Comet 30 on a Baja Warrior= AWESOME!

buckeye

buckeye

Well-Known Member
#62
#62
Wow, both of you have done a great job. Can't wait to put a header on mine. That makes a huge difference in the sound as well as the looks of the engine. Nice guys!
 
B

Bluethunder3320

New Member
#63
#63
joekd, that bike is sweet!

buckeye, thanks, and im not near done!

air filter and header (already have)------FREE

remove the governor-----FREE

18lb valve springs--------$8.00

Re-jet carbeurator--------$6.00

GX140 emulsion tube---$15.00?? really that expensive?

Index spark plug---------FREE (ill find washers and try it)

adjust spark gap to 0.045"----FREE

cut off every other cooling fin---(i want opinions on this)

Porting--------------FREE

gasket alignment------FREE


debating doing these:

billet rod--------------$60

flat top piston-------$23

.265" lift camshaft----$50

muniki 23mm carb-----$50

manifold----------------homemade?
 
B

Bluethunder3320

New Member
#65
#65
valve train upgrades are :censure: expensive. :shrug: i dont know. would it be that bad without?



air filter and header (already have)------FREE

remove the governor-----FREE

Index spark plug---------FREE (ill find washers and try it)

Porting--------------FREE

adjust spark gap to 0.045"----FREE

cut off every other cooling fin---(i want opinions on this) FREE

gasket alignment------FREE

18lb valve springs--------$6.00 on OldMiniBikes

Re-jet carbeurator--------$4.00 on OldMiniBikes

GX140 emulsion tube---$9.00 on OldMiniBikes

billet rod--------------$60 on OldMiniBikes

flat top piston-------$16.50 on OldMiniBikes

.265" lift camshaft----$50 on OldMiniBikes

TOTAL ABOUT $150
 
Last edited:
D

Dual-500

Member
#67
#67
Bluethunder3320 said:
valve train upgrades are :censure: expensive. :shrug: i dont know. would it be that bad without?

air filter and header (already have)------FREE

remove the governor-----FREE

Index spark plug---------FREE (ill find washers and try it)

Porting--------------FREE

adjust spark gap to 0.045"----FREE

cut off every other cooling fin---(i want opinions on this) FREE

gasket alignment------FREE

18lb valve springs--------$6.00 on OldMiniBikes

Re-jet carbeurator--------$4.00 on OldMiniBikes

GX140 emulsion tube---$9.00 on OldMiniBikes

billet rod--------------$60 on OldMiniBikes

flat top piston-------$16.50 on OldMiniBikes

.265" lift camshaft----$50 on OldMiniBikes

TOTAL ABOUT $150
Click to expand...
Bump the compression up. What gearing is on the bike? Final drive ratio from jackshaft to rear wheel.

I would guess, if you have stock 10/50 final ratio that my bike would outperform yours even after the engine work you specified to your was done.

Mine is a Puma 200 that has: Header, 3/4" canister muffler, 140 emulsion tube. What is has that yours does't have and is not specified is the head on mine has been milled 0.077" and gearing changed on the final drive to 10/72.

I don't mention this as a challenge or hating. But, I think the head work (bump up compression ratio) and gearing make the most difference and want you to know that so you can make it perform to optimum with the most bang for your buck. You can get a head from a 160 cc that I think will work and raise compression ratio up.

Let's see what some of the other guys think.
 
B

Bluethunder3320

New Member
#68
#68
Dual-500 said:
Bump the compression up. What gearing is on the bike? Final drive ratio from jackshaft to rear wheel.

I would guess, if you have stock 10/50 final ratio that my bike would outperform yours even after the engine work you specified to your was done.

Mine is a Puma 200 that has: Header, 3/4" canister muffler, 140 emulsion tube. What is has that yours does't have and is not specified is the head on mine has been milled 0.077" and gearing changed on the final drive to 10/72.

