My Roketa Fiji 150 6,000 Mile Notes and Comments

[scooterollie]

Swamp;
Good point. No question Kevlar is a tough fiber but is it really that necessary in a good quality belt? A number of years ago, there were kevlar brake pads and shoes marketed. I put a set on a motor home I had. Later pulled them off when reports of bonding agent failures began to surface. Replaced them with O.E. pads and shoes that did a better job of stopping the beast.

[earlwb]

Well as I see it kevlar may make the belt less prone to breaking. But when the stuff comes out of China, you can't trust them to actually put kevlar in the belt. So like Swampsniper stated it is the rubber formula that makes or breaks a belt. The problem is who do you trust anymore, I see online stores selling belts for $60 to $70 bucks and they may be plain junk, the same stuff that sells for $12.00 elsewhere. Too many Chinese compnaies lying about the quality of their belts. heck I don't even know for sure if the Gates belts are really good yet. They may be counterfeits.
The Bando belt held together but boy did it really stretch out longer by quite a bit.

[jusdoit]

Hey Earl;
I have read on our forum that somes guys have drilled 1/4 inch holes in the back of their mufflers...perhaps 10 or 12 holes...drilled holes thru the buffer behind the endcap. Would that make any significant difference in performance or just add more "noise" to the exhaust ??

Have a Good One..........just Bob in NC

[swampsniper]

More noise than anything, on an otherwise stock set up.

[earlwb]

Yes like swampsniper stated you get more exhaust noise.
Putting on a performance exhaust doesn't really gain anything if the intake air filter system is stock. You usually don't even have to change the jets with a high-perf exhaust system in that case. The OEM air intake is that restrictive. Now if you install a K&N performance air intake, then you will notice more power. But then you do have to change the jets as the engine needs more fuel to run.

The stock exhuast pipe is really small inside diameter, like about 3/4" of a inch. A 1" or 1.25" exhaust pipe is really needed before drilling out the stock muffler will help.

[jusdoit]

Hey Earl;
Hope all is well in the "Lonestar" state !! Appreciate your responses on my posts.
A while ago, I told you I installed some running lights (3) on rear of scoot. Last Saturday, I put a "Turn Signal Flasher" on those lights. Hit the road Tuesday & Wednesday for long rides on busy roads in my area with lots of traffic. To my surprise ( or maybe "wishful thinking") not one vehicle "Tailgated" me like they have the past 6 months. Hopefully, the "blinkers" are getting the attention of drivers behind me and they will not just "ride my butt" for miles on these two lane roads. Like your thoughts.
Have a Good One........just "Bob" in NC

[earlwb]

Cool, sounds pretty neat. Did you get any pics of it?

[jusdoit]

Hey Earl...Hope all is well in Hometown...
Can I wire in some auxilliary lites into the AC circuit off the magneto wiring Got three on back I wired directly to the battery with a push button switch....don't want to load that circuit any more if I can use the Magneto AC output for a few on front of Scoot. I'm kinda ignorant about the electrical outputs on my Scoot...
Looking forward............just "Bob" in NC

[earlwb]

I think that one could OK. it depends on how much power the extra lights draw and how much the headlights draw.
I'd go for the LED lights as they draw a lot less than the incandescent bulb lights.

Since my scooter has dual 18/18w headlights, I think I could probably run a extra tailight bulb or two OK. With LED's I could go hog wild, so to speak.
A incandescent tailight bulb can draw 5 amps or so with the brake light on.

I have been reluctant to try two 36/36w headlight bulbs.

I think we can run some extra lights that keep the extra power draw below running two 36w headlight bulbs. I just never tried to determine how much though. I don't think anyone has figured out what the power ratings are for the different alternators on these scooters.

