Question about 1993 BMW R 100 R

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Surging while riding, terrible fuel mileage. Am going to remove carbs, clean them and check all the jets, tears in diaphrams, slides. Just ordered new floats. Any other advice for me? This is a model directly from Germany and has 40 mm bings. Thanks for any help you can offer.

Posted by tricksv650 on


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Springs for the diaghrams are crucial items too!
but usually its the diaghrams leaking ! & dont forget to rebalance the carbs
Cheers rob

Posted on Jan 05, 2010


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Lawnboy 6.5 idles up and down and low power

Try a new spark plug and then clean the
carb jets very carefully. Remove the jets
and blow out all the carb passageways.
The jets being plugged cause a lean fuel
mixture which causes the surging.
Last resort is check compression and do a
engine rebuild with new crankshaft seals.

Jun 14, 2014 | Briggs & Stratton Lawn-Boy 10640 20-Inch...


Cleaning the fuel float bowl

Note: this procedure will often cure no start issues and or surging issues, or once done a little running after the fact will clear up surging issues as well.

Often gas with ethanol will cause gunk build up in the float bowl making your mower run badly and have a 'surging' behavior especially at low idle speeds, or cause it to not run at all (almost all gas has ethanol as an additive now for 'emission' reasons so assume you have it unless you KNOW you don't). This can take as little as a few weeks or a month or two of not running to happen. Frequently a simple float bowl and carb cleaning will resolve these issues completely or at least to get you back to a running point.

To clean the float bowl area, it's best to remove the carb. (make sure you pinch off gas lines with a vice grip or similar to keep it from spilling out and remove things carefully to avoid breaking seals on the intake)

Tip the carb over a catch basin or oil drip pan and turn it this way and that to pour as much excess fuel as you can. If your carb has a electric solenoid or an overflow screw on the bottom, removing this will let you pour fuel out of the bowl area.

To begin cleaning, Turn the carb upside down. Typically there are 2 or 3 screws that hold the bowl to the bottom of the carb. Do ALL of this over a nice metal tray that will catch any falling parts like small screws, carb jets, springs, plungers, etc.

Very carefully undo these screws and work the bowl until it breaks free of the seal

gently pull the bowl off the bottom of the carb. and you should see the float mechanism and main jet sticking out toward you. This visible area, all the orifices, and the bowl you removed are what you want to clean.

ANY orangish discoloration, sediment, or other gunk that is not obvious parts of the carb is bad news.. or good news because you're about to remove it and you found a problem that was worth fixing. If everything is clean, shiny, and aluminum and plastic looking, all is well in there, put it back together and move on to other DIY projects. :)

To clean it out assuming you saw at least a little orangish discoloration, a good pressurized can of carb cleaning spray is GREAT... HOWEVER, do not let carb cleaning spray get on ANY gaskets or rubber seals. The chemicals in carb cleaner will expand the rubber and make the seals not fit properly anymore and ruin them. (beware there is a TINY, impossible to see rubber seal on the plunger for the float so you MUST REMOVE THE FLOAT if you want to use carb spray to spray the metal on the carb or the jets while they are still on the carb. It may be better to just use a little gas in a metal tray and a soft toothbrush to scrub things off and clean them out. Typically it's just a pin you have to slide out in order to remove the float and plunger, it's sometimes a little tricky getting it back in just right.

You can also use your air compressor spray tool to blow out passages and dry out parts you are cleaning and it's great to blow out all the orifices you see in both directions ... BUT ... watch out because it is easy to accidentally blow out the jets and lose them! Also, wear eye protection ... seriously, do it, even if you're not using compressed air.

Once you have cleaned everything, make sure no little parts are in that handy metal tray you worked over the whole time. If there are any, find where they belong and put them back. Nothing in there is unnecessary... nothing!

Once you put it all back together, the carb will naturally refill with fuel and you should be able to start right up after a few seconds of cranking.

Any residual surging will often clear up after some run time, I like to use a little mix in gas carb cleaner after doing a carb cleaning. If my tractor has sat more than 2 months not running, I often check this before even trying to start to make sure I don't pull any gunk that did build up into the jets and clog them. Cleaning the bowl is easier than cleaning the orifices!

on Nov 15, 2013 | Garden


Carb. cleaning

gas goes bad after 30 days and after 6 months, Boy does it gum things up. i know this because, i do this for pleasure and my living. 99.9% of the time its the low idle jet thats going to be the problem. its the smaller of the two jets. the larger one is the main jet. remove the float bowl and with a very good screwdriver, remove the jets. those would be the little brass things with the hole in them. you must be able to see through these hole. so hold them up to the light and take a look. use a little carb cleaner and a air compressor to blow them out. if your carb has an accel. pump fill the float bowl with a little carb cleaner and make sure it works and that the diafram has'nt any holes or tears in it. you can check by holding the diafram up to the light you'll need to remove the air mixture screw and clean it as well. turn the screw inward and count the turns before you turn it outward. be careful there will be a small spring ,washer and o-ring. in that order. clean the rest of your carb with cleaner and she'll run like new. one other thing. the needle and seat of the fuel inlet.with the float in the up or full position, you should not be able to blow through the fuel inlet. you may need to adjust the float and or replace the needle and seat. otherwise fuel will continue to run causing it to overflow or worse fill your crankcase with fuel. i hope this helps alot of you. have fun and ride safe!


on Mar 02, 2009 | 1987 Yamaha FZ 600

1 Answer

Suzuki lt50 manual

have you tried starting with the air intake pipe/hose removed from the carb ? if still wont start i'd strip carb down and clean out the jets , not forgetting the idle jet at bottom of bowl , also check the diaphram pump is in working order , rubber diaphram still flexable not holed etckeep me posted if you wish

May 26, 2014 | Cars & Trucks

1 Answer

I have a 86 honda shadow vt 1100 has spark wont start

the Bike need three things to run Spark ait and fuel. if your sure you have spark then move to fuel, check if fuel is getting to carbs. if not turn on petcock if pet **** is on and still no fuel may need to add fuel or check and see if petcock is clogged. if petcock is clogged then remove gas tank and clear out any and all debres.

