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5

A shop manual (particularly one with colour photos) will offer some spark plug diagrams / photos, to compare against your plugs, but they're not particularly useful. As you said, claims are contradictory. The problem is, that a symptom of too lean/too rich is that it doesn't run as well as it should. That's both ways. So a too-lean symptom for one person is ...


5

The secondary venturi act as a second carburetor when there is a demand for more fuel. When an engine is designed the carb must be large enough to flow enough fuel and air for the entire RPM range. A single barrel (venturi) carb large enough for the higher RPM range may flow inefficiently at low RPM. A carb small enough to flow efficiently at low RPM may run ...


4

Don't worry, you're not the only one who had to endure this pain... I had an old KZ650 I pulled the carbs from what it looks like a similar design. Like yours, it was older and the plastic air intake tubes were very stiff. Here is what I had to do. Pull gas tank off and disconnect from carbs. Pull the seat off to access the air filter and air box. Pull ...


4

You said that it is leaking from somewhere "under the tank" and then jump directly to the carbs. If it is the carbs, you'll probably have to tear into them. If it is from under the tank, there are a few things you can check: Is the tank intact? You may have rust burrowing through the tank and causing leaks. This is bad. Should be visible in the fuel ...


4

A carburetor is a carburetor: it doesn't matter what kind it is - it allows air to flow through it and meters the fuel to produce the optimal air/fuel ratio to allow the engine to run. That said, you'll have two things to look at: First, fitment. Will a different carburetor physically fit within the confines of the current carb? Will the carb output size ...


4

I need to get a carb kit and just haven't gotten around to it. A carb kit for a 1975 Honda may be harder to find than you think. You'd better start searching for that now or maybe even a used carburetor, if you can find one. My guess is the obvious one: Something did not seal when you worked on your carburetor. Pull it apart again. You missed ...


4

I'm not an expert on bike carbs, but if they are the same as car ones there will be two settings - one for mixture and one for idle. Once you have them balanced, you'll need to adjust these to get the right levels, while still keeping the pair balanced (i.e. increase the idle on both by the same amount, then check the balance, then decrease the mixture a ...


4

An air screw on a Keihin PWL26 only effects the idle circuit of the carburetor. The idle circuit pulls through the pilot jet exclusively. The pilot jet typically can deliver no more than 15% of the overall fuel when the throttle is wide open. The claim of 15% is based upon the inside diameter of the pilot jet and the inside diameter of the main jet. The ...


4

Gasoline sitting for two years in the float bowl of a carburetor will surely lead to some varnish. The hydrocarbons evaporate from the fuel and oxygen acts as an oxidation catalyst changing the remaining components into other compounds leaving varnish in their wake. Varnish will coat and clog the inside of the carburetor. Float bowl, floats, needle and ...


4

Depending on the application, there are lots of options for changing over to EFI from carburetor. Your best bet, especially if you're not a professional, is to find a system which is plug-n-play. Trying to find one which is compatible by retrofitting it from another vehicle would not only prove difficult, but would be very frustrating when it comes time to ...


3

If by "spark plug was dirty" you mean "black and sooty" then you're running rich and need to either lean out your mixture or double-check your air cleaner and make sure it's good. I know my old 73 CL125 would occasionally accumulate an impressive amount of dead leaves and pine needles around the screen of the air filter. Only took a few seconds to pop off ...


3

Simply cranking the car for 10 - 15 seconds should prime the carb. Crank the car for about 15 seconds Stop for about 15 seconds Pump the accelerator petal twice Crank the car again, if it doesn't start immediately keep cranking the car for a maximum of 15 seconds. Stop Wait at least 2 minutes, this is to prevent damage to the starter. Then go back to step ...


3

Two main reasons: Already some races require restrictor plates to keep the speed down, so swapping out the carburetor for modern fuel injection would increase the need for restriction. It is easier to inspect and monitor a carburetor, therefore it is more fair for each team since it is harder to cheat (or at least easier to get caught). However, from ...


3

Found the culprit the jets were fine, however the float bowl was full of residue and water, as well as the jet carrier bolt being snapped in half so the jets were moving along to where they were not able to fuel the cylinder. After a full strip down, rebuild and calibration its now firing on both cylinders correctly.


