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Hi, Frustrated one, engine "BOG" is mainly caused by a rich air and lean fuel condition but it can also be caused by a lean air and rich fuel condition this situation rarely occurs and is only caused by the misinformed weekend warrior that owns a toolbox. If the bike has been sitting for months or years you will have to completely disassemble the carburetor and submerge the parts (except rubber parts) in "Carburetor Dip" It usually comes in a gallon bucket with a wire mesh basket that can be purchased at any automotive store. If it is not the above scenario then the following explanation will apply.
The more you open your throttle the more vacuum you are creating in your carburetor venturi and your intake manifold. When you are operating at higher RPM any unmetered air that leaks into your system can become more obvious.
Unmetered air is air that is getting into your system after the fuel has been delivered. If you have unmetered air getting into your system between the butterfly/slide of the carburetor and the cylinder head this will create a lean condition.
All of the rubber components of the fuel system like vacuum hoses and intake manifold that you mount the carburetor to are made of rubber. If none of these components have been changed they are more than likely highly degraded and probably cracked in places to allow unwanted-unmetered-contaminated air into the combustion chamber. Check all of your vacuum lines and vacuum plugs for carburetor synchronization. The vacuum plugs are in the head just after the rubber intake manifolds. The petcock has a vacuum line as well as part of the emission system.
1. Check the intake manifold for fissures.
2. Ensure the bands used to tighten the manifolds down on the intake are secure and have not bound up the manifold.
3. Make sure air box fittings are not warped and fit completely over the carburetor.
Your airbox is metering air and is the first step in a process of consuming air and fuel. The system requires the resistance of the air filter in order to get the proper vacuum to "SUCK" the fuel out of the float bowl and create the proper venturi effect.
Improper mounting and sealing of the airbox will create a small lean effect. This might seem like no big deal but you are inviting dust and debris in your engine that is doing slow damage by not having proper fitment. Fix it so you know it's not contributing to your issue. Pick the low-hanging fruit first.
Do not go and start adjusting anything at this point. It ran fine before. There is something wrong with the assembly or a component. Do not adjust your floats. Get it back to where it was. The moment you start tweaking everything is the moment you lose OEM settings which are a must-have for fine-tuning and maximum performance.
Fine-tuning your carburetor and multi carb syncing come at the very end following the proper procedure established by the Carburetor Gods.
For more information about your issue and valuable "FREE" downloads that you will need for viewing or printing please click on the blue links below. Good luck and have a wonderful day.
https://thumpertalk.com/forums/topic/786126-pw-80-help
https://www.youtube.com/watch?v=hLfN3jiTl1I
https://www.manualslib.com/manual/581567/Yamaha-Pw80-N.html
https://www.partsfish.com/page/oem-parts-for-yamaha
YAMAHA PW80 Owner Manual

2011 Yamaha PW80 | 159 views | 1 helpful votes


Hi, Richard and the usual suspects are:
1. Idle speed improperly adjusted.
2. Inlet system air leak.
3. Damaged or restricted fuel tank venting system.
4. Dirty or damaged air cleaner element.
5. The accelerator pump is inoperative.
6. Vacuum piston assembly malfunction.
7. The choke valve is not seated or leaking.
8. Restricted fuel supply tract.
9. Plugged bowl vent.
10. Loose or plugged fuel and air jets or passages.
11. Improper float level.
12. Worn or damaged needle or needle jet.
13. Loose or plugged main jets or passages.
For more information about your issue and valuable "FREE" downloads that you will need for viewing or printing please click on the blue links below. Good luck and have a wonderful day.
https://www.reddit.com/r/motorcycles/comments/3195bp/why_did_i_lose_power_with_my_new_exhaust
https://www.magnumtuning.com/en/detail/revolution-pro-motorcycle-speed-rev-limiter-cdi-box/yamaha/mt-125
https://www.magnumtuning.com/en/detail/dyno-boost-motorcycle-performance-chip/yamaha/mt-125
Yamaha YZF R125 Service Manual
https://www.partsfish.com/page/oem-parts-for-yamaha
https://www.manualslib.com/manual/1152232/Yamaha-Mt-125.html

Yamaha... | 174 views | 2 helpful votes


Basically, Yes! Almost all of the engine components(and most other things) are interchangeable, some of the first(oldest) models and some of the latest(newest) PW80's have some differences but as long as you stick to one that basically loks the same or around the same year as yours you should be fine, but most Engine Parts are the same! Don't forget you can take the factory installed "plug" out of the exhaust for more power if you want/need a little more!


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Yamaha... | 144 views | 1 helpful votes


