Power loss By motley (Read 1,676 times)

[motley]

First off; 2008, Vip Model, GY6, 10,000 ++ miles

Okay so for some time now I have been dealing with a major power loss, The Rpms hit at 5,000 then climb to 6,000, You might see 6,500 in time.

The scooter used to hit 8,000 rpms like it were nothing, Also as if it wanted to keep going, but I only red lined the scooter twice in it's life time 'at max 7,200 - 7,500'.


I have replaced the variator, New gates 18.1 belt, New rollers, a year ago I bypassed the petcock with a fuel switch, Brand new rollers, same weight, And a new stock clutch, after a decade of wear on the old clutch the pads were basically gone... lol. But I just bought another stock clutch for 20 dollars.

I converted to synthetic around the time my speed problems occurred, After doing a synthetic beak in the bike started running cleaner again 'seemed almost like new.
  
I know something is off about the bike definitely, Way before the bike messed up I could open the port from the intake going to the petcock and there would be back fire when letting off the throttle, There is no backfire. if anything you might hear a dododoodoo with a very very low rpm idle, to the extent of cutting off if you dont throttle it.

Just the other day I figured I would play with the primer while it was running, Oddly on center stand the rear wheel started taking off as if I engaged the throttle.

But two nights ago, I went for a gas station run late at night, the air was a little cool, Definitely remember being cold enough for a jacket, The scooter that night actually hit 7,200 rpms, at many points I stayed under the handle bars for better aerodynamics. 

My last thought is a valve adjustment, But no one in my area works on scooters, it's a 35 mile trip to any of them. And undoing the cover and doing it just scares me...

My mind is blown, When you read this, if something crossed your mind as to what could be the problem I would love to hear what you have to say.

[motley]

Update:

Was working on the carb today, Kids will be kids... Majority of all parts are lost... lol xD D:

Ordered a kit from a trusted seller

www.ebay.com/itm/Carb-Gy6-60cc-Carburetor-Scooter-Jet-Kit-Air-filter-50cc-49cc-19mm-PD19J-Taotao/172845188588?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649



^ Quick reference. Not a bad deal for 35 dollars honestly.

As soon as the Carb comes in I will react with an update as to how well the scooter runs, The same, Better, or worse.

[ucwt]

Don't be afraid to work on your garbage,
There are all kinds of how to videos and people here that will help if needed.

Think of it this way all that coin you save not paying someone to service can be spent on speed part....

Empower yourself!

[motley]

That's what I have honestly been trying to do.

Something about the thought of doing it yourself, Replacing the front fork, You ride down the rode hit a nasty bump and the entire front fork comes off. Sadly at the scooters age, Any mechanic tries interesting me into there new scooters...

I would prefer to be a part replacer if anything, Parts are really old.

It's weird, I thought the plastic on these bikes were dipped like helmets. Paint has been cracking lately, Mainly from direct sun.

But i do intend to get a 100 cc kit, I just want to ensure when the time comes I get the lightest kit, With the highest mm, Ive seen lower mm then they should be.

Or.. I want to look into the possibility of ordering a 150cc scooter and registering it as a 50cc scooter.... .. .

[ucwt]

I've always thought of it this way.
I would rather take that risk of me doing it myself than some dude I have no idea who or what he has been doing.

I don't want to die or get injured either but trusting my life to someone else's hand isn't something that has ever set well with me.

The bonus is it costs me a fraction of what someone else pays.

I am Leary with key components too but as you said its old so just riding it is a risk too right?

Just because they are a "scooter mechanic" doesn't necessarily mean it is better than you doing it. I wouldn't trust the local scooter guy with changing my oil because he and the other guy just happened to have the money buy some scooters and open a shop doesn't make him trained to assemble and service them but they do and are sketchy......

Be anal and check over everything, three time in some cases
But really trust in what you can do and learn it, will save you money and there is no price for self reliance.


Do the BBK I just put on a 52mm cylinder and piston in my 50cc and like it.

[motley]

So after buying the entire carburetor kit the scooter is very close to actually running better. Other than being told the scooter now sounds like a crop duster in the distance... lol.

Now I suspect a air fuel mixture issue, I will have to play with it a little more tomorrow to see if I can perfect it.

But now the scooter will instantly attempt to hit past 7,000 rpms on the center stand and it seriously wanted to keep going, no screaming to it either, and when actually riding it I only seen 6,300 rpms, Just 100 over than the original.

I obviously need more gas as when the scooter idles it slowly dies out, but a few throttle pumps will keep it running, I will attempt to prime it while it's running before taking it apart and adjusting the needle and jets. If it runs better, Than I need more gas. If it cuts out might need more air. Any of that right?

