The $50 Cruiser air intake

[Trey]

So after spending waay too long modifying the stock air intake filter housing, I finally got a workable plan together and excluded it.

1) Stock air box, and breather from an older Briggs push mower.
2) Trimmed the stock plastic housing for depth...
3) And height. Turned out to be a waste of my 'Dremmel action grip' wrist action. Didn't use it, only modified it past the point of serviceability.
4) Needed a bracket- had some scrap+ Dremmel...
5) That will eventually become the air box bracket- just like on a carb in an old car or truck.

 

[Trey]

1) The air box bracket.
2) Had to shorten the carb bolts to exclude the stock air box.
3) The completed bracket. Probably a waste of time, but I ground the areas that may have impeded airflow. Typical effort where it's least likely needed.
4) Installed. The rod the wingnut screws onto got shortened some.
5) Had to modify the air box more than this to accomplish a fit, after ditching the stock air box completely.

 

[Trey]

1) After modifying the metal air box housing, I also had to match the plastic in-filter air feed tube (the end you can't see). I notched the top (of the visible side) in order to orient upon assembly.
2) Used stock filter material as a sort of gasket between air box and carb.
3) Installed. Shazam- One of a kind! Unless you build one too

Runs pretty good. Had to adjust mixtures though, and not sure that task has finished with me yet. Also still need a new filter element, and have to work out throttle linkage, and blow back tube.

Six hours of my life gone. That's not a misprint- and I love this thing!

 

[maniac57]

Very nice re-use. Pop a few extra holes in it for better airflow if needed. Should last much longer than a stocker before it needs cleaned.

 

[Trey]

So I was next door at the hardware store, wandering around in a fluorescent induced daze, lulled to browse by the mellow sounds of Kenny G or some such thing, when I saw it. The $5 fix for which I live.
In this case, a lawnmower air filter. It's supposed to be pushed into a tube off the carb, and strapped tight. I had to trim the outlet to fit the face of my carb, and drill a hole in the end to mount it onto my car-like breather attachment point. That bracket also had to be modified by slotting the carb bolt holes to allow for installation.
I have to get the carb just about on, put the filter on the bracket, then work the assembly onto the carb bolts, finally tightening with a wrench. There's only about 2mm clearance.
I'm convinced that my bike just got cooler! However, I wouldn't recommend this one. It looks like it may be a pain at some point... but it's cool...

1) That's the final product. Looks good with the fuel bowl methinks.
2) This gap corresponds with the areas I ground down on the bracket in my earlier post. Any opinions on this?
3) My calibrated eyeball says 2mm clearance.
4) Same air gap as left side. Had to re-jigger the throttle cable bracket as well. Everything is sooo tight.

Runs good. Tweaked the air/fuel mix a touch.

 

[Trey]

I seem to be having some trouble with engine bogging upon throttle. I've searched and it could be air restriction. In post 2, pic 5 is of the filter attachment point. Could this bracket be restricting air flow that badly?

 

[Dan]

Not sure Trey. Have you tried a very short ride to rule out air restriction?

Scares me to run any engine with out an air filter but would be a good indicator.

 

[Dan]

Forgot to say, that is uber cool. the stock filters really do make em look like re-purposed lawn equipment engines.

 

[Mr. Minecraft]

Let me start by saying that I love it when I see people custom make things for their bikes. I like the creativity you had to use to make this work.

Now I must ask, how does this compare to just buying a V-stack and using one of the many readily available air filters from DDM or SBP? Using a V-stack and aftermarket air filter is defiantly cheaper, so why should one make their own setup rather than buying one?

NOTE: I am in no way talking against what you created

-Chris

 

[Trey]

Now I must ask, how does this compare to just buying a V-stack and using one of the many readily available air filters from DDM or SBP?

A simple matter of small money- big time. The filter was about $5, the bracket and fitting was time, (way too much time) but I'm happy with it. I lean toward building everything I can. I don't know how to order online yet, so I have a buddy do it, and it's just one step I can cut out sometimes. There are some awesome ones' you can order, but this is old looking.

Dan- I ran it with no filter, no muffler, no filter and no muffler etc. Seems to be a matter of air somehow. Get's too much at high throttle?