Hi, Mark and the usual suspects are:
1. Severely discharged or a damaged battery should have 12.5 volts or more and be able to pass a proper "LOAD" test if necessary, you may have a cursory reading of 12.5 volts or more but little or zero amperage the battery is faulty and must be replaced, AGM batteries fail in this scenario more so than lead-acid batteries.
2. Check battery terminals for damage or corrosion, check the battery cables at "BOTH" ends for loose, corroded, or broken connectors, "INSIDE" and outside the cable harness, perform connector wiggle test and check cables with an ohmmeter if necessary.
3. Spark plugs in bad condition or partially fouled.
4. Spark plug cables in bad condition and leaking check for spark leakage in the dark
5. Spark plug gap too close or too wide.
6. Faulty ignition coil, module, and or sensor.
7. Loose, dirty, or corroded ignition module connector at crankcase.
8. Faulty CKP or CMP, MAP, ETS, ATS, TPS, O2 sensor.
9. Dirty air filter.
10. Intake air leak.
11. Water, dirt, or rust in the fuel system.
12. Carburetor contaminated, sticky float, plugged jets.
13. Carburetor has oil in the bowl due to excessive oil in pre-mix.
14. Carburetor vacuum diaphragm torn, cracked, not seated or installed improperly.
15. Multiple carburetors out of sync.
16. Fuel filter clogged.
17. Old or contaminated fuel.
18. Fuel tank vent system plugged or carb vent line closed off.
19. Gas cap diaphragm valve faulty.
20. Vacuum line from intake manifold to fuel valve is broken, cracked, pinched, or missing.
21. Carburetor controls misadjusted.
22. Incorrect valve timing.
23. Valve springs floating, weak, or broken.
24. Damaged intake or exhaust valve.
25. Incompatible performance parts.
26. The control module may be in "LIMP" mode
27. Check for engine trouble codes.
For more information about your issue and valuable "FREE" downloads that you will need for viewing or printing please click on the blue links below. Good luck and have a wonderful day.
https://yamahaclub.com/forums/topic/22496-xv535-misfiring
virago 535 loss of power
Yamaha XV 535 DX Virago Service Manual
https://www.partsfish.com/page/oem-parts-for-suzuki
http://mybikemanuals.com/suzuki

1995 Yamaha XV... | 84 views | 1 helpful votes


here's a website that has all this inform ation about all this and manuals everything totally free there are many actually but I personally like few .. let me know if u need help
thanks

Yamaha... | 205 views | 1 helpful votes


here's a website that has all this information about all this and manuals everything totally free there are many actually but I personally like few .. let me know if u need help
thanks

Yamaha Road Star... | 179 views | 0 helpful votes


Download RXV667 service manual
See P.139-144 initializing the amp.
reset. jpg-rkkbnsxso4sbwtwmk4jraix3-5-0_0.jpg

Yamaha Audio... | 171 views | 1 helpful votes


Sounds like a head gasket, worn valve gasket, as my first guess.

Yamaha Boating | 88 views | 0 helpful votes


keep it in a warm garage. use a short blast of starting fluid . add gas treatment to fuel in fuel tank keeps fuel free from water

Yamaha 2005... | 49 views | 0 helpful votes


There is a Pre Out. Use the FRONT terminals if your Bose are main front speakers.

image-pbwfvm3vgp5yadzogpz1bykh-1-0.jpg

Yamaha Audio... | 53 views | 1 helpful votes


Order the repair manual directly from Yamaha.

Yamaha Boating | 26 views | 0 helpful votes


Hi, Ron the answer to this question is way above my pay grade for this situation, I would call or visit my local dealer or reputable shop's service/parts department and inquire about any possible quick fix, answers, or parts inquiry.
For more information about your issue and valuable "FREE" downloads that you will need for viewing or printing please click on the blue links below. Good luck and have a wonderful day.
https://ourpastimes.com/identify-yamaha-its-engine-numbers-7517857.html
https://thumpertalk.com/forums/topic/1122349-help-decoding-my-engine-serial-number/
https://www.doityourself.com/stry/how-to-decode-motorcycle-engine-serial-numbers
http://oem-cycle.com/BikeIdentification.shtml

Yamaha... | 54 views | 1 helpful votes


Make sure there are no vacuum leaks on the engine manifold side of carburetor. There are 3 o 4 pieces on the engine side so inspect well.

If no leaks on engine manifold side then likely there's a blockage somewhere in the carburetor high speed circuit. Most economical solution is chinese knock-off for ~$20 US delivered.

If you can't find a cheap replacement then you'll need to do a deeper clean of carburetor by removing welch plugs and submerge in carb cleaner. You will need new welch plugs (kit) and likely kit will cost more than a knock-off carb.

Before tearing down carb, you could try Seafoam fuel treatment... probably less the 50:50 chance it will clear.

Yamaha Ef1000is... | 32 views | 1 helpful votes


https://www.amazon.com/Replacement-Remote-Control-DSPE492-VV486600/dp/B00HI0VIQU?_e_pi_=7%2CPAGE_ID10%2C7192052666

Yamaha Audio... | 34 views | 0 helpful votes


Maybe bass and treble settings OR the volume control IC has gone bad. Basically, all analog signals processed by DAC fed from DSP will enter this IC for bass and treble control. If it is bad, no bass and treble control can get. You should bear in mind that the setting of bass and treble is good before checking the volume control IC.

Yamaha RX-V992 | 50 views | 1 helpful votes


Sounds like you may have a problem with the float valve in your carberator. If it's stuck open, even when the engine isn't running gas could be building up in the carb because your carb float valve isn't limiting it. And if it's building up and filling the carb, then it will eventually drop into the engine and subsequent oil pan. Look for signs of excess wet gas in the airboxin. That's a sign something in the carb isn't regulating the gas right.

Yamaha 2004... | 32 views | 0 helpful votes


Yes it can. The rocker arm will hit everything on top of the head and it may drop a valve into the cylinder and smash the piston and under side of the head

Yamaha Cars &... | 25 views | 1 helpful votes

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