Question about Garden

1 Answer

RUNS ROUGH-BACKFIRES STARTS GOOD THEN DIES-IS IS IN NEED OF CARBURETOR ADJUSTMENT OR IS IT POSSIBLY VALVE ADJUSTMENT? THERE APPEARS TO BE NO WAY TO ADJUST CARBURETOR AIR FLOW AS OPPOSED TO OTHER ENGINES. DO YOU THINK THERE SHOULD BE A VALVE SPACING TEST DONE? THANKS FOR YOUR REPLY!

Posted by on

Ad

1 Answer

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points

    All-Star:

    An expert that got 10 achievements.

    MVP:

    An expert that got 5 achievements.

    Brigadier General:

    An expert that has over 10,000 points.

  • Master
  • 4,088 Answers

In a 2-stroke engine, the valving is done by the mechanical relationship of the piston position in the cylinder. No adjustment is possible other than grinding the cylinder ports or changing the piston skirt shape. You need to check the fuel filter (in the tank), air filter, and muffler for plugging. Because the engine is designed to burn a small amount of oil with the fuel, the muffler tends to plug over time. Check the fuel lines for decay or other damage. The carburetor has a rubber diaphragm in the lower chamber that decays over time as well. Go to: http://www.drystacked.com for a 12 page article on Walbro brand carburetors that are typical of chain saw carburetors. Good theory and troubleshooting information. 2-stroke engines are picky about air leaks behind the carburetor. Hope some of this helps!

Posted on Aug 05, 2010

Ad

1 Suggested Answer

6ya6ya
  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

Hi there,
Save hours of searching online or wasting money on unnecessary repairs by talking to a 6YA Expert who can help you resolve this issue over the phone in a minute or two.

Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.

Here's a link to this great service

Good luck!

Posted on Jan 02, 2017

Ad

Add Your Answer

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

2 Answers

How do you adjust idle speed 1991 johnson 100 hp


not important, what's important is that they are absolutely clean, including the four brass high speed jets located in the bottom center portion of the carburetor.

That model engine's carburetors has fixed jets, BUT if the slow speed jets are adjustable, earlier model carburetors have been installed. If so...................

The four adjustable needle valves control the flow of fuel in relation to the set air flow, adjusted as follows (if needed).

(Dual Carb V/4 With 4 (2 each carb) Slow Speed Adjustable N/Valves)
(J. Reeves)

The adjustment procedure of the carburetor slow speed needle valves follows. NOTE... if the needle valves turn too freely, replace the nylon bearing retainer (the nylon item at the front of the carb that the needle valve goes through first) with the newer type RED retainer #315232. If your engine has that weird linkage that connects all four of those needle valves, the newer RED retainers will enable you to discard that linkage. The RED retainers make it impossible for the needle valves to vibrate out of adjustment.

(Carburetor Adjustment - 2 Slow Speed Adjustable Needle Valves, each carburetor)

Initial setting is: All (4) Slow speed valves = seat gently, then open 1-1/2 turns.

Facing the carburetors, start with the top left needle valve, then the top right valve, then the bottom let valve, then the bottom right valve. It may be necessary to redo these steps to get the adjustments ideally set

Start engine and set the rpms to where it just stays running. In segments of 1/8 turns, start to turn the S/S needle valve in. Wait a few seconds for the engine to respond. As you turn the valve in, the rpms will increase. Lower the rpms again to where the engine will just stay running.

Eventually you'll hit the point where the engine wants to die out or it will spit back (sounds like a mild backfire). At that point, back out the valve 1/4 turn. Within that 1/4 turn, you'll find the smoothest slow speed setting.

Do not attempt to gradually adjust all four of the valves at the same time. Do one at a time until you hit the above response (die out or spit back), then go on to the next valve.

When you have finished the above adjustment, you will have no reason to move them again unless the carburetor fouls/gums up from sitting, in which case you would be required to remove, clean, and rebuild the carburetor anyway.

Jun 28, 2017 | Cars & Trucks

1 Answer

What should I try next, I adjusted the valves, it turns over, then backfires, but still won't start


if you have the valves set correctly. try a shot of carburetor cleaner in the opening of the carburetor. if it starts you have a carburetor problem. need to be cleaned or rebuilt. the backfire is usually a sign of valves or timing. you might take the flywheel off and check the shear key to be sure it hasn't sheered . is the spark plug good and gaped right?

May 19, 2016 | Garden

1 Answer

Engine keeps backfiring under load motor is an enduro xl 13.5 hp


Need Make/Model/Year/Engine Model/Deck Size, and hours on meter if you have one. A short description of the events preceding the beginning of the problem is also helpful.

Several possibilities:
1. Needs a valve adjustment or a valve job. Start with adjustment.
2. Needs new plugs. Start with new plugs.
3. Shear pin under flywheel is slightly damaged throwing off the timing. Remove flywheel examine shear pin for any damage. Just go ahead and replace it; if it even looks nicked or sliced.
4. Coil, or spark plug wire, is going bad. Very hard to test a coil for weakness without test equipment that the average person doesn't have. Check the first 3 problems, first. If it still backfires, then replace coil.
5. The other thing that causes backfire is fuel mixture too lean. On a small engine this is not usually an adjustment problem. It may be the fuel system/carburetor is dirty or partially clogged. It may also be an air leak in the gaskets of the intake manifold. If nothing else solves the backfire, remove the carburetor and clean or rebuild it. This is the least likely of the options so save it for last.

