First Tracker Make Over

[jpdevol]

Specs from Factory OU-72 (750cc)
EXHAUST
TT racing 1 ¾” X 42” exhaust pipe
½ mile and mile racing 1 ¾” X 28 ½” exhaust pipe
Megaphone (for mile racing only) 1 ¾” opening with a tapered body that extends
for a length of 17 ¼”; at which point the
megaphone has a width of 3 ½” ; this is followed
by a 1” reverse cone angled so that the exhaust
exit opening has a diameter of 2 ½”.
The following information is current as of 9-11-76. For updates or any questions, contact Y.I.C.
Racing Department (714-522-9397).
LATEST HEAD (#4) AS OF 9-9-76 (C.R. AXTELL)

I'd reckon 1.5" to 1.65" be good for street use w/BS34's (they were running 36-38 Lectrons)

 

[halfmile]

Today I found the envelope with the AMA Flat Track decals that I lost (misplaced) 3 yrs ago and installed them.

 

[halfmile]

After I added the electronics box and the UNI filters and all the new wiring, the front seat mount bolt is now almost impossible to get to without removing the number plate, air filter and carb on the left side. I made some stainless alignment pins to replace the 1/4" seat mounting bolts and used some industrial strength Velcro. There is a spring KCVJMC bike show next weekend and I want to disconnect the battery at the show and this will make it a lot easier. After the show I`ll bolt the rear and leave the alignment pin in the front.

 

[Adamc]

After I added the electronics box and the UNI filters and all the new wiring, the front seat mount bolt is now almost impossible to get to without removing the number plate, air filter and carb on the left side. I made some stainless alignment pins to replace the 1/4" seat mounting bolts and used some industrial strength Velcro. There is a spring KCVJMC bike show next weekend and I want to disconnect the battery at the show and this will make it a lot easier. After the show I`ll bolt the rear and leave the alignment pin in the front.
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Such neat work.... Why can't I do that!

 

[halfmile]

I can`t believe I did this. Last pic in post # 103 of this thread shows a license plate mount installed with a open thread and regular hex nut right next to 2 other bolts with capped nylock nuts. Absolutely unacceptable in anybody`s book. Lucky I came to my senses before I showed up at the KCVJMC show on Sat.

 

[46th Georgia]

I can`t believe I did this. Last pic in post # 103 of this thread shows a license plate mount installed with a open thread and regular hex nut right next to 2 other bolts with capped nylock nuts. Absolutely unacceptable in anybody`s book. Lucky I came to my senses before I showed up at the KCVJMC show on Sat.
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And to think, I LOOKED up to you.

 

[halfmile]

I had not started the first tracker since the make over and 750 kit in Sept 2022. I drained the tank and carbs for the winter. I got some no alcohol premium fuel today, started the bike and it ran like s*+t. Lucky for me I`ve got the Jim Dent Technical Assistance Hot Line on speed dial. Gave him the symptoms, followed his diagnosis (clean R side carb) and it runs like a jet! Thanks Jim. In fact it ran so scary good I rode it around the block twice. Going to go from 43 tooth rear sprocket to a 45 and leave the 16 tooth on the front. The new clutch, brakes, and charging system all work great. I even found neutral without a light. The open unbaffled megaphone`s could be a lot louder in my opinion but oh well. Tomorrow I`ll warm it up good and retorque the head.

 

[Jim]

Glad you got it sorted. You said that's the one you're taking to the Independence VJMC gig?

 

[halfmile]

Yes. The KCVJMC show is Sat at the Donnell`s Motorsports parking lot. I plan on riding it from the trailer parking area all the way over to the lot where the show is held. About 100 feet (maybe less) if I remember right.

 

[46th Georgia]

Yes. The KCVJMC show is Sat at the Donnell`s Motorsports parking lot. I plan on riding it from the trailer parking area all the way over to the lot where the show is held. About 100 feet (maybe less) if I remember right.

If you're gonna' do that, make sure you top the tank off.

