what did you do to your motorized bicycle today?
- Thread starter Skarrd
- Start date
It was a nice day here today, I put another 30 miles on my bike. Good ride.
Yesterday I ordered a higher compression head from DAX, along with some various other parts. Looking forward to seeing what kind of a difference it makes.
When I put it on, I am thinking about pulling the piston and cutting up the skirt to eliminate the intake interference.
Yesterday I ordered a higher compression head from DAX, along with some various other parts. Looking forward to seeing what kind of a difference it makes.
When I put it on, I am thinking about pulling the piston and cutting up the skirt to eliminate the intake interference.
I did the piston skirt trim on one of my engines, what I did was remove the intake and use a sharpie to mark the piston where it needed to be trimmed. 2 door gave me some tips on what to do, don't remove more than you need to and don't trim the exhaust side. Removing too much will affect the balance of the crankshaft system.
i do this to all my motors !
well about that loss of power and 1/2 throttle bog.... well i drained all the gas and reamed out the main jet to a .74mm and made shure there was no air leaks, then added high oct fuel mixed 50:1 and fired it up and the same problem ! didnt fix it !
just for kiks i swapped back to my old brigs filter and baaaam !!!! bike runs beautiful and will rev till it blows ! speeds up to 40mph !!!
what the heck ? is the sbp 90 deg filter restrictiing air flow and bogging my motor ?
or is it flowing too much air and making me run lean causing the bogging ??
ether way when i put that sbp filter on it bogs down like someone cut off the fuel air once i pass half throtttle !
put the old oversized brigs filter on and wow !!! it ripps now with the new .74mm jet size !!! even more power than before !!!!!
whats up here ? i thought this was supposed to be a performance filter yet my retro fitted brigs and straton air filter makes runs perfect and the sbp filter kills the performance ?
this bugs me as i have been around the block trying to find the problem here
checking for air leaks, rebuilding the carb, rejetting, draining gass, checking fuel flow, cleanning carb out, exe.... only to find out after a quick swap back to my old filter, its the new sbp filter itself thats causing the bogging issue !!!!
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There is a very simple way to tell if the sbp filter is causing a lean condition or a rich condition on your engine...... just run it down the road with no filter at all and if it bogs then you know you still need to go up on the main jet, if it runs great then you know the briggs filter is flowing more air to engine, the cloth filters flow better than a paper filter and for them to actually filter the dirt and dust out they need to be sprayed with filter oil.
Map
ok, so tune it with short runs and no filter !
i dont know why i didnt think of this, it cant flow any less restrictive than no filter, and if it bogs down with no filter than i am running too small of a main jet for my port job and carb size.... this also means that the paper filter that makes it work, is restricting air flow enough to make the too small main jet run correct fuel air ratio's.
but if it runs fine with no filter, well then i guess the bike is tunned correctly and the brigs oversized filter is not restricting it, and this would also mean that the small SBP filter is restrictive for a heavily ported china girl with a large carb.
i will put this to the test tomorrow, i hope the main jet is too small LOL this way i know i did not waste my money and going to the free flowing filter and a larger jet would result in more power !
as of right now with a .74mm main and the orange brigs filter and a 16mm carb and 16mm bore extended long intake, i just made a top speed run and broke my old grubee gt5's record ! this dax motor is turnning into a beast ! i pushed past the fastest speed i achived on my last motor and did it with less vibration and i felt some power left to spare but i pulled back on the throttle cause this motor just barley pased its break in period ! if i can get more air and fuel into her with larger main and a free flowing filter than i will be very happy !
i love the look on peoples faces when i blow past a moped on my bicycle !!!
Absolutely nothing because I just picked up this 1972 Yamaha RT2 360 with 234 miles on it and I've been working to get it on the road. It's been sitting for over a year and had a pound of rust in the fuel tank, the petcock was clogged as was the carb. All are clean now and as soon as a couple of parts come in I will put her on the road. As soon as that project is completed, I'll be back on my motorized bicycle to add some chain guards and install new brake levers with built in switches for my brake light. Happy New Year all you two wheel enthusiasts/motorized bicycle riders!!!!
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Riding NorCal woods OHV area, I had lots of interested lookers at my OHV motor bike.
I was not expecting the California OHV Association officials in two white cars with many antennas driving up and also asking questions.
I found the 21:1 ratio fine for trail riding and the swapped in fork with shocks also helped do way better this time. I can see if my GPS distance traveled on a tank that was not emptied got good MPG. Fastest speed with 21:1 I will need to connect to computer as I had not used the GPS in a while and did not find how to reset fastest speed, though it is in the raw data I can download to my PC.