If compression is good and cylinder leakage is minimal, but a cylinder is misfiring or shows up weak in a power balance test, it indicates a fuel delivery or ignition problem (fouled spark plug or bad plug wire). A power balance, or cylinder balance, test should be run on a twin cylinder engine.

If an engine is hard starting, runs rough, misses or lacks power, run a cylinder balance test to determine if both cylinders are operating to their full potential. You will need an engine tachometer, a spark tester, and an insulated screwdriver.

1. Using the spark tester, with the plugs in, start engine and verify spark is equally good on both cylinders. Remove spark tester.
2. Connect engine tachometer.
3. Run engine at top no load speed. Note rpm.
4. Ground one cylinder spark plug with screwdriver. Note rpm.
5. Ground other cylinder with screwdriver. Note rpm.

The difference in RPM between the cylinders should be less than 75 rpm. If the difference between the two cylinders is greater than 75 rpm, the cylinder with the least rpm loss is the weakest and is a potential problem.

Note: If the spark plugs are new this could be an indication of a weak coil. Of course it could also be compression (rings), or valves.

Mar 24, 2015 | Garden

1 Answer

Running rough, backfire, hissing sound


Hi Anonymous, be sure to check your intake seals, and the usual suspects are:
1. Spark plugs in bad condition or partially fouled.
2. Spark plug cables in bad condition or leaking.
3. Spark plug gap to close or to wide.
4. Faulty ignition coil, module and or sensor.
5. Battery nearly discharged.
6. Damaged wire or loose connections at battery terminals especially the ground cable at BOTH ends, ignition coil, or plug between ignition sensor and module.
7. Intermittent short circuit due to damaged wire insulation.
8. Water or dirt in fuel system, carburetor or filter.
9. Fuel tank vent system plugged or carburetor vent line closed off.
10. Carburetor controls misadjusted.
11. Damaged carburetor or intake seals.
12. Loose or dirty ignition module connector at crankcase.
13. Faulty MAP, CKP, and or CMP sensors.
14. Incorrect valve timing.
15. Weak or broken valve springs.
16. Damage intake or exhaust valve.
For a prime suspect please visit website below and good luck:
Big Twin Carb EFI DTC Intructions codes Harley Davidson Forums Harley...

Btw, I’m available to help over the phone in case u need at https://www.6ya.com/expert/gregg_c0ec1df182c7330e

Oct 15, 2012 | Harley Davidson FLSTC - FLSTCI Heritage...

1 Answer

My Sears Riding Mower Runs Rough & Backfires


don't know the model but check the valve adjustment

Apr 07, 2012 | Garden

1 Answer

My 86 suzuki intruder 700 backfires out the exhaust at idle. and makes a tapping noise. i already did a valve adjustment an new plugs


It could be the speed of one carburetor is faster than the other. This causes the backfiring as well as forces one cylinder to run lean which causes the tapping noise. You will experience an identical tapping or "ping" when you get close to empty on main fuel and need to switch to reserve. Most likely you or the previous owner unknowingly adjusted the speed of the rear carburetor down because of the high stock idle not realizing the front carburetor needs to be slowed down to match. While running simply turn the idle adjust screw clockwise on the rear carburetor until the idle smooths out and the backfiring/tapping stops.

Sep 20, 2010 | 1995 Suzuki VS 800 Intruder

2 Answers

Vstar 1100 idling rough and backfiring letting off the throttle


It sounds to me that your carbs might be a little gunked up - you mentioned the gas may have been old, so it's possible that the smaller (idle) jets are slightly plugged up. Fresh fuel might do the trick and/or you could try using a fuel system cleaner and water remover. This problem might 'solve itself' with a little time.

As far as the backfire - this might be either from the carb issue or it could be related to that rattle you mentioned - you could have a loose connection at or near the head - this can **** air and cause a backfire.

I hope this helped!

Jun 09, 2010 | 2003 Yamaha V Star 1100 Classic

3 Answers

2002 buell blast is running rough - missing - backfiring


hard to say w/ seeing it; it does sound as if they replaced everything w/o really finding the problem first; try better fuel and clean petcock; when dies is it electrical( all lights out) or does it sputter and choke off? sorry; I know it can be frustrating check all wiring under seat looking for loose or broken connectors or ground wires

Jun 28, 2009 | 2002 Buell Blast

2 Answers

Snow blower starts right up but dies once i engage the blades?


if its a 2 stroke (gas oil mix) there is an air leak in the crank case. a new gaskit is in order

Dec 30, 2008 | Ariens 34 In. Zoom Series Riding Mower

Not finding what you are looking for?
Garden Logo

Related Topics:

368 people viewed this question

Ask a Question

Usually answered in minutes!

Top Garden Experts

Dennis Key
Dennis Key

Level 3 Expert

2478 Answers

john h

Level 3 Expert

16485 Answers

Marvin
Marvin

Level 3 Expert

81400 Answers

Are you a Garden Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...