Or might still need more gas by adjusting the needle but play with the idle mixture screw and see what happens? No clue man xD

[ucwt]

Air fuel screw on the side of the carb will get you the idle you need. 2 and a half(ish) turns out is the standard so start there.

As for the needle you'll have to read the plug to see what it is needing under load.

[motley]

Yeah I tried 2 and a half turns for a stock setting and that still caused the idle to die down 'went bellow 1500'. Sorry I should of mentioned that, I stopped at three and a half turns and it still runs the exact same. Tried getting it at basically no turns and it was basically the same.

I suppose I could open it almost all the way to see what happens as a test, I also failed to mention I am temporarily using the new K&N style air filter, So there might be temporarily to much air going to the system for all I know, And it probably needs to be evened out.

I will disconnect the vacuum line off the intake as a test to see if it purrs.


As for the needle you'll have to read the plug to see what it is needing under load.

Dunno what you mean :/

Also in that kit I received some jets, ones a 85, 88, 90, Haven't researched them yet. I think the one I'm using is a 50 - 60cc basic jet setup. I know the scooter I have cant be a true 50cc as it would almost hit 50 mph sometimes, would take a little while lol

[motley]

Cant ride to work today, So somewhere around the top of the block 'more like around the cover' and the air filter when it idles down a little to low and cuts off I will see either vapor or smoke, cant figure out which it is, but it mainly comes out the air filter, And you might see a tiny spit of it at the block area at random when it dies off.

Dunno much about engines but maybe someone hear can help me with what I should try to do.
Any help is highly appreciated

---

Problem solved, Failed to consider that the new air filter was taking in way to much air..

---

I think the bike might have compression problems 

[ucwt]

Sorry man got busy yesterday but here is a picture of reading plugs.

www.turbododgeparts.com/assets/images/plug-problem-matrix.jpg

[ucwt]

Also I was having issues with my intake leaking so I put rtv around everything and solved my issue so give it a try but from the mileage you've stated I'm betting you need rings.

For 30ish bucks shipped I got a new 52mm cylinder, piston and gaskets off Amazon.

[motley]

Thank you for the info on the plugs !

Yeah I'm sure I need rings as well, possibly whatever is considered a rebuild. I noticed a lot of oil all over the engine, more like slime. My theory is the actual gaskets at the head, and that's where I might have my true 'power loss'. I just haven't had the time to take off all that plastic :/.

I will have to look into the kits, but my engine number is odd, mines a lb1p39qmb. So far qmb parts are interchangeable..
No clue what the L is for

[ucwt]

LB typically stands for Longbo brand engines.
It's a 139 qmb

www.amazon.com/gp/aw/d/B0747J7BLL/ref=mp_s_a_1_1?ie=UTF8&qid=1506827495&sr=8-1&pi=AC_SX236_SY340_FMwebp_QL65&keywords=52mm+big+bore+kit&dpPl=1&dpID=514ftvwUqXL&ref=plSrch

[motley]

I'm not going to lie, That's a really nice kit! Mainly because of the price. Is this the kit you ordered? If so what speeds are you averaging?

Also thank you for the information on Longbo, I read that somewhere, as well something about low. I figured maybe it was a low end model. But typically Vip model scooters always had better builds so dunno.

I easily have the money for it but I want to pay off some credit card debit first :/.

---

I don't entirely know that much about engines, But I don't have to replace something like a cam shaft with this? Some bearing or anything inside of the engine, lol?

Once again thank you!

[czmdiver]

Sept 30, 2017 19:06:44 GMT -6 motley said:

Thank you for the info on the plugs !

Yeah I'm sure I need rings as well, possibly whatever is considered a rebuild. I noticed a lot of oil all over the engine, more like slime. My theory is the actual gaskets at the head, and that's where I might have my true 'power loss'. I just haven't had the time to take off all that plastic :/.

I will have to look into the kits, but my engine number is odd, mines a lb1p39qmb. So far qmb parts are interchangeable..
No clue what the L is for

Slow down some.
First go get some Simple Green or Gunk and De-Grease the entire engine before taking anything apart.
Next go to the auto parts store and most will have tools to use for free and get a Compression tester to confirm your Motor is Clapped out.
To my knowledge you still haven't performed a Valve Lash check or adjustment, correct?
Really need to conquer simple tune up type work with success like your jetting and valve adjustments before your jumping into tearing the engine apart to install a BBK. 

If you do most likely you will end up with something that will Not run at all, many because of complete lack of experience miss the most basic of problems to overcome.
           Good luck.