another 99 cc Predator build :)

[silverbear]

jb & Wayne,
Two questions for you guys. First, how essential do you think it is to have an upper mount of some kind? While I already figured on welding a small bracket to the cross bar on my frame (Schwinn straight bar), that will come later. With no upper attachment I've ridden with the new engine for maybe fifteen miles and have not noticed any tendency for the engine to twist while under torque... yet.

Second, what did you do about the exhaust manifold? While I intend to make up a welded exhaust this summer with an exhaust manifold which angles more straight out from the engine and less upwards and more quickly turns forward... for now I cut off the existing exhaust manifold at the most upwards point, attached a right angle copper water pipe coupling along with a straight section after it and to that attached the flexible exhaust pipe I had on the HS engine (which is no longer flexible). Each of these pieces got drilled where they overlap and a small sheet metal screw holds each section fast to the next. At the bottom end I used a hose coupling to hold it in place against the frame. Design is by Mickey Mouse, but works for now. What did you guys do?
SB

 

[wayne z]

My engine fits kinda tight between the downtube and the seattube. When I first got it installed there was less than 1/4" between the valve cover and the seattube. After about 10 miles use, everything bedded in and the motor moved back until the valve cover stopped it.
I used the BGF clamp on mount, and didn't trust it's rough fit to not let the engine move. I am running a belt drive to the rear wheel, belt has to be kinda tight, so there's already a lot of stress in the clamped engine mount. I added an adjustable front mount that has a short allthread for adjustment built into it.
For the exhaust, I cut the stock flange off the manifold pipe.
I cut the end off a threaded nipple,bored it for tight slip fit for 3/4 EMT.
I then attached the flange and screwed in the modified nipple.
I then bent a piece of EMT to my liking and installed it going foreward with a sweeping 180 below and to the rear.

I then took a piece of 2" aluminum tubing about 10" long and sawed in half lengthwise.
I used 2 EMT bolted clips on the EMT pipe to fasten the split tubing heat shield to.

 

[silverbear]

My engine fits kinda tight between the downtube and the seattube. When I first got it installed there was less than 1/4" between the valve cover and the seattube. After about 10 miles use, everything bedded in and the motor moved back until the valve cover stopped it.
I used the BGF clamp on mount, and didn't trust it's rough fit to not let the engine move. I am running a belt drive to the rear wheel, belt has to be kinda tight, so there's already a lot of stress in the clamped engine mount. I added an adjustable front mount that has a short allthread for adjustment built into it.
For the exhaust, I cut the stock flange off the manifold pipe.
I cut the end off a threaded nipple,bored it for tight slip fit for 3/4 EMT.
I then attached the flange and screwed in the modified nipple.
I then bent a piece of EMT to my liking and installed it going foreward with a sweeping 180 below and to the rear.

I then took a piece of 2" aluminum tubing about 10" long and sawed in half lengthwise.
I used 2 EMT bolted clips on the EMT pipe to fasten the split tubing heat shield to.
View attachment 45832

View attachment 45833

Wayne,
That's a very clean and good looking exhaust setup. Your pipe nipple arrangement would work perfectly for my purposes because I need to keep the exhaust manifold exit as low as possible since the bike is going to get an in frame gas tank... so every bit of space between the pipe and the gas tank is important. I also like your idea of using the emt clamps to hold the heat shield. Well done, sir!
SB

 

[wayne z]

Wayne,
That's a very clean and good looking exhaust setup. Your pipe nipple arrangement would work perfectly for my purposes because I need to keep the exhaust manifold exit as low as possible since the bike is going to get an in frame gas tank... so every bit of space between the pipe and the gas tank is important. I also like your idea of using the emt clamps to hold the heat shield. Well done, sir!
SB

I forgot to 'splain about the 90 deg fitting.
It is a 3/4 street ell. A regular 90 is too fat to fit 'tween the exhaust studs/nuts.
First I soaked it in muriatic acid/water about 50/50 a few hours to remove the galvenizing, followed by a good water rinse and a little soak in household ammonia to neutralise any residual acid.
I then cut some of the threadded end off to shorten it enough that it still had a little clearence with the end of the exhaust stud. I then bored the inside to match the hole in the flange, then welded them together.

 

[silverbear]

I forgot to 'splain about the 90 deg fitting.
It is a 3/4 street ell. A regular 90 is too fat to fit 'tween the exhaust studs/bolts.
First I soaked it in muriatic acid/water about 50/50 a few hours to remove the galvenizing, followed by a good water rinse and a little soak in household ammonia to neutralise any residual acid.
I then cut some of the threadded end off to shorten it enough that it had a little clearence with the end of the exhaust stud. I then bored the inside to match the hole in the flange, then welded them together.

