'03 Trauma Triple Plated AV Now

[Trauma]

I have been trying for 3 weeks to get these pics on here. If this works, I will give a full narrative of the how-to. I built it with $3.50 worth of metal from Home Depot and JB weld ($6.00). So far the thing has been working great. The true test will be a 300 mile poker run this weekend. ?Pictures!!

Let me know if this does not work!

[jsmith811]

What if a small piece of the JB Weld comes loose and goes in, I read about that happening on another thread... over 500 in damage.

[av]

Trauma - it's not as pretty as the real PowerNow but well done! :D

I like how you use the tabs to keep the avNow from rotating I hope the JB weld holds together for you - if you cleaned the surfaces well they should hold, perhaps the other person didn't use enough glue or the surfaces were dirty hence the glue didn't stick well. It would be best if the plates/tongues were somehow welded on the ring as well as the round plate that keeps the whole thing from rotating. If you can make it for cheap, some TTers may want to buy it from you to try - I know it takes a lot of time to make these things - very inventive of you ?

Have you noticed any differences in the performance of your 03 WR250F using the avNow mod? Any jetting changes needed?

[Trauma]

It starts up easier, luggs better with low rpms and seems to respond with more snap down low. I have not noticed any top end loss, although I don't spend much time up there. I am still working on an airbox mod, which I think will allow it to do even more. I have not changed the jetting from stock. (I am essentially at sea level.) I may need to change jetting after I get the airbox opened up some more. I am planning on the 12 drill univent mod tonight similar to Brobixr's.

[tiny30]

Trauma it looks as if your outer ring is copper and your plates are aluminum. For my plates I used thin galvanized sheet metal from a heating and cooling company,the stuff used for duct work in a house. Then you can solder the plates to your outer ring with a low temp solder. I used a 63/37 solder with a melting point of 361 degrees F. I have a little more trust in this than jb weld. Just an idea.

[Trauma]

Interesting thought. The plates are from a 69 cent Home Depot shingle. The ring is from a copper 2" pipe joiner. It is just the size to fit snuggly in the rubber airboot. I was contemplating the soldering idea, but was also concerned about the low melting point. It should not be that hot there, but a few backfires timed just right could cause problems. It might be safer than the JB but then again it might not. The plates are big enough, that they themselves won't get through the carb in a worst case scenario. If pieces of the JB broke off, they would be a problem. The JB is pretty thick and solid though. The only sketchy part was the weld of the pipe to the front circular flange. Any probs there would be trapped outside of the pipe anyway and really wouldn't make it into the airflow traffic.

[Trauma]

Just to update.... Last weekend rode the Nevada Mystery 250 which is a 250 mile desert enduro ride. About 20 miles into the ride and after 7 river crossings, I noticed a slight drop in rpm when I went from 3/4 throttle to WOT. This seemed a bit mysterious and I was thinking it might be water related or altitude related. I was planning on tweaking the fuel screw the next time we stopped for a moment. About 10 minutes later, I had a sensation of my throttle being stuck. The throttle at the handlebar turned fine. With the clutch in, the bike wanted to rev to the moon. I stopped it and restarted with the same result. With the bike off, turning the throttle I could hear the slide moving up and down. Tried messing around with the fuel screw and idle, did not help. The airbox was dry. I concluded that it must be something with the AV now. I pulled the airboot off to find all three plates flopping around in the intake bell completely unattached to the copper ring. The jb weld had not held. Now, of course I was paniced that bits of JB weld had found its way into the engine. I pulled all of the metal pieces out and put the boot back on. Once I got the idle screw readjusted, the thing started up and ran just fine. Actually better than it had been before things went sour. I think that the top plate must have gone first and was obstructing airflow early on. Ultimately they all went.

I am now thinking of getting a power now and feeling lucky, very lucky, that I did not ruin my engine with the JB Weld. I still don't want to cut into the metal of my carb as others have done for the '03 mod. I will probably fork out the cash for the comercial one unless I come up with a better, SAFER design in the meantime. ?

[av]

Thanks for the post - that's traumatic This is the second failure reported using JB weld for the avNow - people should stop using this glue for this application or if you have JB weld in your venturi - fix it now!

Seems like the best bet is to cut tiny slits into the venturi to hold the plates in place for the 03s, people who have done that for their 03s have not reported any problems so far... ?

[99-life]

Thank you for sharing your results even though it wasn't sucessful.

[Flynall]

Bonding aluminum-to-aluminum requires an aerospace grade procedure. Usually both parts are degreased, chemically etched and then alodine treated to convert the surface into a "bond friendly" surface by preventing further oxidation. The adhesive (usually a aluminum filled epoxy that is formulated to survive in the vibration and chemical environment of the bond area) must be very carefully chosen. Each type has a different application procedure, many require a post cure heat cycle to a temperature that greatly exceeds the expected operating temperature that the part will see in service..