[jusdoit]

Earl;
Magster blew headlight bulb 1st. month...(5 months ago) found type at Honda dealer in 35w only...has been OK with other original since ....25w. Both pretty bright at start-up so AC system seems good. Gonna start looking for some LEDs for the front of scoot. We have stores...AGRI SUPPLY & TRACTOR SUPPLY that have a good assortment of various lites. Saw an Amber "Beacon" lite that spins 360 like on wreckers...rural mailmen, etc. Considering one to mount on top of rear baggage rack on the scoot. If I do, I will mount a push-button switch on my left handle bar grip. Switch it on and off when I feel the need for such an "Attention-Getter".
Do you know where on our scoots the Magneto wire connects from off the engine area

Looking forward.....finally got "Cold" here in last 2 weeks.....just "Bob" in NC

[earlwb]

I haven't tried tracing it yet. But there are several wires coming off the alternator and timing sensor from the engine. it might be easier to trace the tailight bulb and splice into that wire. or headlight bulb wires.

I have been thinking a lot about a couple of 5w White LED units installed into something to server like fog lights on the front myself.
But you then need a AC to DC converter and a microcontroller to PWM the LED's and the LED's need a heatsink. Then you have to get the LED units and heatsink into something spiffy looking too.
The 5w LED's put out light about like a 12w incandescent halogen light bulb.

[schoei1]

I got LED lights today, but with no instructions for wiring. There are three wires: White, Black & Yellow, but I'm not sure what the yellow wire is designated for. Can the black and white wires be hooked directly to the battery, or will I need to buy a fuse?

[wildbill84]

I installed some l.e.d's to my scooter a month or so back, and although mine had only 2 wires i hooked mine directly to the battery and everything's been fine, I'm not an electrician though.

Schoei - are the led's you got for automotive applications, or accent type?
If they're automotive the 3rd wire may be explained as one of either brake lt., running lt, or power. Wish my rear led's had 3 wires, as of now I have to have 'em in either running mode or brake mode, I prefer brake mode since i don't make it a point to ride at night.


Since taking this picture ^ , I've spliced the rear l.e.d to my brake lights.

[earlwb]

Schoie1, the black wire is ground or common, of the other two wires, one is the regular light and the other one is the brake light. Unless they are for turnsignals, then one is for left and one is for the right. Yes you can hook them up directly, but prudence dictates putting in a inline fuse someplace for them. Since the regular running lights (headlights and tailights)aren't fused anyway it probably is a moot point.

[schoei1]

It's an MRP LED Air Filter

["Big Guy"]

Wow, if it's from China, who knows!

I'm an LED dealer and China has different wiring. Usually blue, red & yellow or green/yellow. The black and white confuses me and sounds English to me, or more like CDI wiring.

Remember, you're using 12v dc power, so connecting them wrong (with LEDs) will not hurt the micro-processor (if it even has one). I would first try the white and black as white-hot, black-ground and see if it works. If it does, than the 3rd wire is for parallel wiring into an existing light kit.

[earlwb]

LEDs in the air filter? Wow, what will they think of next?

[earlwb]

Well at about 5640 miles, my scooter engine has developed a odd intermttent anamolie.
It idles fine, and can idle for a long time, seveal minutes Ok. It runs down the road Ok too, even at WOT. But intermittently, not all the time, right after you have slowed down and stopped (like at a stop sign or stop light), and then you go to take off and give it the throttle, it'll start to stall die or miss just as you give it a little throttle just off of idle speed. If you are quick you can catch it blip the throttle a lttle and it catches and off you go, no problem, until it happens again. It also doesn't do ths until you have gone about 10-12 miles or so.
My first thought was the air mixture screw needs to be backed out maybe 1/4 a turn. But it runs good most of the time. It just does this odd stalling dying effect intermittently. When you are watching for it to happen it isn't doing it. It waits for you to think it cleared up, then it does it again.
Most unusual.
So maybe a spark plug? Maybe air mixture screw needs to go out slightly. Bad gas?, some debris in the main jet on the slide needle or something. Lots of things to check ot now.

[earlwb]

I thought I would throw in a bunch of photos about the Carbuerator on a GY6 engine based scooter. The stock OEM carb has a 24mm bore, the high performance carbs are usually of a 28mm to 30mm.

There are three main jets commonly used on the carb, the OEM main jet is typically a 108 sized jet (the hole down the inside bore diameter). Then there is the 120 and 140 sized jets as well. If you replace your air intake system (and don't replace the exhaust system), you'll need to put on the 120 jet. If you then replace your exhuast system with a high-perf unit, you may have to put on the 140 jet, but it depends on how good the new exhaust system is. You have to perform plug readings to confirm this part for your situation.