Thanks for explaining.
SB

 

[andrewflores17]

thats a great looking exhaust as soon as im able to i may atempt something similar

almost forgot noise do you find it to loud i do with mine and may atempt some sort of muffler in the future

 

[silverbear]

Wayne,
I did a little looking on the net at conduit benders and see that there is thin wall conduit and rigid wall conduit, which I assume is thicker. What did you use?
SB

 

[silverbear]

Wayne,
I don't know if you've seen this thread y 2door, where he also uses 2/4" EMT conduit for his exhaust pipe and buffs it out to a shine almost like chrome. Further down the page he tells how.
http://motorbicycling.com/showthread.php?t=35675&page=3
Between the two of you I'm going to have a killer exhaust!
SB

 

[wayne z]

Wayne,
I did a little looking on the net at conduit benders and see that there is thin wall conduit and rigid wall conduit, which I assume is thicker. What did you use?
SB

Not sure but I think mine is thinwall. .045" wall thickness. The thickwall is used in more severe industrial applicatons, and is threaded just like water pipe.

Thinwall is easy to bend by hand with a hand (and foot) conduit bender. Called a "hickey" by electricians.

 

[jbcruisin]

Hi Silverbear, You asked some questions earlier. I only use a top rear mount because my motor mount pivots because it clamps on. On my tandem I have a motor mount welded to the frame. that one doesn't have a top mount & I've never had a problem. For my exhaust I cut the pipe like you did. Then I cut it at the flange & moved it about 90 degrees so it's facing forward & welded it again. You have to be careful that the front flange nut still clears. Then I use flex pipe. Wayne has a nice exhaust on his. I'm an electrician so I should bend one like he did..

 

[silverbear]

Thanks, Jay.
Now I'm on the lookout for a conduit pipe bender and figure on pretty much copying what Wayne did, but probably not until summer when the bike will get a kind of makeover. I was surprised to discover that with the Panther straight bar frame the predator engine fits in there better than the HS did. With the HS I had to cut off the top part of the choke lever in order to squeeze it in. With the predator the issue is more front to back room rather than height, so I have a bit of room to spare. The Predator has a nice, hearty sound to it.
SB

 

[wayne z]

Wayne,
I don't know if you've seen this thread y 2door, where he also uses 2/4" EMT conduit for his exhaust pipe and buffs it out to a shine almost like chrome. Further down the page he tells how.
http://motorbicycling.com/showthread.php?t=35675&page=3
Between the two of you I'm going to have a killer exhaust!
SB

After going to that thread, I tried polishing on mine with 00 steel wool, and it didn't take much elbow grease at all to get it polished. Havent tried yet, but i'm sure that if I followed up with some 0000, it would look nearly as good as the one in the other thread.

 

[wayne z]

Home depot, tru- Value ect. sells them. If you know any electricians, you could try to borrow one. Ya can't hurt it, they are almost as indestructabl as an anvil.

 

[silverbear]

After going to that thread, I tried polishing on mine with 00 steel wool, and it didn't take much elbow grease at all to get it polished. Havent tried yet, but i'm sure that if I followed up with some 0000, it would look nearly as good as the one in the other thread.

That's good to know. I can see that conduit has a place in my future. I plan to get a bender, probably next month.
SB

 

[chrisc]

I bought a couple of 49cc stickers from Cannonball . I bought them a few weeks back so he may have some left .
I recently installed a 99 cc predator on my jaguar replacing the 49cc HS . The difference in climbing hills is huge . I am using a Silent drive tranny instead of the Q-Matic and I love it . I removed the governor , drilled out the main jet ,and I am using the flex exhaust from Quenton with a custom manifold that I built . I am using a 2.5 " primary pulley , a 6" driven pulley , a 12 tooth output sprocket and a 50 tooth sprocket on the rear . My ratio is 10.37 and it pulls me great all the way up over 45MPH. I weigh 200 lbs and I am very satisfied with my set up .

Hi, wanted to know where you got the tranny and how much it was?

 

[tn97kouki]

The silent drive was Quentons first tranny . He has moved on to the q-matic . I found mine used from a forum member .

 

[flmotorbikes]

What is the cost of the engine

 

[killercanuck]

What is the cost of the engine

99 pred, Harbor Freight, do some research. Or read the whole thread(s), slacker.

 

[andrewflores17]

about a dollar a cc with coupon

 

[motor_bike_fanatic]

i dont see on the website where you need any coupon. its 99 on the website plus shipping.