MT
I was not expecting the California OHV Association officials in two white cars with many antennas driving up and also asking questions.
I found the 21:1 ratio fine for trail riding and the swapped in fork with shocks also helped do way better this time. I can see if my GPS distance traveled on a tank that was not emptied got good MPG. Fastest speed with 21:1 I will need to connect to computer as I had not used the GPS in a while and did not find how to reset fastest speed, though it is in the raw data I can download to my PC.
MT
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Made my own tensioner. Seems to work.
The one that comes with all kits is a POS, but everyone already knows that. It does not matter if you screw the bracket to the frame or not, the fact is the bracket and the steel that it is made of are made in a Chinese prison...you can't reinforce bad quality and design. If you have a "stock" tensioner eventually it will fly into your spokes, hopefully you are going slow when it happens...
I made it using 2 "U" clamps, bolts and some pre-cut steel from Home Depot. Takes some tinkering to get the chain alignment just right, but this one will not fly into your spokes.
Email me at [email protected] and I will email you a pic...I can't get it to upload here....it is worth trying, I made one for each of my bikes and after about 100 miles each they both work and are cheap and easy to make!
The one that comes with all kits is a POS, but everyone already knows that. It does not matter if you screw the bracket to the frame or not, the fact is the bracket and the steel that it is made of are made in a Chinese prison...you can't reinforce bad quality and design. If you have a "stock" tensioner eventually it will fly into your spokes, hopefully you are going slow when it happens...
I made it using 2 "U" clamps, bolts and some pre-cut steel from Home Depot. Takes some tinkering to get the chain alignment just right, but this one will not fly into your spokes.
Email me at [email protected] and I will email you a pic...I can't get it to upload here....it is worth trying, I made one for each of my bikes and after about 100 miles each they both work and are cheap and easy to make!
Beautiful bike!
I had one of it's smaller cousins from the same year...a 1972 DT100.
Rode the wheels off that super tough little bike! It was my very first new motorcycle and I abused it for almost a decade before it finally broke a coil.
Hope you have as much fun on it as I did on my DT!
Got my two brake levers in the mail, they sent me two left levers instead of a right and a left. Of course, the vendor said send it back and we'll replace it. Paying shipping twice is no treat, especially since many vendors gouge on shipping prices to begin with. Anyway, installed the one left one and hooked up the wires to my custom made LED brake light and I'm happy to report it works like it's suppose to. The levers are pretty much crap compared to the Tektros I took off, but they have a built in brake switch and a long sheathed wiring harness so it was pretty much a plug and play as far as the wiring.. I did swap out the two finger levers on the new assembly for the full hand levers from the Tektros for more stopping power. My hand made wiring coil easily handles the LED headlight, LED tail light and the new brake light. As soon as I get the right lever assembly in, I'll wire it into the circuit, so that either brake will activate the brake light. It's nice to have a motorized bicycle that's set up like a factory bike with all necessary safety features.
It's 10* outside with the wind a'howl'n. Supposed to get up into the 40's later this week -- may mess with the carb jets that I just received. No hurry, cause it's too darn cold out there to mess with it! Not worth the effort to warm up the garage, in my opinion.....
Yesterday, i introduced a friend to the motorized bicycle. 
He had seen it once before when he came over to hang out and work on one of his cruiser bikes, but it was not running then because of a bad magneto.
I got it warmed up for him and let him take it for a spin. He thought it was pretty sweet.
I would like to have someone to ride with here, and I have an old cruiser that I don't have time or money to build, but would like to see it built, so I told him I'd give him the bike if he wanted to motorize it, and would help him with the install.
I think he is going to go for it!
I got my new DAX high compression head in, and I want to do some proper port work and cut the piston skirt up a little to pull a little more out of it.
He had seen it once before when he came over to hang out and work on one of his cruiser bikes, but it was not running then because of a bad magneto.
I got it warmed up for him and let him take it for a spin. He thought it was pretty sweet.
I would like to have someone to ride with here, and I have an old cruiser that I don't have time or money to build, but would like to see it built, so I told him I'd give him the bike if he wanted to motorize it, and would help him with the install.
I think he is going to go for it!
I got my new DAX high compression head in, and I want to do some proper port work and cut the piston skirt up a little to pull a little more out of it.
The new brake levers I purchased from a scooter supply house are so stiff the brakes would not return and disengage the brake switch. I installed return springs on the arm of my disc brake calipers and the problem was solved. Maybe it would help if I lube the cables and the levers to minimize resistence. Now I have a LED brake light activated by both brake levers.
Keeping cables lubed is always a good idea. Even light surface rust on the surface of the cable will make it drag and in damp weather that can happen very quickly.