 

[halfmile]

Today I ordered 2 of the chrome Big Mouth reverse megaphones. NO BAFFLE. They have a 1 3/4" inlet which would be great if I could find a couple of 1 3/4" combo bends but the ones available are 45mm (1.772 OD) so it looks like I`ll use 1 5/8 OD. Using the stinky little split reducer supplied with the megaphone is out of the question but I`ll think of something.

 

[halfmile]

Major set back. The combo bends arrived from Speedway and when I compared them to the previous ones the radius was totally different. These were supposed to be a 3" centerline radius bend as were the original tubes I already had in the left over bin BUT the new bends are 2 1/4" radius giving a 4 1/2" tube centerline. The tube size went from 16ga to 18ga too. When I called Speedway I finally got ahold of a counter person that told me they changed vendors on their exhaust parts. He went out into the warehouse and measured one and "Nope", they are different. He had ran into this before and transferred my call to customer service who promptly refunded the charge to my credit card and told me not to bother to return the items and maybe I could find a use for them someday.
Now I`ll try Hooker or Headman as they offer the same type combo and J bends but at a higher price. "Bummer"

 

[46th Georgia]

Major set back. The combo bends arrived from Speedway and when I compared them to the previous ones the radius was totally different. These were supposed to be a 3" centerline radius bend as were the original tubes I already had in the left over bin BUT the new bends are 2 1/4" radius giving a 4 1/2" tube centerline. The tube size went from 16ga to 18ga too. When I called Speedway I finally got ahold of a counter person that told me they changed vendors on their exhaust parts. He went out into the warehouse and measured one and "Nope", they are different. He had ran into this before and transferred my call to customer service who promptly refunded the charge to my credit card and told me not to bother to return the items and maybe I could find a use for them someday.
Now I`ll try Hooker or Headman as they offer the same type combo and J bends but at a higher price. "Bummer"
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I am watching with great interest.

 

[halfmile]

I guess I`m the only one that payed any attention in HS metal shop. Today I explained to the sales person at Hooker what a centerline radius is. They don`t measure their bends that way. I did order 5 different 1 5/8" "J" bends because I remembered I have a welder, cutoff saw and a belt/disc sander. I`ll make this work. Spent a hour making this standoff to hang the muffler bracket from. Still needs cut to length.

 

[halfmile]

I made the rear megaphone mount using a piece of plexiglass so I could see where the slots in the megaphone mounts were then I transferred the pattern to a piece of aluminum. Changed my mind several times then threw it on the band saw and cut it out. Tomorrow I`ll finish the adjusting slots and detail and polish. If I only had some tubing bends.

 

[Mailman]

I made the rear megaphone mount using a piece of plexiglass so I could see where the slots in the megaphone mounts were then I transferred the pattern to a piece of aluminum. Changed my mind several times then threw it on the band saw and cut it out. Tomorrow I`ll finish the adjusting slots and detail and polish. If I only had some tubing bends.
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I am always impressed by your fabricating skills, nice work!

 

[halfmile]

Finished the bracket and mounted the megaphones in the approximate place I want them to be. Lots of room for adjustment. Now all I have to do is make the pipes and bends to match up with the megaphones. While I`m waiting on the tubing I`ll try to come up with a idea for a heat shield.

 

[Vincenthdfan]

Finished the bracket and mounted the megaphones in the approximate place I want them to be. Lots of room for adjustment. Now all I have to do is make the pipes and bends to match up with the megaphones. While I`m waiting on the tubing I`ll try to come up with a idea for a heat shield.

My goodness those are gonna have a bark to them...perfect.

 

[halfmile]

If there was ever a exhaust loudness enhancer, I`d buy several.

 

[Adamc]

Finished the bracket and mounted the megaphones in the approximate place I want them to be. Lots of room for adjustment. Now all I have to do is make the pipes and bends to match up with the megaphones. While I`m waiting on the tubing I`ll try to come up with a idea for a heat shield.

Nice job, well executed.