3

I'm not sure if the answer is still relevant, but I own the XR650L big red pig and may say that it's rather safe to mess with the carb of this bike even if you don't have specific skills. It's very forgiving unless you do something really wild. I used to ride about 500 km on my with mixture being extremely lean and was lucky enough to have my engine ...


3

Jetting a carburator - short answer You will require two things, probably. A size larger mainjet An adjustable needle jet Your main jet sits in the floatbowl, it's number 11. Off idle and higher the main jet contributes more and more to air fuel mixture as you open the throttle to wide open where the main jet is 99% of your fuel delivery. The ...


2

In addition to Troggy's sequence, make sure that the clamps on the airbox boots, and the intake boot are fully loose with some slack, and using some heat from a hair-dryer or heat gun will make the rubber boots much more supple.


2

On my old bike I had to pull the fuel tank off to get the carbs out. If anything it will make the job much easier in terms of access for your hands.


2

I'll assume first that you've tried spraying carb cleaner into it since you've had it out, so your question is more about what other adjustments there are, specifically relating to the idle. Beyond the Mixture screw you mentioned, there is usually 'Pilot Jet(s)' that allow some fuel regardless of RPM (as opposed to the 'Main Jet(s)'), and if they get gummed ...


2

The back pressure and flow change of the exhaust will have an effect on the combustion and mixture. Usually with a free flowing exhaust, you have to rejet the carb a little richer and with a free flowing airfilter, doubly so. Running it without an airbox is making it worse, the mixture is already lean and stuffing more air down the bores isn't going to help ...


2

Yes, you can install it, but no, won't do anything for fuel consumption. Carburetors don't automatically adjust themselves to take advantage of new fuel characteristics or other changes in the engine's combustion characteristics. Nano fuel economizer does the same job that your engine oil does. So, if you regular put new oil in your car, you're already ...


2

Because the air pressure being comparatively low at high altitudes, it might cause the above mentioned problems. And working on the carburetor if you don't have any experience is a bad idea, because it could ultimately lead to engine overheating and such problems that could ruin you engine. Four Strokes have a better tolerance towards an engine running lean ...


2

Your best bet is to get a replacement carb. Some have had good luck rebuilding them, but for the trouble of it, it's just a lot easier to buy a new one off the internet. Personally, I can never get them to run right after a rebuild. You can usually get one for less than $50 depending on the model. After you put a new one on, ensure you have a cut off valve ...


2

The 1998 XL650 has a fuel petcock that has a safety feature on it, as do many other bikes of the gravity feed carb era from about 1980 to present. Since you are running an XR650 you should not have the vacuum line. There is a vacuum line that runs from the manifold side of the carb to the petcock on the XL650. When the engine is turned over and creates ...


2

By removing the baffles you have reduced the amount of restriction and backpressure. This has the effect of making the engine run lean. If you get the carbs tuned so that it's running properly, it should run as well as it did before you performed the baffle-ectamy. With a free-er flowing exhaust it may even run better. But that's only if the original ...


2

Converting Carb to EFI is possible , it can be a DIY if you know what you are doing. You can start by looking for the below basic things to get a rough idea of the work you are going to do. Fuel Injectors Throttle Body An ECU All of the sensors(MAP,O2 etc) New Ignition system(Recommended not mandatory) Fuel Pump Fuel Pressure regulator A whole lot of ...


2

Depending on the make/model/engine, you might be able to find a newer version of the engine that already had EFI installed. If this is the case, you can search local junkyards and ebay to find a wiring harness, ECU, sensors, intake and exhaust manifolds.


2

More than likely what the problem is, your float in the fuel bowl is shot. When the float is shot (ie: doesn't float correctly in the fuel), too much fuel is let into the carburetor and causes the exact issues you are talking about. You may be able to get a new float and needle valve (very likely), but you may just be better off buying a new carburetor. ...


1

Your description is making me question your diagnosis so far, in terms of is it one cylinder affected or all. Because a GSXR should be able to run (badly) on 3 cylinders, and cleaning the fuel cap shouldn't make a difference to just one cylinder. From your description i'd start by replacing the fuel and ensuring it flows freely to the carburettors. (is it ...


1

This is a carburetor issue, most likely caused by ethanol gas. Ethanol laced gas reeks havoc upon small engines. The easiest fix for it is to purchase a new carburetor for it, due to paying the price for a replacement carb outweighs the cost in time and frustration which will be brought upon you trying to rebuild it. I have tried to rebuild small engine ...



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