 

[Dan]

am thinking carb fuel bowl might be gumming up or is a simple clogged fuel filter.

Is maddening when a new symptom happens just after you change some thing. But if the problem persists with out the new air filter, I would go threw the regular stuff in the fuel delivery chain.

I know what you mean Mr. Minecraft. The buy the pretty, in the box part Vs. the DIY experiment. But just so much more fun with the DIY. Always felt uneasy when people would ask if i "built that" with the Chinagirls. Pretty much I just secured it to a bicycle. Not that, that is in any way a small feat depending but still, never felt like I had "built" any thing and was fluffing no matter what the answer.

I have the worlds butt-ugliest muffler. DIY from flange to end exaust, the worlds ugliest motorized bicycle muffler. Other mufflers make fun, beat it up and take it's lunch money on the way to school. It is a poorly welded flange, bent electrical conduit and a plumber's rubber blow-bag used to unclog drain pipes. (Has a really cool sound) So ugly, no one else I know has tried it. But was a successful "see if this will work" thing. I really did expect it to go BOOM! Even went back in the house to warn folks to expect another, err A loud noise. LOL. But the dang thing worked great.

har, sorry about the ramble. Coffee is kicking in.

vid of rubber muffler; http://s293.beta.photobucket.com/user/dan3xd/media/RiverSide/1021001717.mp4.html

 

[Trey]

I will have some time for this now th

 

[happycheapskate]

I have thought about using a travel soap-box, with holes drilled in the back (inner half), and a large enough hole whittled out for the carb.
Square foam filters are available commonly enough. lawnboy makes some for a few bucks.

 

[Trey]

I have thought about using a travel soap-box, Square foam filters.

That's a great idea! Why not? Or something like that... camping supply stores and the like have a bunch of stuff that might work. Your name works for you my friend My montra is; need it, make it, got it.

 

[Dan]

" need it, make it, got it." That is awesome Trey!

 

[happycheapskate]

Could the filter be saturating with fuel mix?

 

[happycheapskate]

I'm not sure which carb you have, but the NT carbs have a jet/hole in them that needs a small amount of restriction to idle right. (runs badly without filter except under fast throttle position). I put one on a 5hp briggs flathead and couldn't figure out the rough idle until I put the filter back on, then it smoothed out.

I saw,somewhere, an HT carb filter box made from a metal toothbrush holder (looked like a small vase with 1/4" holes drilled all in it to let filter breathe). It was stainless steel and looked factory made.

 

[Trey]

Posting from my phone so will be short. I intend to work on it over the weekend so I'll know more. It's been a couple months since I've touched it but there was not gas in the filter. Lack of proper air flow was on my mind at the time though. Thanks for the interest I will need some help

 

[Trey]

OK! Finally got some time. Thanks to you guys for being patient
Cleaned and gaped the plug (was running rich), removed and cleaned the carb (gas seemed a little oily, I had put in some Seafoam), cleaned filter, flushed tank, put in fresh gas. Replaced what appears to be the crankcase vent tube, back into the air filter. Turned air/fuel mixture screw out 1 turn, then 1 1/2, then 2 etc etc, while sitting, and while driving, and it has no effect other than at one point I could smell gas briefly. Turned idle screw in 2 turns to try to keep it running (barely works). Put stock muffler back on (not clogged), and it runs. Sort of.
If you pedal up to speed it will keep you going for a few hundred feet on a flat, but the drive effect fades. The top power output of the motor seems constant- what would normally be maybe 1/3 throttle. It will not idle without giving it some gas, but it did when I first put it back together. Rode it about 1/8 mi.
To describe it in a word; retarded. It makes less noise, builds less RPMs, and produces less power.
The actual throttle lever, cable, and hand control are all operating properly.
I'm starting to wonder if it might be something in the engine, and not air intake...
Here's what it looks like now.

Right now... going to reset carb properly, see if air filter is too restrictive, and if float leaks.

Update- carb set, air filter and float are good to go, runs great! (My fuel screw is out 3 turns, and my idle screw is in 1 turn.) I believe the crankcase ventilation tube being off was my problem. Huh...
Goin for a ride

 

[wheelbender6]

Some members have made some nice looking air cleaners from a tuna can.