engine troubleshooting / carb setup

[rcrallyfan]

Hi all,
a couple of drives ago the engine began to die on idle now and then, and finally today for the first time it would not restart. It's as though it is getting no spark. Any ideas what to check first based on probability are most welcome Also advice is requested on setup / tuning of the carb on the stock 30cc engine.

[fsmt4wd]

put a new plug in there, ngk, and the stock carb is rubbish, so get a nomal walbro carb in there, use stock carb settings to begin with and then tune accordingly, tune to the highest revs, oh and what airfilter are you usiing??

[sickboy]

well if its wat i think it is then take the engine apart because it sounds like its dead to me as this happened to my fs engine to and when i took it apart the thing was a mess all the bearings were damaged pull rod bent its only my idea but it might not be as bad as i say

[338lapua]

I'm with sickboy , sounds like compression a friend of mine had his lean out and distroy the piston and head . good luck.

p.s hope that inner body cover didn't overheat that engine??

[rcrallyfan]

fsmt4wd I use a two-stage foam air filter with metal casing and Outerwears cover

338lapua No question of overheating or even near that, especially with about 0C temps around here for some time now. The inner is there mainly to keep the snow and wet earth out of the electronics and air filter.

With barely a gallon of gas through the engine and no hard revving, it would be strange if the engine was actually dead. Particularly as it always started easily on the first or second pull. When it began dying on idle, it still worked perfectly on high revs. Compression feels as new on the pull start. So I would bet on carb / plug problems at this point. Hope to be able to begin looking into it on Monday.

[rcrallyfan]

Good news everyone : I took out the stock plug and put in a new NGK, and guess what? The engine started on the first pull. Wow, it's good to be back on the road ;D

[fsmt4wd]

;D ;D

[sickboy]

well i real happy ;D ;D for you so the plug was foweld up then well thats got to be this quickest fix in rc world lol but i still cant belive that the fs 30cc is still going then how many tanks did you go threw till now

[338lapua]

glad to hear a cheap fix for a change .

[rcrallyfan]

Well. the new plug did not help for long, unfortunately. The engine soon stopped starting again.
Although the engine has barely 4 liters through it, and pretty mild driving at that, I now determined that the compression is gone. It became clear only after I took off the flywheel cover and compared turning the wheel by hand with another engine, which is known to operate. Will probably leave it with some workshop on Monday, and see what they find out.
Meanwhile, I hoped I would be able to drop in another engine, a 23 from my Smartech Spider / Carson Attack = FG Marder clone. Unfortunately, the Attack engine does not have proper mounting holes for FS / MCD models, those on the flywheel cover at the bottom. In theory, this could be resolved by swapping the flywheel cover from the FS engine. However, to my frustration, the FS cover is NOT compatible. It is considerably shallower, so it locks the flywheel on the other engine.
The question now is: are there any adapters available for mounting such engines on FS / MCD cars, or is DIY the only way to go?

[fsmt4wd]

bad news.. well we have mounted a zen with the fs casing and it worked so you could be lucky and just purchase a CY/zen casing, but maybe the engine is differnet on you 23cc, i think i remember someone saying that smartech makes their engines in house and the holes of different, so no bigger heads can be fitted etc..
IMO if ya can get the money together invest in a zen27 and ya will be happy and the fs casing fits..

[rcrallyfan]

I provisionally mounted the Spider 23 on the FS, using just the gear support bolts and a foam support at the other end, works fine. Ultimately I will be opting for a ZEN G270, btw the FS engine case seems to be a direct clone of the Zen. And yes, the Smartech engine is different in respect of the fan wheel and cover, the fs/zen cover fits the holes but locks the fanwheel on the Smartech engine, as it is shallower that the Smartech cover, whose fanwheel protrudes more outwards.

I noted that something must have been wrong with my FS engine right from the start, because the Smartech 23 sounds better (more natural), has stable and reliable idle and more punch. Possibly the head gasket had a minor leak, I hear that can cause easy starts (mine always started on the first pull) coupled with poor performance. Eventually the leak may have grown and reduced the compression below firing level. Just a theory.

I have just discovered another annoying incompatibility between the FS/Zen and Smartech engines: the pullstarts cannot be swapped, because the Smartech one has slightly different dimensions and the bolts don't align.

[rcrallyfan]

You're not gonna believe this:
This morning I took the FS engine to my local Husqvarna dealer, hoping they would be kind enough to look at it, as they are closest to where I live. The guy looked the engine over, pulled on it a few times, said it looked and felt fine to him and he found it strange it wouldn't start. He took out the plug (the new NGK, which I had eyeballed and saw it spark). No spark. What about the coil? He took one of his plugs: sparks fine. All right. I went home, checked the NGK again: no spark. Took the stock plug that had been in there previously: no spark. Nada. I had checked and rechecked both of these plugs a few days ago and they definitely worked. Took the plug from the Smartech engine. This one sparked fine. Screwed this plug in, put the FS engine back in the car. It started happily and I dried half a tank without any glitches before it got dark. What is the probability that 2 plugs, including one brand new, die right after you eyeball them and verify that they spark? Needless to say, I'm happy as things turned out - no immediate need to fork out cash for a new Zen

[speedyd]

thats kinda freaky, i have had bad plugs before. but never two in a row!

[hoppy]

i have heard elsewhere that the fs coil, lead and plug can be unreliable... but who knows- if it works now, fang it some! ;D