Exhaust kits for small engines

[augidog]

guys, what y'all got going on here is mostly way beyond me (i wish i had time to read more lately, glad i don't, busy in real-life) but i've been exploring the "mits" copies/replicas/whatevers...49cc X7 engines...and the info in this thread has been very helpful in that regards. with a self-imposed 50cc ceiling, i'm trying to push a gebe setup to it's limit, being willing to pedal to my limit in the bargain.

now, the only 2-stroke tweaking experience i have is bolt-on tanaka-branded components on stock crankcases & cylinders, but i know i can pass this advice along...

love your engine. break it in by the numbers. carburetor/intake tweak first, exhaust tweak after.

note the tanaka powerpipe includes a fitting to re-install the original muffler/catalyst after the silencer. i used it this way on my 32, and it looked funky but i could sneak up on deer at 35mph, and it had no effect on the pipe's pull at all. you could not hear it beyond a very light buzzing that changed tone with your speed...it was pretty sweet, actually

 

[Member 5549]

I Wonder

If you can sell those Augers on ebay...
after the engine is removed..
I bet there is someone out there that broke one !!!!
Might be able to get a few bucks out of it to make youre engine cheaper ...

 

[5-7HEAVEN]

Yep, Porkchop I misunderstood your post. Sorry.

 

[Porkchop]

Well, I ordered the friction drive kit today from Bikemotorparts.com I ordered the complete kit with both the 1" and 1.25" rollers, throttle and kill switch. I asked them about an exhaust kit. I was told they did not know of any and that was a commonly asked question that they got quite frequently. I was also told the engine I have, from the auger that Harbor Freight sells was a prettty good engine and they were really not very loud. I'll just wait and see. My kit should be here either Tuesday or Wednesday at the latest providing nothing bad happens. I can see a GP460 in the future though ! Now...if the GP will bolt on to my auger, man can I have some fun digging holes in the back yard ! Or better yet, maybe in the neighbors yard ! Ha ! Ha !

 

[Porkchop]

Yep, Porkchop I misunderstood your post. Sorry.

You owe me no apology. Thanks for all your replies and opinions !

 

[5-7HEAVEN]

Porkchop I also ordered the BMP kit and it arrived yesterday. It has the 1.25" roller, so my GP460 engine should buzz to over 12,000rpm at 40mph. Should take me awhile to get the bike running, unsure which one, probably my Raleigh 7-speed.

 

[Porkchop]

Porkchop I also ordered the BMP kit and it arrived yesterday. It has the 1.25" roller, so my GP460 engine should buzz to over 12,000rpm at 40mph. Should take me awhile to get the bike running, unsure which one, probably my Raleigh 7-speed.

I remember a post a few days ago where you said you ordered that kt. I'm starting to think you're the king of friction drives here. Ha ! Ha ! Do you have it installed yet ? I spoke with "James" when I ordered mine yesterday. He had never heard of the GP460. I gave hime the web site He said that was way to much power. Like I told him though, I have a car that will easily do 150 mph, but I don't max it out or floor it every time I take off from a stand still. I will admit though, I did get it to 135 once upon a time ! Hee ! Hee ! Anyway, what do you think of the kit's construction adn quality ? Just curious. Mine should be here Tuesday according to James. We're both on the right side, so it shouldn't take long. He said it was going out today priority mail.

 

[5-7HEAVEN]

Well I have front and rear Staton drives, an old Dimension Edge partial kit and this BMP. I also have plans to convert them to chain drive, using as much of the friction kit as possible.

Porkchop, the kit arrived yesterday. I was tired from work and a 15-mile trial ride from work to night school. (Can't get over it; it takes minimum 54 minutes to drive 10.5 miles in rush hour and 37 minutes by MB!)

Opened the kit at 4am. Postage was free which cost the vendor $13.50. I would've paid $56 shipping from another vendor.

Whomever packed the kit did an EXCELLENT job. I was impressed; one of the best packed box I've ever received. Lots of paper stuffing and the engine channel was wrapped separately in thin styrofoam sheet. Everything painted nice and neat, little stuff all bagged individually.

What I liked best was that the engine channel was machined to SLIP-FIT!!! the bearings! Yes! The shaft that holds the bearings is a pressfit with locking collars and roller with one-way bearing.

I didn't like the way the driveshaft protrudes into the clutch area. Unsure if it would contact the engine's clutch...so I decided to use Staton's roller, clutch drum and spacer with this BMP friction drive. That way I have more spindle options. BMP has 1", 1.25" and urethane 1.5" rollers. Staton has .875", 1", 1.125", 1.25", 1.375" and 1.5" rollers. Yes, differences in size does matter for engine performance.

BMP clutch drum and driveshaft have metric threads, whereas Staton is American. Not interchangeable for parts.

Staton uses a circular 1.25" engine spacer; BMP uses .875" long aluminum tubes as engine spacers. Staton's spacer is much stronger, but BMP's allows the clutch drum to travel .375" deeper for more clutch contact. According to the wear on the used clutch drum, Staton has .5625" clutch depth while BMP should have .875" depth.

That's a 56% difference in clutch surface!

Staton's clutch area could be improved by machining its clutch spacer.

Since BMP's driveshaft is .5" diameter, they use different-size ID bearings than Staton. The bearings I bought on ebay don't use snap rings. I'll need to get the ones w/snap rings especially since they're a slip-fit in the engine channel.

There is only one hole to position the rear struts on the engine channel. Unsure if that's gonna be a problem for me.

Without even assembling it yet, the kit impressive me with its top-notch quality.

 

[5-7HEAVEN]

Having trouble with the Staton clutch spacer I'm using with the BMP kit. It's a fraction of an inch too wide, not allowing the engine's four mounting bolts to thread in. Spacer needs to be clearanced where they interfere with engine bolts.

This is not a BMP kit problem. You won't have this trouble when you use their aluminum tubes as engine spacers.

LATEST UPDATE; Well, a few minutes of filing the spacer alongside the bolts cured the problem. I can now hand-tighten all four bolts very easily without wiggling, loosening and unloosening. I can hand-tighten until all bolts bottom out.

 

[fetor56]

5-7HEAVEN
"Unsure if that's gonna be a problem for me"....it was a concern for me so a fabbed two 2mm stainless steel brackets,so the struts now bolt in 2 places.