Post by Evilgenius on Sept 27, 2011 18:01:17 GMT -6
OK...so, here's a little follow-up on that o-so-crappy air filter review. If you've got some free time and are feeling 'wordy', pull up a stool. 
Trying to do it all on a budget (virtually nothing, really), I set out to do a general air/jet/exhaust upgrade on my '07 Lifan 'Calalina' 150.
After much frustration and silicon, I managed to get the air filter in temporary usable status. Fugly, but now serviceable. Of course, it would not fit straight on to the carb, necessitating an intake tube.
And so, I set off to Ace Hardware. Can't say how much this place does for me in way of parts - I'm actually thinking an Ace sticker might find itself a home somewhere on the scoot. ;D Being a DIY type, with no real alternatives in town, Ace is quite literally "the place".
A rubber boot, a PVC elbow, and a piece of 1-1/4" curved PVC later, I've got a nice intake arm stretching around the left side where the filter can get some fresh air. Filter socked right on there perfectly. Used a shiny exhaust hanger upside down as a foot for the arm. Should hold the carb up as a bonus. Would'a looked good too, if it weren't for the functionally necessary but aesthetically displeasing silicon all over it.
Ultimately, that is of little consequence however; the filter pod is still safely behind the skirt when reassembled. I will be purchasing another (and hopefully much more sturdily-constructed) air filter to replace it, which will be similarly hidden. I'll know it looks better though.
New jets came via Absolutely Scooters. Pilot swapped from 36->38 and main swapped from 105->115. Love the design on these! The main has an extra 1mm 'neck' above the threaded area below the cap, and the pilot just has an extended barrel, both for deeper reach into the float bowl. I can't say as I have any reason to think the stock jets were sucking the bowl dry beforehand, but it does make sense from an engineering standpoint IMO, and I like that.
We can make him better than he was. Better...stronger...faster...
The stock airbox was removed. Hated that damn thing anyway.
Vent line's got to go somewhere, though! A while back, I came across one of those aluminum drink bottles in a shade of blue suspiciously similar to my scoot's paint job. I took this, and drilled two 1/8" holes in the cap, and stuck 2 weedeater fuel filters in the holes. The cap is hollow, so I just made 1 big vent hole to the 'inside' to feed both of them. The back (botttom) of the can was precisely drilled and a 10mm stainless quick disconnect was screwed in (the hose from the valve cover predictably followed). Some bigass hose clamps on the back frame, and I have a big phat catch can in matching color, vented and plumbed for ease of eventual dumping.
Getting a first good look at my intake, I was pretty disheartened. The intake bore was forged. Poorly.
This will not do! Took a carbide burr and took out the parting flash, with further finishing done by stone and heavy-duty nylon wheels. End result was an incalculably smoother bore wall, as well as an approximate 1mm increase in intake diameter. ;D Nothing wrong with that. Securely wrapped the elbow with good electrical tape as PM against dry rot-cracking due to the air box removal.
I figured that if I was dumping this much more 'in', logic only dictates that the 'out' needs some help too. The header pipe was pretty clutzily welded; I'd previously removed the giant weld boogers, but took it a little further and drimmel-trumpeted the end this time. New exhaust gasket required, of course. Reduced back pressure was provided by drilling out the stock muffler rivets, removing the sleeve/cap, sawing off the pigtail 'straight', and putting a couple of gratuitous 1/4" drill holes on either side of the (now circumcised) pigtail, through the back wall of the muffler only. Riveted it back up with the rivet gun I inexplicably purchased several years ago and had never used, so that's always good too.
Only downside to this I saw was that the front end rivet bottoms are trapped inside the muffler now. Oh well...can't win 'em all. 
A few miscellaneous tidbits while I was at it: the Majesty body types like this make seat bolt removal a huge PITA. This can be dealt with by clipping a couple of notches in the plastic to get a socket in at them, instead of wasting time and bolt corners wrenching. Once the seat's down, the notches aren't visible anyway. Some new hosing and a B&S fuel filter were added too, along with a fresh sidegapped NGK.
And so, after reassembly...she fires right up. Beautiful!
Started adjusting after warmup...set the fuel/air and took off for a test ride.
Sound from the exhaust is OK. Little louder, but about as expected. More putt-puttier also, which I'm not sure that I like, as that indicates a 'dead spot' of flow in-between puts. Not cool. Will have to figure out if I want to keep this way, or put some bolts in the holes. (Hint: I've already got the bolts ready.)
Performance not quite what I was expecting. Idle is OK, takeoff is OK, but cranking on the throttle to WOT produces a mighty unseemly bog. Midrange power is crap, and the engine seems to be 'fighting itself' to power through it. Once it gets to top end, it smooths out and seems to do OK, although top speed is not quite as good as previous (I'm attributing this to power loss as it's fighting through the bog).
Swapped to a new, unmolested NGK just in case my side gap had somehow gone hiedously awry (it hadn't). Now to figure out exactly who's not playing nicely here...
Examining my old airbox, I can't say as I think that there was much restriction there. My ghetto intake tube *might* drop the effective ID a little bit, but surely not enough to cause a throughput issue. It doesn't seem to be fighting for air, anyway. It's about as free-flow as free-flow gets.
Ditto for the exhaust - theoretically, the restriction was mostly in the header pipe itself. Pigtail was only 2mm smaller than the header.
My current thought is that the larger pilot is overlapping with the larger main in the mid-throttle and flooding it out. Experimentally, leaning the pilot seemed to help this a bit, but I'll have to pull the tank and/or carb to lean the needle on the main, which is more PITA.
I haven't ruled out the exhaust, either. I may have got a little too enthusiastic with the drill and dropped back pressure too low, although I don't think this is likely. Possible though.