I don't mention this as a challenge or hating. But, I think the head work (bump up compression ratio) and gearing make the most difference and want you to know that so you can make it perform to optimum with the most bang for your buck. You can get a head from a 160 cc that I think will work and raise compression ratio up.

Let's see what some of the other guys think.
Click to expand...
i dont have acess to milling machines myself, but i do know someone who works at a machine shop. whats a good price for this? and what do i tell him to do?

a gx160 head is $60

my gearing is 9t on the driven, 50t rear, 19" tire. i was told my ratio goes from 15:1 to 5:1
 
D

Dual-500

Member
#69
#69
Bluethunder3320 said:
i dont have acess to milling machines myself, but i do know someone who works at a machine shop. whats a good price for this? and what do i tell him to do?

a gx160 head is $60

my gearing is 9t on the driven, 50t rear, 19" tire. i was told my ratio goes from 15:1 to 5:1
Click to expand...
Good on the 9T up front on the jackshaft. Still a little tall on gearing though, lower will increase both acclearation and top end both. Yes, the ratio you have will be about 5:1 when the TAV2 transitions to high. Here's a gear ratio chart I setup for the Puma that also has 19" tall tires.

Gear Ratios and RPM

For the head, this one may work, you will need to do some research on that. I believe I read the 160 head fits the 196 clones. Some of the other guys can tell you for sure.

I took 0.077" off of the head on the 196 cc clone that came stock on the Puma 200. I read somewhere a guy building a go-kart clone took 0.075" off of the head with a belt sander. Not suggesting you do this with a belt sander. Point is it's not real critical machine work. You should be able to take 0.075" off of it without any problems. That single change will probably yield the most bang-for-buck.

I would think the head will yield more results than the cam. Add the cam to the head work and it'll really wake it up. The head work to increase compression basically raises the whole torque upwards across the spectrum from idle to wide open. With the gearing you have on it and a TAV you won't over-rev it.

For machine work on the head. I don't know what would be a fair price for that work - I would guess certainly under $50.00. With the spare parts you have do you have a spare head? If so, PM me and let's discuss.

Here's a picture of the setup I used doing mine. I turned a flat aluminum plate from a piece of round stock that was laying around in the scrap bin and mounted the head to that and grabbed the mounting fixture in the lathe chuck.





Here's a picture of my bike showing both exhaust and the 72T rear sprocket. I added a support bracket to the exhaust the attached to the pipe just ahead of the coupling in front of the muffler and attaches to the cross bar under the seat.

 
Last edited:
B

Bluethunder3320

New Member
#71
#71
Oldschool said:
I think so.
But its your money, you decided to spend 150 dollars.
You can't build much of an engine on that budget.
Click to expand...
i havent bought anything yet. im gonna maybe just do some cheap things. maybe i can manage to mill the head myself somehow. also i have 2 spare camshafts. maybe ill do research on welding/grinding them
 
Last edited:
D

Dual-500

Member
#72
#72
You are off to a good start pricing and listing performance parts for your engine.

One thing I don't see here and forgot to mention in my last post is purpose. It's somewhat clear what the build purpoes is for the engine. Now, formulate the approace towards the objective. Seems, cost is also a factor.

You are building a clone for an offroad or trail bike that has 19" tall tires and a TAV2.

Your current gearing is 9/50 on the final or 5.55:1 for a overall ratio of ~5:1 when the TAV2 transitions to it's highest ration of ~0.90:1.

Have a look at the spreadsheet I included a few posts up. I would recommend not going above 40 mph for a top speed. For optimum performance, the bike should be geared to match the desired top speed with the top RPM you want to turn the engine - and build/tune the engine for that RPM range.

I have a guage set on my Puma 200 with a tachometer that I borrowed from one of my karts. Stock gearing of 10:1 with governor bypassed, it turned ~5400 RPM which is almost exactly 30 mph. Then I started tweaking it. Installed the TAV2 first, and in high transition it lugged the engine down to 3000 RPM with the stock final drive 10/50 or 5:1 which put the overall gear ratio at ~4.5:1. It ran ~37 mph with that setup.

