recommended mods

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crazzywolfie

New Member
#1
#1
hi. new here and kind of new to mini bikes. i was wondering what mods people would recommend? i have got it to the point where it should be drivable. i fixed the side cover oil leak and cleaned the carb so that it would actually run and stay running. i think i have got to the point that it is ready for some mods. i was thinking about making up a exhaust of some sort to get the heat away from my leg. even with the heat shield in place it seems to get pretty warm. also what is the best jet to run in these things? i currently got the stock jet in it but i got a few left over from my snowblower when i was tuning the new engine i tossed on it. the plug usually looks pretty foul when i remove it. also i don't know if it might be part of the issue or not but when i did do a compression test it was only putting out about 75psi. it usually runs pretty good but i haven't really got to drive it. i also have no idea how long it had been sitting before i got it. the carb was pretty tough to thoroughly clean out and get the engine running right.
thanks CW
 

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BBQJOE

BBQJOE

Member
#2
#2
crazzywolfie said:
hi. new here and kind of new to mini bikes. i was wondering what mods people would recommend? i have got it to the point where it should be drivable. i fixed the side cover oil leak and cleaned the carb so that it would actually run and stay running. i think i have got to the point that it is ready for some mods. i was thinking about making up a exhaust of some sort to get the heat away from my leg. even with the heat shield in place it seems to get pretty warm. also what is the best jet to run in these things? i currently got the stock jet in it but i got a few left over from my snowblower when i was tuning the new engine i tossed on it. the plug usually looks pretty foul when i remove it. also i don't know if it might be part of the issue or not but when i did do a compression test it was only putting out about 75psi. it usually runs pretty good but i haven't really got to drive it. i also have no idea how long it had been sitting before i got it. the carb was pretty tough to thoroughly clean out and get the engine running right.
thanks CW
Click to expand...
I have a Baja as well.
So far, Mikuni carb, billet rod and flywheel, straight pipe, 18lb valve springs, mamba jr cam, torque converter, 60t rear sprocket, removed governer.
This thing moves and has lots of torque.
 
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crazzywolfie

New Member
#3
#3
i don't know if i would want to spend that much on this thing. i got it for free and don't see it being worth that much. which mikuni carb do you got and how is it compared to the stock carb? i was also thinking about playing with the gear ratio but i think i need to actually drive the thing a bit before making any decision. i have considered ordering a torque converter setup but still not really sure if i want to put too much money into this thing or not. i do got my 4x4 toy that i should probably be focusing on.
 
BBQJOE

BBQJOE

Member
#4
#4
crazzywolfie said:
i don't know if i would want to spend that much on this thing. i got it for free and don't see it being worth that much. which mikuni carb do you got and how is it compared to the stock carb? i was also thinking about playing with the gear ratio but i think i need to actually drive the thing a bit before making any decision. i have considered ordering a torque converter setup but still not really sure if i want to put too much money into this thing or not. i do got my 4x4 toy that i should probably be focusing on.
Click to expand...
If you're not into spending much, I'd get a $79 TC from chinabay, and remove the Gov properly.
You'll be just fine and happy.
 
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crazzywolfie

New Member
#5
#5
i am still a bit hesitant about ordering a TC setup for this thing just yet. even after taxes and shipping the cheapest TC setup is about $150 Canadian. it really would not take a whole to get into this thing more than it is worth especially since i have not even really got to drive it much yet. i have only taken it around the block after cleaning the carb.
 
neo71665

neo71665

Member
#6
#6
Just wait till you have a few rides under your belt, You will then be willing to spend more. Most likely tear it down, fix the little things, rebuild it better.
 
Raskin

Raskin

#8
#8
Well bare minimum clean out gas tank and replace hose to carb..I would get a new stock carb.. it will run way better if won't idle well.. if idles good leave it...drill some holes in stock air box for more air and put a header exhaust and silencer(if needed).new spark plug......mildly further..a high flow filter kit,rejet carb.....where you gonna ride it?if mostly off road with some small hills higher gears will just suck..if you gonna ride mostly flat dirt roads and some street you could bump gearing up a tad depending on how much low end torque you want to lose..this all on the cheap...cheers
 
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creia

creia

#9
#9
How about upgrading your BRAKE? A lot of talk about performance (read: speed) upgrades, which is all the more reason you need a good brake to STOP. If you bike is anything like the BAJA DBs we have had the brake is pretty crappy. We replaced them with the Promod hydro brakes- MUCH better.
Michael
 
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crazzywolfie

New Member
#10
#10
thanks. i have already gone through the fuel system and carb pretty thoroughly. it seamed like it was running pretty good. i will most likely end up playing with it off road and maybe the odd run to my bosses house and back. it is pretty hilly around here. what jet would probably work best in something like this. i haven't started messing with the jets yet. i still got a few left over from when i put a new motor on my snowblower and needed larger jet to keep it running happy.

the brakes seem like they are working good but i haven't inspected them yet. i am also guessing the Baja DB's also have disk brakes like on a bicycle. hydraulic are the better way to go with disk brakes. mechanical brake usually got to be kept pretty tight to keep them working decent where hydraulic brakes are pretty self adjusting for the most part.
 