All this being said, I'd welcome any opinions as to your professorial thoughts on the matter.
Yes, I'll try and get some pics for all you scooter p0rn junkies. ;D
Trying to do it all on a budget (virtually nothing, really), I set out to do a general air/jet/exhaust upgrade on my '07 Lifan 'Calalina' 150.
After much frustration and silicon, I managed to get the air filter in temporary usable status. Fugly, but now serviceable. Of course, it would not fit straight on to the carb, necessitating an intake tube.
And so, I set off to Ace Hardware. Can't say how much this place does for me in way of parts - I'm actually thinking an Ace sticker might find itself a home somewhere on the scoot. ;D Being a DIY type, with no real alternatives in town, Ace is quite literally "the place".
A rubber boot, a PVC elbow, and a piece of 1-1/4" curved PVC later, I've got a nice intake arm stretching around the left side where the filter can get some fresh air. Filter socked right on there perfectly. Used a shiny exhaust hanger upside down as a foot for the arm. Should hold the carb up as a bonus. Would'a looked good too, if it weren't for the functionally necessary but aesthetically displeasing silicon all over it.
Ultimately, that is of little consequence however; the filter pod is still safely behind the skirt when reassembled. I will be purchasing another (and hopefully much more sturdily-constructed) air filter to replace it, which will be similarly hidden. I'll know it looks better though.
New jets came via Absolutely Scooters. Pilot swapped from 36->38 and main swapped from 105->115. Love the design on these! The main has an extra 1mm 'neck' above the threaded area below the cap, and the pilot just has an extended barrel, both for deeper reach into the float bowl. I can't say as I have any reason to think the stock jets were sucking the bowl dry beforehand, but it does make sense from an engineering standpoint IMO, and I like that.
We can make him better than he was. Better...stronger...faster...
The stock airbox was removed. Hated that damn thing anyway.
Vent line's got to go somewhere, though! A while back, I came across one of those aluminum drink bottles in a shade of blue suspiciously similar to my scoot's paint job. I took this, and drilled two 1/8" holes in the cap, and stuck 2 weedeater fuel filters in the holes. The cap is hollow, so I just made 1 big vent hole to the 'inside' to feed both of them. The back (botttom) of the can was precisely drilled and a 10mm stainless quick disconnect was screwed in (the hose from the valve cover predictably followed). Some bigass hose clamps on the back frame, and I have a big phat catch can in matching color, vented and plumbed for ease of eventual dumping.
Getting a first good look at my intake, I was pretty disheartened. The intake bore was forged. Poorly.
This will not do! Took a carbide burr and took out the parting flash, with further finishing done by stone and heavy-duty nylon wheels. End result was an incalculably smoother bore wall, as well as an approximate 1mm increase in intake diameter. ;D Nothing wrong with that. Securely wrapped the elbow with good electrical tape as PM against dry rot-cracking due to the air box removal.
I figured that if I was dumping this much more 'in', logic only dictates that the 'out' needs some help too. The header pipe was pretty clutzily welded; I'd previously removed the giant weld boogers, but took it a little further and drimmel-trumpeted the end this time. New exhaust gasket required, of course. Reduced back pressure was provided by drilling out the stock muffler rivets, removing the sleeve/cap, sawing off the pigtail 'straight', and putting a couple of gratuitous 1/4" drill holes on either side of the (now circumcised) pigtail, through the back wall of the muffler only. Riveted it back up with the rivet gun I inexplicably purchased several years ago and had never used, so that's always good too.
A few miscellaneous tidbits while I was at it: the Majesty body types like this make seat bolt removal a huge PITA. This can be dealt with by clipping a couple of notches in the plastic to get a socket in at them, instead of wasting time and bolt corners wrenching. Once the seat's down, the notches aren't visible anyway. Some new hosing and a B&S fuel filter were added too, along with a fresh sidegapped NGK.
And so, after reassembly...she fires right up. Beautiful!
Sound from the exhaust is OK. Little louder, but about as expected. More putt-puttier also, which I'm not sure that I like, as that indicates a 'dead spot' of flow in-between puts. Not cool. Will have to figure out if I want to keep this way, or put some bolts in the holes. (Hint: I've already got the bolts ready.)
Performance not quite what I was expecting. Idle is OK, takeoff is OK, but cranking on the throttle to WOT produces a mighty unseemly bog. Midrange power is crap, and the engine seems to be 'fighting itself' to power through it. Once it gets to top end, it smooths out and seems to do OK, although top speed is not quite as good as previous (I'm attributing this to power loss as it's fighting through the bog).
Swapped to a new, unmolested NGK just in case my side gap had somehow gone hiedously awry (it hadn't). Now to figure out exactly who's not playing nicely here...
Examining my old airbox, I can't say as I think that there was much restriction there. My ghetto intake tube *might* drop the effective ID a little bit, but surely not enough to cause a throughput issue. It doesn't seem to be fighting for air, anyway. It's about as free-flow as free-flow gets.
Ditto for the exhaust - theoretically, the restriction was mostly in the header pipe itself. Pigtail was only 2mm smaller than the header.
My current thought is that the larger pilot is overlapping with the larger main in the mid-throttle and flooding it out. Experimentally, leaning the pilot seemed to help this a bit, but I'll have to pull the tank and/or carb to lean the needle on the main, which is more PITA.
I haven't ruled out the exhaust, either. I may have got a little too enthusiastic with the drill and dropped back pressure too low, although I don't think this is likely. Possible though.
All this being said, I'd welcome any opinions as to your professorial thoughts on the matter.
Yes, I'll try and get some pics for all you scooter p0rn junkies. ;D
