Rocketa 150cc Only runs with STP Fuel Carb/Injector Cleaner By rocketapos (Read 1,582 times)

[rocketapos]

Scooter: 2006 Rocketa Cayman 150cc gy6 (1,600 known miles)

Speedo has been broken since I got it so have no idea how many real miles are on it. However from the tires it doesn't seem too many miles are on it on the factory tires.


Issue: The scooter will run perfectly for the first 2miles on a cold startup, then it will act like its not getting gas when accelerating from a stop light. However it will idle perfectly while the light is red.

When accelerating from a dead stop (only after its been driven for 7-10minutes; will not do this on a cold engine until 7-10minutes) it will almost like act like its not getting gas, wont accelerate, then will accelerate for a second or two, and it repeats itself for about 10seconds until it run (but still a little hesitate on full acceleration.

My work around: When I put in half a bottle of STP Fuel Carb/Injector Cleaner into a full gas take it will run perfectly without any of these issues. If I ever fill up with 91gas and don't put this into it, it will act up immediately!!!!!!

So something with this stuff is allowing it to run just fine, without it; it simply is un-driveable (people honking at me at lights when it turns green, road rage, etc)

Also, this is my only method of transportation for work and anything else. Without this scooter I'm facing a huge lost. Just need to find out why it is acting this way. I can ensure you this scooter has not been taken care of in the past, and due to limited funds currently I can't just start replacing parts here and there. (However I understand how important general maintenance is; when I had the funds & my truck, I was replacing my oil every 2k and replacing parts before they broke).

I was believing it could be ethanol buildup the first few times I put STP in the fuel, however since it doesn't run without it I am believe other issues are the cause. Maybe the STP is boosting the octane due to some mixture issue allowing it to run.








 

[rocketapos]

Let me add, that the scooter starts up like a clock, no issues there.

[Bashan]

First of all the "hi test" and premium gas concept is a load. I don't direct that at you, it's a common misconception. Premium gas is not better and actually has less energy per volume unit than regular. What it DOES have is ignition retardants that keep the gas from preigniting under high compression in performance engines. So the formulation allows the engine to "harvest" the energy that is available in the fuel. If you have a high compression engine and you don't run hi octane, you get preignition, or spark knock, and you not only waste energy but can damage your engine. Your engine is not even close to needing high octane, your compression ratio is probably about 9.25 to 1. To utilize the properties of high octane fuel you need a CR of at least 10 to 1. Hi test is just hi bucks and a waste for most scooters. My SYM does use high octane and a lot of other fi machines do too. My GY6s don't even come close. The octane has nothing to do with this.

Two things come to mind and the first is just a noodle that keeps noodling me. Loosen your gas cap and ride it and see if it's different, just to shut me up.

I think you're changing the mixture with the additive. Have you looked at the plug when it's running like crap? Don't do the additive and force it to run a while, maybe 15 minutes. Then pull the plug and see what it looks like. A pic would be nice so I can see it. I'm thinking your auto choke may have something to do with this. Have you pulled it and checked it? It runs OK for a short time and then falls in a heap. Either the auto choke shuts off and it runs worse because of it or it's not working and the bike is simply warming up.

I'm hoping Alley looks at this, he's great with this type of thing. Oh Alley, can you look at this guys problem if you're done checking on the baby? Rich

[Guitarman]

I'm thinking auto-enricher also. You might just have to adjust the air/fuel mix on your carb. The enricher feeds extra gas into the engine until it warms up. (5-10 mins) and then shuts off. If the carb is starving for gas, you will get the kind of problems you describe. That would be the first place I'd look. And just for kicks, run some seafoam thru it to clean the carb really well. Could be plugged. The STP SHOULD have cleaned the carb, but you never know...

[Alleyoop]

When was the last time the valves were adjusted, if they have not been adjusted I would adjust them both to .004 inchs. Make sure your air filter is clean and not restricting air to the motor. Then adjust the carb fuel mixture follow this procedure.
Alleyoop

scooterdoc.proboards.com/thread/1499/4ts-carb-tuning

If you want to check the ENRICHER that is easy. Before starting the motor take it off and lay it on its side where you can watch it. THEN cover the hole with your thumb and start the motor and keep your thumb on the hole for at least 3-5 mintues.
Now when you first take it off and lay it on it's side it should look like #1 pic:
As the your holding the thumb over the hole and the motor is warming up it should the plunger should start to EXTEND OUT and within 3-5 minutes it should be extended out about 1/4 of an inch pic #2.
Alleyoop

PIC #1:
RETRACTED COLD:


PIC #@:
EXTENDED WARM:

[rocketapos]

Thank you guys for replying back to my issue, I will look into the auto-enricher. I would of personally pulled the plug and replace it, however due to family issues I moved across the USA, and was unable to bring all my tools. Money is so tight I'm unable to even by a cheap china socket set to check my spark plug. I'm used to working on dirtbikes and cars/trucks. However I do not have the history of this scooter of what has been done to it (owner only had it a few months before selling it to me) and wasn't sure what has been changed. I personally never would of got a scooter without a history but with tight time/money and getting a job from moving I did not have the choice of getting something better. (Was only $500 bucks after all)

I've checked the air filter and its pretty much perfect. As for the seafoam, its almost ten bucks a can so I wont be able to do that now. However I feel you guys are 100% on the auto richer/choke.