The float and fuel inlet valve's normal position. I should mention that on some carbs, the picot pin has a slight knurled end on the right side (left side if you have the carb upside down. So if the pin doesn't slide out easily, you will need to use a small pin or nail and a small hammer or wrench and tap the pin out about 1/8" to get the knurled part clear.


The carb float bowl parts.


Carb Main jet shown next to the emulsifier tube. Note that usually the jets on the OEM carbs are not marked either. So be very careful not to mix up your jets, as it isn't all that easy to measure the hole or bore down the inside of the jet. The emulsifier tube has little tiny holes on the sides to help aerate the fuel and make it atomize better so the engine runs better. Note that usually the main jet sort of looks like it is in one piece with the emulsifier tube, but it comes out separately. Use a decent wrench to hole the emulsifier tube when you unscrew or tighten in a jet.


Carb Low Speed Jet.


You need to check the bottom of the float bowl out for debris or dirt particles. The debris will collect in the recessed bottom portion here:


Carb Drain tube with remote drain plug screw.


The top of the carb has a cap covering the diaphram and slide.


The spring goes on top of the diaphram, and the cap keeps it down under tension on the diaphram. Note that there is a small rubber tab on the diaphram, make sure it aligns in the small groove for the tab on the carb body.


The needle is usually held place using a metal clip, there may or may not be a small screw locking it in place.

[Deleted]

Hey, earl, thanks for the pics. In the last pic, what's the drain screw for?

[simony]

adnansaleen

If you intend to lay the bike up for an extended period its good practice to drain the carb bowl to prevent the fuel going stale and forming a varnish lick coating inside the carb which can block the fine holes.

R

S

[earlwb]

Like simony stated it is for draining the carb bowl when you lay up the scooter for a extended period of time. You also use it to drain the carb when you intend on working on it too. Plus if you get some bad gasoline it makes it easier to drain the bad gas out of the carb too. But getting bad gas out of the fuel tank sucks as you have to pull a fuel line loose and drain the bad gas that way.

[Deleted]

oh ok, thanks.

[earlwb]

I forgot to mention, that I had solved my odd intermittent stalling problem that started to occur a while back. When I checked the spark plug, it was showing signs of the engine being too lean when running, thus I surmised it was running too lean and getting overheated, even when the temps are cold outside.

I did go through everything looking for other problems like intake leaks, etc.

So I pulled the carb and changed out the stock OEM 108 main jet for a 120 main jet. The engine runs a lot happier now, and I can pull 55mph on the flats without needing a hill to go down to get up over 50mph. it'll do 60mph if you get a downhill run at it now.

Anyway, As I understand the problem, is the engines comes from the factory adjusted to run on the hairy edge of being too lean to start with. But when winter comes around, the cold ambient air makes the engine lean out a little bit more, resulting in it being a shade too lean. So the engine actually runs too hot then.

I plan on opening up the air filter box tomorrow and pulling out the thin foam filter material to let the engine breathe a little better too. I think with the larger main jet, I won't need the extra Air restriction now.

Air Filter Unit opened Up:


Identifying the thin foam filter screens and the crank case vent cover. They used some RTV silicon adhesive to glue down the thin metal shield on the sides.


Identifying the crankcase vent and oil catcher holes:


Identifying the fuel tank carbon canister gasoline fumes recycler hole:

[earlwb]

Dang, I still have that irritating intermittent engine stalling effect just off of idle.
Looks like Saturday is going to be a nice day, so I'll be able to check it out again.
I am thinking the vaccum is getting weak at idle, causing the fuel to run low in the carb's float bowl, or the carb's fuel inlet valve isn't working right. I might have to swap out the carb and see what happens.

[earlwb]

Someone else was having a lot of trouble finding where the little connector on the automatic enrichener is. So I edited this pics to help him out, maybe someone else will have trouble so I added the pics to this thread too.

On my scooter the power cable from the automatic enrichener leads off to the right side and excess cable is folded up next to the CDI unit. The actual connector is located in a bundle of wires and cables behind the starter solenoid here as shown in the pics. You have to cut some zip ties to get the cables all loose so you can pull it out where you can access it for whatever reason. When done messing with it, you need to put in new zip ties to replace the ones you cut off.