Bottom line: It can be done, but to do it properly would require a true engineering effort. In the end, it would probably cost more than buying a Power Now at full retail...

Butt gluing aluminum plates in the intake manifold with JB weld is a recipe for damaged engine or worse.

There may be some examples out there in service that have functioned well for a while, but who knows how long they will last before the combination or vibration and fuel contamination breaks down the bond?

Is it worth the risk of your damaging your engine or worse the possibility of a stuck throttle at an inopportune time?

RH

[mondo137]

The jbweld didn't adhere to the surface of my carb and the plegnim that I tapered was too thin and disentergrated into my engine. For now stock is just fine for me, its a great bike and handles well in the single track. Maybe during the winter I will try again. Next time I will dremel grooves and slide the plate in. As well I will use a decent size piece of steel and maybe solder it on? But until then I am going to ride it and worry about mods later.

Tommorows Sunday ?

[emcdan]

It's been several months and some hard riding since I manufactured my "powernow". I've had the carb off two or three times since. Still looks great. I really studied what I wanted to do before I took action. Using a dremel to cut the inside of the carb only makes good sense for the 03' models. I used a very small amount of epoxy on the plate joints. Ideally, if the homemade powernows are done without any compounds, there is little or no risk of something coming off into the motor. I'm very confident in my homemade model. The intake side has "dog ears" to fit like a puzzle piece on the carb ventura and yes it is worth the extra bottom end boost...just ask AV.

[Trauma]

Do you have any pictures? What do you mean about "dogears" on the intake side? I had the plates of mine shaped perfectly with the sides of the venturi, but not grooved into it. Also, how did you dremmel a perfectly straight groove into the side? Did you put in more than one plate? Putting plates above or below the equator of the intake would be pretty hard to groove.

[yz007f]

I have used JB weld alot before with out any problems. But anyway I used JB weld on my power now, with no problems. I have been riding for 3 months twice a week with it holding good. Here's how I did mine, I still made slots in the bell but used the JB weld to shape it and give it a better hold.

Power Now

[MXOldtimer]

I pulled the airboot off to find all three plates flopping around in the intake bell

I was kinda concerned when I first saw your picture. Due to the "length" of the unsupported lightweight plates. I was concerned they would begin to vibrate & flap, kinda like a ribbon in the wind. Glad your engine survived.

[Trauma]

That does not look like a big problem with '02 and earlier models. The '03 does not have the removable piece like you show in your pics. You have to either carve into the metal body of the carb or try and do it like I did(which did not work) Most of the work supporting the plate in yours is metal to metal. Most of mine was the JB

[av]

yz007f - the tabs you've cut out for the plate used to glue to the back of the older venturi are going to cut into the rubber air boot when you clamp it down. If you look into the air boot, you'll see that it is designed to mate with a flat surface (i.e. the back of the venturi), then fit over the groove on the side of the venturi and clamped down appropriately. I did a similar cut for my avNow version 1.0, but have since changed the design for version 1.2 to have the tabs sink into the venturi in order to have the flat surface that the air boot requires to mate with.

Trauma - nobody is making the tripple plated avNow, so if you want more than 1 plate (i.e. not an original PowerNow), it's probably best if you cut those tiny slits at the back of your 03 venturi to hold the tabs of the plates such as I've done for version 1.2 of the avNow (see link in my sig below). If you decide to remove the plates in the future, these tiny slits will stay inside the air boot and will not change the original design/air flow of the 03 venturi.

[emcdan]

Trauma...cutting the slits in the 03' ventura is not that big of a risk. I used only 1 plate for the lower 1/3 of the carb. There are two "struts" at this area. I put a piece of tape on both sides of the ventura to the taper. I then scratched a straight line with an awl. I made my dremel stationary with a 1/16 bit. I laided the bit in the scatched area and on low rpms "lathed" a small trench. The aluminum here is very soft so it does'nt take much. Making the plate is easy to slide in the grooves. With a small grinder bit I shaved the plate to fit the taper of the carb bore very snuggly. Really it can be pushed into the grooves and never even glued. Making small tabs or "dogears" larger than the carb opening prevent any risk of the plate from being sucked in the motor. I grooved the tabs to catch on the carb. Taking your time to make sure it's a tight machined fit is really pretty easy. The only caution I can think of, is not to make your "groove cuts" are not too deep and tapering the boot side of the plate so it will pierce your rubber when putting the carb on.

Two or three plates are possible, but I chose to do the 1/3 divider plate. I can truely feel the low end boost. Its a great mod.