Nobody cares about aircleaners.

[ZekeNoScooter]

I just skimmed thru about 100 threads and found 1, only 1, about air cleaner s. I've been at this version of the old Huffy for about 6 months. Getting a lot of buff out. But I've never been able to get that top end, flat and level maybe 27. Downhill, tow truck and a trail wind, got her up to 31 once. I upgraded this build with a 36 and a hub adapter, specifically for the top end.
So, the other day I'm fiddling with something and I notice the air cleaner is just sorta hanging there, not tightened. (Frame's real tight.) So I'm like 2 blocks from home so I just pull it off and , WHOA! ! ! Holy crap! That's where my top end has been hiding. In the apt cleaner!
Seriously, I got 6 or 7 mph, and what feels to me like at least 20% increase in power.
So know what do I do? Aren't a lot of options in air filtration. Oh hey, this'll help. I'm running a dellorto clone on a stock PK Wildcat. Crescent Moon expansion/muffler.
Is the solution in the carb running rich with the A/c on? So if I lean out the jet. ..

 

[bairdco]

There's a bunch of air filters available for those carbs. Find a free flowing one.

You can run it without one, but you risk sucking up dirt and water, which can clog your jets, or worse, if you ride in dusty, sandy areas.

Jetting will help if your air filter already flows good. Go smaller on the main jet, or move the clip on the needle up.

 

[kelly dean]

I've run a couple of SHA dellorto clones they both needed rejetting to get decent performance the SHA is the big 60mm outside diameter for the air cleaner and thee are a number of options, Ive used the wire and foam sock type of air cleaner and they seem to breathe well the picture is of a 40mm i bought for something else but ive had them for the SHA clone too amazon and shop around pictured unit was about 8 bucks.... kelly

 

[ZekeNoScooter]

Hey

I just skimmed thru about 100 threads and found 1, only 1, about air cleaner s. I've been at this version of the old Huffy for about 6 months. Getting a lot of buff out. But I've never been able to get that top end, flat and level maybe 27. Downhill, tow truck and a trail wind, got her up to 31 once. I upgraded this build with a 36 and a hub adapter, specifically for the top end.
So, the other day I'm fiddling with something and I notice the air cleaner is just sorta hanging there, not tightened. (Frame's real tight.) So I'm like 2 blocks from home so I just pull it off and , WHOA! ! ! Holy crap! That's where my top end has been hiding. In the apt cleaner!
Seriously, I got 6 or 7 mph, and what feels to me like at least 20% increase in power.
So know what do I do? Aren't a lot of options in air filtration. Oh hey, this'll help. I'm running a dellorto clone on a stock PK Wildcat. Crescent Moon expansion/muffler.
Is the solution in the carb running rich with the A/c on? So if I lean out the jet. ..[/QUO

 

[indian22]

All good stuff guys. In the old days, I'm not talking my old days 50 plus year ago, but from the start of motorcycling, de-coking the head and piston was common maintaining of 2 and 4 cycle engines, just cleaning the carbon buildup off the top end of engines. Seldom done on engines these days by most but I do it on my engines as a part of periodic top end tune up especially on my 2 cycle motors and always notice a power improvement. The reason I mention this is, as you've noticed Zeke, not much is ever said on most forums about air cleaner degradation causing power loss or preventing the engine from running at top form. Newbies tend to screw around a lot with carbs without consideration of how the changes effect or are effected by air restriction, spark advance, compression, fuel mix,( 2 cycle port timing) & expansion chamber design parameters. Zeke once you discovered the improvement you asked the proper question about re-jetting and how much more or less would be required. Though I'd also guess, as was suggested, that you need to jet down, but before jetting down I'd chop the plug after a good hard ride and see what the plug says you should do. It will tell you if you are lean, rich or right on. Then make the proper carb adjustment, jetting change on the Dellorto 'cause they don't have a clip. Re-run the engine and read the plug again & again till you get it right. I tend to set up a little rich but not much.

You mention changing to a 36 tooth sprocket for speed & that's ok, but I've seen many low power 2 stroke engines that actually dropped significant speed when changing to 8 or ten tooth smaller final cogs, especially running certain expansion chambers. Years ago I had a 66cc engine that demonstrated this in a very dramatic fashion. With a 38 tooth rear it would only reach 7,000 rpm and I could never get it to come up on pipe. After trying every trick I could think of tuning wise I switched to 44 tooth and it pulled to over 10,000 rpm and came on pipe like I found another gear & smoothed out. Just an example of cause and effect. After that ride I chopped the plug and I was still running a little too rich & had to jet down a couple of thousandths. One change leads to others when fine tuning.

I tune to get the performance I like for all around riding...not top speed, but when I have gone for speed only I usually found that the plug read perfect just after speed runs, but in daily riding it was way too rich & 4 stroked a bit till mid range and from there on up it was fine.

These little engines are simple but like what they like tuning wise, like little children they don't react well to peas and green beans, but prefer ice crème.

Rick C.