Next thing I did was mill the head 0.077" and install the header, higher flowing muffler, and 140 emulsion tube. Stock jet in carb still runs the best. I also changed the rear sprocket from the stock 50T to a 72T. It ran better, much more acceleration and even better top end. Now it turns ~4800 RPM wide open and runs according to computations ~41 mph. Running a 10T on the jackshaft right now for 7.2:1 final ratio.

I have tried a 9T up front with the 72T rear and it accelerates a little better, but doesn't cruise as good - engine turns more RPM.

For your application, I would suggest a 5000 RPM engine build and setup the gearing to your top speed -vs- accelaration preference. If you put a aftermarket cam in it, be sure it matches the RPM range for the engine/gearing combination. Valve train modifications may also be necessary depending upon what your choice for the cam is.

Between head work to raise compression ratio and optimizing gearing would be the places you will find the most bang-for-buck performance enhancements.

Good luck with it. :thumbsup:
 
Last edited:
B

Bluethunder3320

New Member
#73
#73
wow, thank you! that is some really good info!

right now, the bike goes pretty dang well. however, i could use a little extra power. id like the engine to be able to reach its MAX RPM with the tav- 5000 sounds good to me :thumbsup:

tonight i will work on a silencer for the pipe i made. tomorrow, i hope to go on a nice long ride down at the tobacco fields with my friend who has a go kart.

his go kart is a manco, 15" tires. stock 6.5 clone but a 13.5 briggs muffler that i customized. 10T on clutch, 60T on axle. used to have a TC but heres the story-

his driver burnt out and its not saveable. so thats $90 he doesnt want to spend. he gave me the driven, backplate, and belt. i spent $90 on a driver and put the whole setup on my bike. then i gave him the centrifugal clutch that came off my bike and fixed up his kart, fixed the brakes, bypassed throttle setup, cleaned it all, and its working good.


going down the street FULL throttle i beat him on the low end, but he catches back up and our speeds are just about the same. and he gets stuck in a little mud, i blast through anything :laugh:


im going to update my list tonight. :thumbsup:
 
B

Bluethunder3320

New Member
#74
#74
no going riding tomorrow :sad:

i did finish the silencer though. just have to mount it tomorrow. i might not weld it to the pipe so that its removeable.

started as a paint can


drilled a 1" hole through the nozzle and bent it in with needle nose pliers


did the same on the bottom of the can


welded these pieces together so its long enough. came from a small bicycle frame


cut a bunch of holes in the pipe to make it like swiss cheese. then almost cut it in half towards the end, and stuck a washer in there and welded it, to prevent exhaust gasses from passing through the pipe and not enter the can.


then i inserted it into the can


here you can sort of see 2 small washers i welded on either end of the can to keep it from sliding around. to remove the can from the pipe, i have to angle grind off the washers. i could not weld directly onto the can because it is wayyy too thin.


i also fixed the headlight. when i had that bad crash, the light hit the pavement and bent it out of the rivots that hold it on..... so i took it off, took it apart, welded it, (it was hard because the metal is very thin) but i managed to get it done.


heres that spare head.






sorry for the millions of pics
 
B

Bluethunder3320

New Member
#76
#76
Dual-500 said:
Are you working in your dad's shop? Pretty creative fabricator for a youngster. :wink:
Click to expand...
nope its my shop :wink: and thanks!

parents let me take a room in the basement and set it up for a shop. even have a big electric duct for fumes.

just because im bored, i threw together a ton of pics of past projects. hopefully i didnt spam my thread too bad!

