to comment Share on other sites More sharing options...
Oh How Original Posted November 17, 2013 Author Share Posted November 17, 2013 Now I can't see anything particularly out of place here, but thought I'd upload a couple of pictures just in case anyone else can? I know it's dirty and it's about to be cleaned, but can't find my other pair of mole grips to grip the fuel lines Anyway, what do you lot think? Quote Link to comment Share on other sites More sharing options...
Oh How Original Posted November 17, 2013 Author Share Posted November 17, 2013 So I've got it off, given it the best clean I can with fuel lines still attached, everything seems to be returning better now, it needs a new gasket where the insulator block is. Also it appears it's a Walbro 218? Which I've never heard of before personally. Quote Link to comment Share on other sites More sharing options...
Oh How Original Posted November 17, 2013 Author Share Posted November 17, 2013 (edited) I think I've fixed the carb now, it's bouncing open a hairs width amount when you let the brake off, I've tightened the spring at the servo and it's helped, I've cleaned the carb up and it's very smooth now, I also noticed when putting it back together, their was almost a kink in the black fuel line that goes to the carb, which will surely restrict fuel going in? Which could explain the gradual revving after 5-10 seconds of being started possibly? What does anyone think of that? I've now very loosely carb tied it down so their is no kink, just a smooth curve. Hopefully that's it all fixed. Also found out the steering servo is a Hitec 805BB, which is nearly 26kg so I reckon that's strong enough for the moment. Edited November 17, 2013 by Oh How Original Quote Link to comment Share on other sites More sharing options...
Feedtheinferno Posted November 17, 2013 Share Posted November 17, 2013 See OHO see, you are updating the thread regularly. You are already on you're third page. Aren't you glad I forced you to start this thread? You are welcome 2 Quote Link to comment Share on other sites More sharing options...
Oh How Original Posted November 17, 2013 Author Share Posted November 17, 2013 See OHO see, you are updating the thread regularly. You are already on you're third page. Aren't you glad I forced you to start this thread? You are welcome Haha, got better replies than I was expecting, so don't mind keeping folk up to date Just hoping this has sorted the running issue, time will tell when my new pullstart and flywheel arrives. 1 Quote Link to comment Share on other sites More sharing options...
Feedtheinferno Posted November 17, 2013 Share Posted November 17, 2013 Damn I think I have a spare flywheel too Quote Link to comment Share on other sites More sharing options...
Thunderwolf Posted November 17, 2013 Share Posted November 17, 2013 Damn I think I have a spare flywheel too where were you when i needed parts 3 days ago lol Quote Link to comment Share on other sites More sharing options...
Oh How Original Posted November 17, 2013 Author Share Posted November 17, 2013 And me! I needed a flywheel as well I may need a new carb if my cleaning and re-adjusting hasn't worked, so if you'd consider selling it, drop me a PM with which one it is exactly Quote Link to comment Share on other sites More sharing options...
Feedtheinferno Posted November 18, 2013 Share Posted November 18, 2013 Did you sort the exhaust rubber in the end dude? I would like to know as I need to cut up my jetpro and fit one so in the likely event of a crash it doesn't ruin everything Quote Link to comment Share on other sites More sharing options...
Oh How Original Posted November 18, 2013 Author Share Posted November 18, 2013 Did you sort the exhaust rubber in the end dude? I would like to know as I need to cut up my jetpro and fit one so in the likely event of a crash it doesn't ruin everything I've not had any exhaust rubber issues? Confused... Quote Link to comment Share on other sites More sharing options...
Feedtheinferno Posted November 18, 2013 Share Posted November 18, 2013 That's a good point....what the hell am I going on about? Quote Link to comment Share on other sites More sharing options...
Oh How Original Posted November 18, 2013 Author Share Posted November 18, 2013 That's a good point....what the hell am I going on about? Quote Link to comment Share on other sites More sharing options...
Noj Posted November 18, 2013 Share Posted November 18, 2013 Dude, EPIC fail above....check the spelling In other news, it's not been running right? A second hand gasser? Bought by you? Well, I'll go to the foot of our stairs :-p Sure you'll get her sorted in time... Quote Link to comment Share on other sites More sharing options...
Oh How Original Posted November 18, 2013 Author Share Posted November 18, 2013 Dude, EPIC fail above....check the spelling In other news, it's not been running right? A second hand gasser? Bought by you? Well, I'll go to the foot of our stairs :-p Sure you'll get her sorted in time... I didn't make it, I just posted it And I think it was a simple case of the fuel line being kinked at the bottom of the carb, and also a lot of dirt on the carb, the engine note only backs up this theory, done quite a few adjustments, so just waiting for my new bits to arrive and a dry day and I can find out one way or the other. She was always going to get a new engine anyway so even if it's days are up, I'm not massively bothered, she just won't be finished as quickly. Quote Link to comment Share on other sites More sharing options...
Oh How Original Posted November 19, 2013 Author Share Posted November 19, 2013 Nice new flywheel and nice new pullstart! Quote Link to comment Share on other sites More sharing options...
Feedtheinferno Posted November 19, 2013 Share Posted November 19, 2013 Brilliant, now the thing we are all waiting on with baited breath. Does it work?! Quote Link to comment Share on other sites More sharing options...
Oh How Original Posted November 19, 2013 Author Share Posted November 19, 2013 Brilliant, now the thing we are all waiting on with baited breath. Does it work?! Just had her fired, engine is really smooth and nice, so I can't complain. I'm having one very minor issue (well two) first one being my dog bones are too small bahhh!! Secondly, after a good rev, she sits just above idle for a couple of seconds then drops down, the idle screw is all the way out and she's not exactly running lean, so that's something I need to investigate, although I don't think it'll be too much of a problem to be honest. Quote Link to comment Share on other sites More sharing options...
Feedtheinferno Posted November 19, 2013 Share Posted November 19, 2013 Remember the idle screw isn't the only part of the carb that affects the idle, if you have the screw all the way out, adjust the LSN as that will actually up the idle of the engine allowing you to get a nice balance between both screws. Quote Link to comment Share on other sites More sharing options...
Oh How Original Posted November 19, 2013 Author Share Posted November 19, 2013 Tried and it made it a little bit better, but then the idle was a touch higher. Their is a tiny little tear in one of the carb gaskets though, so that's probably the reason, but it'll do for now until I've got some money. Quote Link to comment Share on other sites More sharing options...
Feedtheinferno Posted November 19, 2013 Share Posted November 19, 2013 Well then adjust the idle screw in, allow the butterfly to close a little more using the idle screw and use the LSN to boost the idle. That will work Quote Link to comment Share on other sites More sharing options...
Oh How Original Posted November 19, 2013 Author Share Posted November 19, 2013 Well then adjust the idle screw in, allow the butterfly to close a little more using the idle screw and use the LSN to boost the idle. That will work That's what I tried bud, the butterfly goes fully back to it's original position Pretty sure it's either the exhaust gasket or carb gasket. Not sure which gaskets I actually need though, as this is a carb number I've never heard of Quote Link to comment Share on other sites More sharing options...
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