Diagnostic time (again) :(

[MotoGod]

I think your problem previously was an overall "too lean" tune. Which basically makes the idle screw useless. If it's running really well on the top end and revving good...with good smoke. Then start mucking with the LSN. I bet you can bring her back in tune just with that now ;-)

Once your gap is set....you should just have to inspect it every now and again really. I check mine when I pull the filter off for replacing/cleaning.

If your temps are still at 190, you also have room to lean the HSN as well. Might help you out a tad. I hate to see engines running under 200ish personally ;-)

 

[Mickstix]

Yea, I'd like to see it in the 210-220 range myself! It's rained the last 2 days so no fun was had.. Hopefully tomorrow I can get back to it! Hey, how often do you clean your airfilter, when running "on road" or in the grass, only?? I clean it every time if I get in the sand or dirt, but not sure what to do when I'm just runnin it up and down the street and across the yard every now and then? Thanks!

 

[MotoGod]

I only really drive at the track. Some days are dustier than others....I just visually inspect it. If the outer filter is covered....I change both typically. The inner filter usually has nothing on it...but I swap em out as a pair anyway.

I just toss the dirty ones in a bag and clean em every once in awhile....4 or 5 at a time...then re-oil em and get em ready for next time. Most racers just throw em away though...I have had good luck just cleaning mine thus far.

 

[Mickstix]

Sounds good, thanks!

 

[Mickstix]

Ok, got the .28 running pretty good now! Now I'm starting to breakin this little .18 I have and I'm wondering about the "heat cycle" breakin method.. I'm pretty sound on the method, but the engine isnt getting very hot just putting around? (appx. 175*) I dont want to run the rpms up much since it's new, but read that the temps should get up to around 205* before letting it cool off? Should I just lean the HSN until the temps get up, or how do I go about getting it hot enough w/o revving the car much? Thanks as always!!

 

[olds97_lss]

Usually, the first tank or two, temps don't hit 200F due to the air gaps and whatnot as the piston seats into the sleeve. As it wears in a bit, it fights a bit harder and your temps go up. I usually don't see 210F until at least 200-300 cc's are through the engine. Sure, you could get that within the first 50cc's, but you'd have to lean it out pretty good and run the risk of hurting it.

All depends on the engine. I've had some that hit 200 by the end of 100cc's. Others that take more fuel to do the same.

 

[MotoGod]

+1 on what olds said. usually you want to start @ 170-180 for the first tank....run it...let it cool. Then go up @ 10 degrees by leaning the LSN (since you aren't really throttling it too much) for another tank....then on tank 3 or so...get it up past 200, but not quite past 220. Just heat cycle it a few times....then start to slowly tune it and by tank 4 or 5 I had mine on the ground driving it. Some guys drive from Tank 1 and that's cool too ;-) There are 4 billion break in methods out there....pick one and run with it.

 

[olds97_lss]

Yeah, I gently drive mine starting at tank 1. I don't let it sit and idle. Seems silly to let it sit there and load up. I break in on concrete, not grass, to limit rolling resistance. I just don't run with much throttle until I get up around tank 5 or so (500cc's through the engine). Even then I'm very careful and don't really start tuning for performance until I get 1500cc's through them.

I do adjust the HSN and LSN accordingly a bit starting from tank 1. Nothing to aggressive. Just a to lean an hour or so to get temps up and keep the engine from flooding/hydro locking on me. Running too rich causes the engine to work a lot harder. Fuel doesn't compress, so an overly rich engine runs the risk of crushing plugs or worst case busting con-rods.

 

[Mickstix]

Excellent info, thanks!! I'm also gonna drive mine from the start.. (Short back-n-forth's on the driveway) I'll lean it out a little more tomorrow. So far I've only done 2 cycles (appx. 1 tank/75cc)

 

[MotoGod]

Oh yeah and if you lean the LSN during break in to get the temps up...remember to fatten it back up once you start putting a base tune on it or it will throw everything out of whack. I kept mine at a high idle for break in as well....which I brought back down when I put her on the ground to start tuning.

 

[Mickstix]

I have a question.. lol.. I did some searching tonight, for "during breakin-engine dies as soon as glow ignitor is removed" Well, my engines are probably to far into the breakin stage to find this out, but in 2 different articles I read, it said if this happens to lean your HSN (Yes, High Speed Needle) and it should stay running.. I always thought you would lean the LSN, since your just tryin to get it to idle at this point?? Does anyone know if these were typo's or is leaning the HSN actually the correct way to solve this problem?? (And were also assuming the glow plug is not the issue) But I know when leaning the LSN to get it to run, the idle goes way up and you can get into problems like I was having earlier in this thread.. So, just wondering what the proper fix is, when breaking in a motor and it wont stay running when ya pull the ignitor.. Thanks, as usual, for your guys opinions!

 

[MotoGod]

Usually, if it dies when you yank the ignitor it's the plug, but it's also possible that there is just too much fuel in there....so leaning it does help. Leaning the HSN affects BOTH needles so it should work. Remember the HSN controls overall fuel delivery to the carb throughout ALL throttle positions. The LSN only affects the fuel delivery from closed throttle to @ 1/4 throttle....but the LSN also regulates the fuel AFTER it has already passed through the HSN.

 

[Mickstix]

Yea, I understand the theory. I was just wonderin if this was some sort of fupa that went against it.. These are with brand new SH.18 motors.. Seems they've changed plugs or something in the engine to make them not run when new, with the stock needle settings.. Another guy was having the same deal so I figured Id research it.. But anyway, I put the .18 I've been breaking in, back to 3 turns out (basically flush) on both needles today, and it did the same thing. (died as soon as I pulled the ignitor) so I tried the HSN lean, and leaned it almost a full turn and it idled for a few seconds w/o the ignitor and then died.. So after tryin that a few times, I went back to the LSN and that got it to run again.. Also, with leaving the LSN at 3 out the thing wont get over 150*, doing these < 1/4 throttle pulls, even with the HSN leaned a full turn.. So I think it's best, for heat reasons, to just lean the LSN and let the idle run high during breakin.. That lets it get up to near 200* for the 5 minute "heat cycle" session.. Thanks bud, for the continued info and help!