3 speed go kart, in progress
http://i924.photobucket.com/albums/ad86/bluethunder3320/100_1865.jpg

a frame i made that ill finish some day.
http://i924.photobucket.com/albums/ad86/bluethunder3320/photo-1450.jpg

this one never got too serious, because everything was too weak
http://i924.photobucket.com/albums/ad86/bluethunder3320/photo-1350.jpg

did lots of wheelies in this!
http://i924.photobucket.com/albums/ad86/bluethunder3320/IMG_4908.jpg

this one is funny, i stuck a little pocket bike motor into a small electric chopper. it needs a new cog for the pull start but it works still
http://i924.photobucket.com/albums/ad86/bluethunder3320/photo-2142.jpg

video of it
IMG_4592.mp4 video by bluethunder3320 - Photobucket

never went through on this with the 13.5hp and 5 speed, so its the frame im putting the 8hp and 3 speed into.
http://i924.photobucket.com/albums/ad86/bluethunder3320/photo-738.jpg

this is a point when i had that frame together i posted earlier
http://i924.photobucket.com/albums/ad86/bluethunder3320/photo-2476.jpg

i once had a 6hp flatty and 5 speed peerless in the go kart frame, it worked but it was slow. i could climb trees, no joke. i have a pic somewhere of it halfway up a tree
http://i924.photobucket.com/albums/ad86/bluethunder3320/photo-190.jpg

i made this intake, briggs carb on a tec! woo
http://i924.photobucket.com/albums/ad86/bluethunder3320/100_1719.jpg

early stages of the home made kart
http://i924.photobucket.com/albums/ad86/bluethunder3320/IMG_3391.jpg

a long time ago, i put a pocket bike motor on a electric scooter
http://i924.photobucket.com/albums/ad86/bluethunder3320/photo-146.jpg

it would have been awesome if i followed through on this...
http://i924.photobucket.com/albums/ad86/bluethunder3320/photo-138.jpg

heres a frame i built
http://i924.photobucket.com/albums/ad86/bluethunder3320/photo-116.jpg

this was absolutely nuts, built entirely from scrap metal, i actually rode it around the neighborhood almost every day for hours.
http://i924.photobucket.com/albums/ad86/bluethunder3320/photo-108.jpg

my ghetto-scrap bike next to the rigged scooter.
http://i924.photobucket.com/albums/ad86/bluethunder3320/100_1325.jpg

another pic of the scrap bike
http://i924.photobucket.com/albums/ad86/bluethunder3320/photo-74.jpg

sliced up this frame to fit a clone instead of the electric motor. worked for a while but i parted it out for the scrap bike
http://i924.photobucket.com/albums/ad86/bluethunder3320/photo-51.jpg
http://i924.photobucket.com/albums/ad86/bluethunder3320/DSCF5342.jpg

the first thing i ever hacked, that electric dirt bike with a chainsaw engine in it. yes it did work but it was slow
http://i924.photobucket.com/albums/ad86/bluethunder3320/oldwithchainsaw.png

i cannot believe this thing worked. a 3 wheeler out of scraps. it had decent acceleration and hit 25mph. only reason it pooped was because i had a all thread axle on bushings........they wore out :no: i am looking for a video of this, it was so unreal.
http://i924.photobucket.com/albums/ad86/bluethunder3320/photo-12.jpg

this was my experimental briggs (8hp). i got it running and messed with it. unfortunately one headbolt was rusted into the block, so it broke when i tried to take it out. i tried every method to remove it but everything failed, and the block is messed up now.
http://i924.photobucket.com/albums/ad86/bluethunder3320/photo-22.jpg

this is my tecumseh H60 that ive taken apart and put back together soo many times pretty much just for the heck of it.. i had it running but now it needs the carb back on
http://i924.photobucket.com/albums/ad86/bluethunder3320/photo-27.jpg

i have built way more things but im not gonna be going through pics all night :thumbsup:
 
Last edited:
B

Bluethunder3320

New Member
#78
#78
Dual-500 said:
You're dangerous! Remind me of someone I know all too well. :smile:
Click to expand...
im still alive but the worst thing i have is a lump of scar tissue on my right knee.

:shrug: maybe it wasnt the best idea to take the kart for a maiden voyage at 30mph with no brakes, no throttle, and no seat (i sat on the engine) well, the tie rod kinda, sorta, broke... and my leg went under the axle
 
You must log in or register to reply here.
Top