mph issue
- Thread starter Randog707
- Start date
fall_down_stand_up
New Member
Im not big on the thin smooth tires....My bike handles alot better with the wider tires....The tread on my tires are were there is always tread on the ground so there is no bumping and I dont get flats anymore....With the smooth tread tires I was getting flats all the time....
My oppinion is the beachcruiser tires with light tread....No more flats....
John-John
Venice Motor Bikes
Custom Builder / Dealer/Los Angeles
It's sounds like your engine is 4-stroking... (it's a little too rich)
You should run about 4 gallons of gas through your engine before you start trying to tune it, because it will keep changing as it breaks in.
Also, if you're planning on modding your pipe or getting a expansion chamber, you should do that before tuning the carb!
Venice Motor Bikes
Custom Builder / Dealer/Los Angeles
Also, don't re-jet your carb until after you put on the new sprocket!!! (That changes the way the engine runs too!!) 
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captainrichhill
New Member
I had the same issues with my bike bogging down at the top end. I figured it was too rich because I would get on a long straight away and run at full throttle. As the fuel in the carb float bowl was consumed it leaned out the mixture and the motor accelerated about 3-4 mph then would die from too lean (out of gas). That's how I knew it was too rich. If you do that procedure and it doesn't accelerate before it dies then it might be too lean.
My $.02
My $.02
Bikeguy Joe
Godfather of Motorized Bicycles
The surging problems are from fuel starvation. If your engine is too rich and you go WOT and it starts surging, there is not enough fuel flow, AND it's too rich.
Fix the fuel flow issue before you start "modding" your engine.
A new air filter, or putting holes in the existing one will only allow more air in, it's not going to "fix" anything, except a slightly rich mixture.
Fix the fuel flow issue before you start "modding" your engine.
A new air filter, or putting holes in the existing one will only allow more air in, it's not going to "fix" anything, except a slightly rich mixture.
Venice Motor Bikes
Custom Builder / Dealer/Los Angeles
I've found on my bikes that the 'surging' is from the engine being very close to being the right mixture but a little too much on the rich side. it feels like the bike is bogging & then it will get a little 'crisp' burst of speed, then go back to bogging... re-jetting a little smaller has always fixed it.
This is also how I know when I have the jetting right, it will run real crisp & clean with just a small bit of 4-stroking. (the little bit of 4-stroking tells me that it's not too lean!!)
This is also how I know when I have the jetting right, it will run real crisp & clean with just a small bit of 4-stroking. (the little bit of 4-stroking tells me that it's not too lean!!)
Tim_B_172
New Member
CNS carb available here: GasBikeShop Motorized Bicycle Engine Kits | Addon - Racing Carburetor (5-2)
It costs more than spookey, but there it is. I seem to remember paying about $50 for mine from a different site, but I can't remember which one...
It costs more than spookey, but there it is. I seem to remember paying about $50 for mine from a different site, but I can't remember which one...
Bikeguy Joe
Godfather of Motorized Bicycles
Could it be possible that the smaller jet uses less fuel and allows the restricted fuel flow to "keep up", also allowing for the right mixture at the same time? (slightly too rich+restricted flow=surging) (smaller jetting+restricted flow=just right).
Tcams
New Member
I just went for a ride to test after i tried to port match my exhaust and intake and at WOT it seemed like it was "surging" as venice stated above. Im not positively sure but at WOT it would bogg down and right after pick up speed. How do I rejet a little smaller.
What else could be doing this??
Thanks
What else could be doing this??
Thanks
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Tcams
New Member
After working on my exhaust & intake manifold, waited a few hours and took it for a spin and it took a couple tries to start, with the choke on. When I got it started and gave it a lil rev it bogged down and then died. I started it up and adjusted the idle screw to where it sounded good.
When riding the motor just doesnt sound right and I dont know what to adjust. I checked the plug and cant tell if its to lean or what. Ive never touched the c-clip since I put the motor on. I looked at it and I cant tell what everyone means by moving it up or down a "Notch". Any suggestions???
When riding the motor just doesnt sound right and I dont know what to adjust. I checked the plug and cant tell if its to lean or what. Ive never touched the c-clip since I put the motor on. I looked at it and I cant tell what everyone means by moving it up or down a "Notch". Any suggestions???
Bikewithamotor
New Member
You might want to try mounting your engine a little tighter
Nashville Kat
Well-Known Member
TCAMS ZONIE:
I would advise consulting a local bike shop or two- my rims are alloy on a newer Micargi cruiser. The 26 x 2.25 were easily replaced by 26x 1.75. That's a gain of 1/2" in narrowness. But the new tires are smooth tread and weigh much less too. I was able to use the same tubes, ad the tires only ran $10 each- but then I've had a lot of experience changing bike tires through the years. Be carefull not to pinch the tubes if you do this!
The first thing you'll notice is how much easier the bike pedals even before firing up the motor. The motor notices the difference as well.