[earlwb]

Boy that intermittent stalling effect just off of idle is a puzzler. I put in a new fuel inlet valve on the premise that it might be leaking a little, and I readjusted the low speed air/fuel mixture screw a bit.
I had gone through everything once again and didn't find anything obvious.
So I went for a 25 mile ride and the scooter worked perfectly, so i figured I had the problem solved.
Sure enough later this afternoon, I took off and it started stumbling again. it doesn't do it at every intersection, just the really busy ones with lots of cars are about.
What is really irritating is the engine will not behave like this at home. I let it idle for as long as ten minutes a couple of time and it ran fine when I goosed the throttle.

So I then decided to go ahead and mount a manual fuel shutoff valve and remove the vaccum valve and block off the vaccum line too. Years ago I had a problem on a Yamaha 650, when the weather got cooler, the engine would die on me about 10 miles down the road from home. I finally figured out that the vaccum petock would become sticky when cool causing it to not open thus the engine would run out of fuel suddenly. Anyway, I had a spare vaccum petock, so I pulled it out, thinking to replace the original one, but when I blew into the fuel nipples, air would blow out the other nipple, I tried both directions and decided it wasn't any good anyhow. Thus I decided to simply install a manual shutoff valve instead. The original vaccum valve only lets you blow air in the opposite direction to fuel flow, thus it behaves more like a one way valve.
I haven't tried the scooter on a long ride to see if that fixed the odd intermittent stumbling or dying off of idle.

So tomorrow I am going to bite the bullet and check the valve gaps. I hate doing it as I have to pull off a PAIR system exhaust tube and other junk that is in the way. So since I have to do that, I might was well disable the stupid PAIR system anyway. I'll need to fabricate a new metal plate to block off the exhaust opening there when I remove the tube. Then I'll reconfigure the vaccum lines to not go to the PAIR air intake cylinder.

[earlwb]

Sure enough the valves needed to be adjusted, the gaps was close to being 0.000.
But it turned out getting the valve cover off was pretty trivial after all, no hassles at all.
I only had to take off the four 8mm valve cover bolts and remove the two 10mm acorn nuts on the PAIR air tube leading to the exhaust port, and the valve cover slipped right off. I flipped it over and it sat on the floor board right next to the engine just right. I didn't have to take any tubes or lines loose either.

I need to wait a couple of hours for the RED High-Temp RTV silicon gasket sealer to cure good before I fire up the engine and see how it is working. If you use a gasket sealer, use it sparingly a little goes a long way and any excess squishes out and could clog up a oil passage or something.











And yes, I placed the manual fuel cutoff valve in about the same location as the vaccum operated cutoff valve.

[tortoise]

earlwb said:

If you use a gasket sealer, use it sparingly a little goes a long way and any excess squishes out and could clog up a oil passage or something.

"Ya do what ya gotta do" to stop/prevent oil leaks, but the downside to using RTV silicone sealer is dealing with the residue "the next time". It often takes a very volatile solvent like brake cleaner or starter fluid to remove this stuff. An alternative strategy is to remove the valve cover O-ring, place it on a piece of waxed paper, and apply ArmorAll to both sides with a foam brush to keep the rubber "pliable". This treatment is also suitable for the carb diaphragm.

Another no-residue high-temp "form-a-gasket" option is Teflon valve packing . . sold in hardware store plumbing departments.

[earlwb]

OoooH, I like the teflon valve packing technique. Thanks.
The next time I have to pull the valve cover, that is it for sure.
On my valve cover, I think the problem is they made the groove for the O-ring basket a little too deep. Thus after a while it starts to leak as the O-ring isn't being compressed well.
But since I had the tube of Red RTV for a couple of years now, what the heck, I might as well use it. I don't remember having any difficulty in removing the RTV residue in the past. Maybe it is a repressed memory or something.

I took my scooter for a ride this afternoon, and except for having to turn down the idle speed a little, it is working OK. I'll hold my judgement for a while until I have ridden it a couple of times to and from work. That pesky intermittent stumble effect just off of idle seems to get you when you least expect it.