Raskin

Raskin

#11
#11
You got a drum brake..like a Coleman ct200u...they are squeeky when cold....I like them..they stop good..better than stock db30 disc..downside is you got to take back tire off to service
 
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crazzywolfie

New Member
#12
#12
ya it has a drum brake. it don't look like it is that hard to take the bad rim off. i got to take the back rim off eventually to fix the back tire. it has a slow leak. it just sucks that pool season is over. it is a lot harder to find a slow leak when you can't just toss the tire right in the pool rim and all.
 
Raskin

Raskin

#13
#13
Just spray dishsoap in a spray bottle and look for bubbles..I never was a donut dunker haha..if it sat and was gone flat it probably need rim inside edge bead cleaned with a wire wheel on a drill and check that old rim valve stem might be a dry crack where meets rim..good time to get another..those cheap....then light sanding and cleaned... reseat tire on bead if no nail hole..and recheck after it sits a bit
 
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BBQJOE

BBQJOE

Member
#14
#14
My last school of thought:
If it runs alright, and you're not sure you're going to use it that much, just leave it alone and just enjoy it, the Baja's aren't bad all by themselves. Just back out the throttle screw.
 
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crazzywolfie

New Member
#15
#15
not everyone has a pool tho. it makes it easier to find a slow leak. it usually takes a couple days to slowly leak out. i haven't even looks to see if there is any nails in it or anything. i am pretty familiar with cleaning beads and changing valve stems but never worked on something so small. hopefully the beads on tiny tires are easier to break than larger tires. i was changing out my daily drivers spare tire today and reminded why i wouldn't mind a proper tire changer. old tires are a pain to deal with. new tires just slide on.

this mini baja is starting to get a bit annoying. it seemed like it was running perfect before i replaced the side cover gasket and now it is not running right. it seems to idle decent but stall with a backfire when decelerating. i am going to try cleaning the fuel system again. maybe all the rolling around while cleaning the engine knocked some crud free in the carb or fuel tank.
 
BBQJOE

BBQJOE

Member
#16
#16
crazzywolfie said:
not everyone has a pool tho. it makes it easier to find a slow leak. it usually takes a couple days to slowly leak out. i haven't even looks to see if there is any nails in it or anything. i am pretty familiar with cleaning beads and changing valve stems but never worked on something so small. hopefully the beads on tiny tires are easier to break than larger tires. i was changing out my daily drivers spare tire today and reminded why i wouldn't mind a proper tire changer. old tires are a pain to deal with. new tires just slide on.

this mini baja is starting to get a bit annoying. it seemed like it was running perfect before i replaced the side cover gasket and now it is not running right. it seems to idle decent but stall with a backfire when decelerating. i am going to try cleaning the fuel system again. maybe all the rolling around while cleaning the engine knocked some crud free in the carb or fuel tank.
Click to expand...
Of course everyone has to ask, and I will this time. You did make sure the marks on the cam and the cranked matched up, right?

Something I noticed the last time I had mine open, I got lazy and thought I'd just use some gasket pookie instead of making a gasket.
When I put the side cover on, the engine was hard to manipulate by hand.
Not that this even means anything, except the gasket is totally required.
 
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crazzywolfie

New Member
#17
#17
i didn't even look at the marks on the cam or crank since i wasn't touching any of that stuff. the crank seemed like it spun pretty good by hand. i might try pulling the clutch and spark plug and see how it spins. i thought it was spinning good.
 
Raskin

Raskin

#18
#18
That gearcase gasket also serves as a camshaft end play..too thin puts pressure on it since gearcase closer with no gasket.......those timing marks not aligned was my first thought also about backfire running issue..once you get this neglected little bike going will be fun..
 
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crazzywolfie

New Member
#19
#19
the timing marks are exactly where they should be. the engine spun the same with the cover off as it did with it on so i am pretty sure my gasket is fine. i think i might have found my issue. there was some crap in the fuel strainer cup but nothing in the float bowl so hopefully it will run good again.
 
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crazzywolfie

New Member
#20
#20
well fired it up today and it seems to be running ok but still seems like it is running pretty rich. the plug keeps getting fouled up quick. i also noticed when it stalls it won't fire back up without using the choke. what would cause this? i have read that drilling out the idle jet should help it run better on deceleration and backfire less. is that correct. also what main jet is usually best for these small engines. i am guessing the main jet must be too large if the plug is fouling up
 

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