I will state the scooter did run fine when I drove it 45minutes back from where I brought it. And ran fine for the next week. After that I let it set for about a month (really tight money/didn't have a job yet) and then once I found a job and started to ride the scooter this is when the issue began.

Is there a simply fix I could possibly try (I did bring my meter with me) to fix this? Such as simply removing the auto-choke and seeing if ethanol build-up is on this part. Let me state that scooters are brand new to me, and I don't fully understand how they are setup and work.

I use to be apart of a ford ranger forum, and personally understand how annoying newbies can be when it comes to these issues/understanding.

Let me note, I am fully aware of the octane and its affects on HC/LW engines. I just assumed that since the EPA tag on this scooter stated to use 90 or above octane that it was a HC engine. What would you guys suggest to use mid-grade or low-grade?

Again, thanks for the understanding of my issues, and for the help.

[Alleyoop]

If you do what i mentioned it just might do the trick. You already checked the filter so that is out, but now that you mentioned it has been sitting for a while the pilot jet and passage may be varnished up a little. So if you can get a can of carb cleaner they come with a thin straw, take the fuel bowl off the carb and stick the thin straw in the THREE HOLES you will see THE MAIN JET which is the ont sticking out the most then the next one down which is the PILOT JET and then another hole which is the OVERFLOW VENT. You just need to CLEAN out the PILOT JET and MAIN JET.
Alleyoop

[Bashan]

That octane label is based on Chinese gas and they have a different system for evaluating gas. It has no relevance to our gas so ignore it. It is all based on compression ratio, look yours up in your manual. Your bike should have come with a spark plug wrench. If not the universal wrenches are like 5 bucks. Rich

[Guitarman]

Since it's your only transportation, I won't give my usual advice which is to call a Preist and have it thoroughly cleansed of whatever chinese demon has taken residence in it.

SOooooo.....

Try what Alley said which is what I had in mind as well. When you let these things sit, they clog up pretty quickly. That's why I suggested the seafoam.

[rocketapos]

Thank you guys for helping me with this issue, however I would like to understand why this is happening, let me give you (from my very limited knowledge of scooters) my idea whats going on to see if its correct.

The auto-enricher gives extra fuel to the engine for the first few minutes (2miles for me it seems like) then closes up. And the reason why my scooter is acting up is because my jets are not providing enough fuel when the auto-enricher closes due to build-up.

However I still don't fully understand how STP will allow my engine to run just fine, and without it cause the above problems mention. Any insight as to way? I'm a person who doesn't want to just fix problems but rather understand them as well.

[Bashan]

These are what ifs, I'm not sure. What if it is set way too rich. What if STP thins the gas and leans it out. Auto choke keeps it rich to compensate for cold running and then shuts off the extra gas, then the thinned out gas is an adequate mixture. You might need to just readjust the mixture but first we need to get the actually mixture reading off of the plug without the STP.

[rocketapos]

So today on my day off, I was able to mess with the fuel/air ratio screw (keep in mind I only have a screw driver set which is why I haven't checked out stuff until I get my paycheck) and found out that changing it clockwise/counter-clockwise does nothing to the rpm like it should (either raise or lower it.

Any idea why it is not changing the rpm? I warmed up the motor for about 10minutes before messing with it.

[rocketapos]

Also checked to see if the gas cap is venting and it appear it is. No sucking sound when I open the cap after a full gas run.

[kz1000st]

You know, maybe I'm just a lazy schlub but I don't think the answer here is so hard. How much is STP injector cleaner, a couple of bucks. So use it and be happy it runs. You could try using less until it runs crappy then increase the dose. Family Dollar, Dollar General and numerous dollar stores stock their own brand for less. See if they work. It's not like it's Seafoam at $10.00 a can. Maybe eventually it will clean out what ever is clogging the thing and you can stop. What did someone's signature say?

"It was running fine until I fixed it"

[Alleyoop]

Jul 9, 2014 12:18:09 GMT -6 rocketapos said:

So today on my day off, I was able to mess with the fuel/air ratio screw (keep in mind I only have a screw driver set which is why I haven't checked out stuff until I get my paycheck) and found out that changing it clockwise/counter-clockwise does nothing to the rpm like it should (either raise or lower it.

Any idea why it is not changing the rpm? I warmed up the motor for about 10minutes before messing with it.

Pilot jet is clogged and is why it runs on your 2 mile trip then when the enricher cuts off the extra fuel it runs like snit. So get your dishpan hands and take off the carb and do what I mentioned with a carb cleaner and the thin straw works like a charm. When you turn the FUEL RATIO MIXTURE screw in either direction IT SHOULD EFFECT the way the motor runs(PERIOD).

Alleyoop