I also eventually put the 27 x 1 1/4" wheel on the front, which is even narrower still. But this usually will require another brake- a road brake with a sufficiently long reach, mounted through the center hole in the fork above the wheel. This brake is a Campagnolo road brake- I don't recommend because it took special boring of the center hole, and reaming of the sides of the brake to get enough reach.. The back one would not fit if I try to put a 27" wheel on the back, and I'd need a brake with a longer reach, because the center hole of the cruiser frame is drilled at an upwards angle for a fender, not a caliper brake- But the front brake really works much better than the original cantilever.
Recent photos and one from last summer, just after the first tire change-
I would advise consulting a local bike shop or two- my rims are alloy on a newer Micargi cruiser. The 26 x 2.25 were easily replaced by 26x 1.75. That's a gain of 1/2" in narrowness. But the new tires are smooth tread and weigh much less too. I was able to use the same tubes, ad the tires only ran $10 each- but then I've had a lot of experience changing bike tires through the years. Be carefull not to pinch the tubes if you do this!
The first thing you'll notice is how much easier the bike pedals even before firing up the motor. The motor notices the difference as well.
I also eventually put the 27 x 1 1/4" wheel on the front, which is even narrower still. But this usually will require another brake- a road brake with a sufficiently long reach, mounted through the center hole in the fork above the wheel. This brake is a Campagnolo road brake- I don't recommend because it took special boring of the center hole, and reaming of the sides of the brake to get enough reach.. The back one would not fit if I try to put a 27" wheel on the back, and I'd need a brake with a longer reach, because the center hole of the cruiser frame is drilled at an upwards angle for a fender, not a caliper brake- But the front brake really works much better than the original cantilever.
Recent photos and one from last summer, just after the first tire change-
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Venice Motor Bikes
Custom Builder / Dealer/Los Angeles
Sure, it's possible, but I really don't think it's a restricted fuel flow issue, because these carbs don't need that much gas flow; & if the flow was restricted at WOT, wouldn't it just keep getting leaner & leaner until the engine just shut down or burned up?
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fall_down_stand_up
New Member
Nashville Kat,I just dont agree on the skinny smooth tires becouse with the wider tires I have better handling and control,also a tire with semi tread(tread always on the road with no bumming)keeps me from getting flats....When I had smooth tires I was getting flats every week,sence I switched to a beachcruiser tire with semi tread I havent had a flat in 6 months....
John-John
bairdco
a guy who makes cool bikes
jeez, this threads all over the place...
venice and joe, my bike used to surge all the time, not bad enough that i cared, and almost always under load. i figured it was because it was too rich. from past experience with mikuni sidedrafts on 4cylinders, the car would "burble" from getting to much gas. it sounded like it was drowning.
applying that to my bike, after i built my candleholder velocity stack, the bike rarely 4 strokes at all. even up super steep hills. it'll slow down from the load, but it doesn't bog, 4stroke, or burble. just keeps on chugging.
every now and then it gets that little surge, but it'll power right through it. so what worked for me, was to make it breathe. i didn't lean it on the fuel, i just increased the air. my clip's at the second from the top notch. and it is (top notch, that is)
as for you other guys, skinnier tires have less rolling resistance, but not necessarily less traction (look at a road racer going around a corner at 50mph,) they're smoother and faster, on smooth and fast surfaces.
fatter tires cushion the bumps better, keep you upright at slower speeds, and provide better traction in harsher conditions.
off road "knobby" tread leads to a bumpier ride, giving more vibrations you'll most likely feel in the handlebars, and will ultimately be slower than a smoother tread, but work great if you go off road, or in sand and gravel.
for cruisers, a fat street tread is probably the best way to go. plus, it just looks right.
the best tire for wet leaves, oil, slimy gutters, and ice, are ones clean enough to not mess up your carpet when you're home watching tv during these conditions.
venice and joe, my bike used to surge all the time, not bad enough that i cared, and almost always under load. i figured it was because it was too rich. from past experience with mikuni sidedrafts on 4cylinders, the car would "burble" from getting to much gas. it sounded like it was drowning.
applying that to my bike, after i built my candleholder velocity stack, the bike rarely 4 strokes at all. even up super steep hills. it'll slow down from the load, but it doesn't bog, 4stroke, or burble. just keeps on chugging.
every now and then it gets that little surge, but it'll power right through it. so what worked for me, was to make it breathe. i didn't lean it on the fuel, i just increased the air. my clip's at the second from the top notch. and it is (top notch, that is
) as for you other guys, skinnier tires have less rolling resistance, but not necessarily less traction (look at a road racer going around a corner at 50mph,) they're smoother and faster, on smooth and fast surfaces.
fatter tires cushion the bumps better, keep you upright at slower speeds, and provide better traction in harsher conditions.
off road "knobby" tread leads to a bumpier ride, giving more vibrations you'll most likely feel in the handlebars, and will ultimately be slower than a smoother tread, but work great if you go off road, or in sand and gravel.
for cruisers, a fat street tread is probably the best way to go. plus, it just looks right.
the best tire for wet leaves, oil, slimy gutters, and ice, are ones clean enough to not mess up your carpet when you're home watching tv during these conditions.