If you are getting fuel to carbs and bike still does not run, check air box to see that it hasent become a new home for mice. if bike has been sitting for a while 60 days or more (ethinol in gas REALLY cloges up your carbs) you will want to pull carbs and clean flote bowls and all air ana fule passages, main jet and emultion tube slow jet and emultion tube check and clean venturi slide and check slide diaphram for holes. Check all seals and floats (Floats: if the floats have any kind of a hole in them they will fill up with fuel and flood the float bowls) check float bowl pins ( some times they get stuck closed not allowing float bowls to fill with fuel.

If you are not sure you can do this that find a local motorcycle mechanic who can help you. to keep repair costs down you may want to bring them the set of carbs removed from your bike (if you are able to)

Sep 12, 2012 | 1986 Honda VT 1100 C

3 Answers

Lawnmower won't start

I am not having any luck with crossing the number you passed. I really need just the number off the engine air shroud just above the spark plug. Having said that. I understand you have a fixed speed automatic choke Briggs and Stratton engine without a primer bulb.

To gain access to the carb diaphram it is not that hard. The carb and gas tank are removable with just 2 bolts after the air-cleaner is removed. One bolt with spacer is near the gas filler opening and takes a 1/2 inch socket to remove. The other bolt is on the front bracket and is a 3/8 head. Once you have the bolts out, pull gently and carb will slide off of the intake tube.
Then tip the bottom of the carb toward you (STOP note the linkage position) and then remove the linkage.

Tank and carb off....

NOTE: The diaphram may stick to either the tank or the base of the carb so be careful when separating carb from the gas tank. Remove the 5 screws holding the carb to the tank and lift straight up making sure the diaphrm is not stuck.
The diaphram is under the carb and will have a spring on it if yours has an automatic choke. Note which side of the diaphram the spring is on. On the side of the carb there will be a rectangular plate with ONE 1/4" head on it. Remove the plate. This is where the choke attaches to the diaphram. Before removing the diaphram inspect it for holes in places where is not supposed to
have holes. If there are no holes visible on the bottom of the diaphram remove the diaphram by disonnecting the linkage inside the side plate. Again inspect the top of the diaphram for holes. If you find any tears or holes take the diaphram to your nearest lawnmower parts supply and get a replacement. They
usually cost around $6.00
If your carb has a single fuel adjustment screw turn it closed until it just starts to snug up counting exact number of turns from the original position.
Remove the fuel adjustment screw. If you loosen it until it is almost removed the whole assy will pull out with pliers while screw is still installed.
(O-ring type mating area) Clean the hole and reinstall the fuel adjustment jet.
Turn it closed until snug then adjust to original position.

NO HOLES in Diaphram or before installing NEW diaphram.
Check the fuel pick up tube for obstructions especially on the bottom screen.
You should be able to pass air though the tube orally. Noting the tube is free of obstructions install the diaphram by connecting the choke link on the side of the carb and install the side plate. Install the carb onto the gas tank and evenly tighten the mating screws. Then take the tank and carb assy to the engine and connect the carb linkage. Slide the carb onto the intake tube and make
sure the O-ring on the intake tube is inside the carb intake throat. Install the 2 mounting bolts for the tank and carb assy.

Test engine.
Install the air cleaner screw. Fill the gas tank all the way to the lip of the tank where the gas cap screws on. (This will ensure that the diaphram has gas in it) It should start within 2 or 3 pulls.
If it runs... your almost done.
Take the air cleaner foam and wash it with gas until clean. Then oil the filter with oil gently squeezing it to make sure oil is evenly distributed.
Once oil is evenly distributed SQUEEZE out all excess oil by squeezing the foam as tightly as you can. Then install the foam and air cleaner.

Task complete.
Thanks for using FixYa


Apr 10, 2010 | Yard Machines 24a 021h700 4.5 Horsepower...

2 Answers


Air filter needs to be installed and clean. Check the seal at the carb,for tears or loose clamps.Also make sure fuel filter is cleaned out or replaced(dirt trash or water will stop fuel flow). If fuel pump is electric fuses may need replacement. If you still dont get better results you may need carbs cleaned.Not just add cleaner to gas,but removed and debris removed from jets float valve seat or filters inside.

Apr 07, 2010 | 2000 kawasaki KDX 125

1 Answer

Idles but won`t accelerate

Change fuel filter.
fuel pump sounds fine.
Check for kinked or blocked lines.
If it has a fuel recovery cannister service it.

Jun 11, 2009 | 2001 Yamaha V Star 1100 Classic

2 Answers

Surging tecumseh engine on snow blower

Hi, You have gum or old gas in the main jet on the carb, turn your fuel off, stand the snowblower on the front blower housing with handles in the air, remove main jet from the bottom of the carb and clean. Jim

Jan 30, 2009 | Garden

2 Answers

New model ut08580 backpack will not start

check the fuek lines for hole and leaks, check the fuel filter and clean if necessary. remove the carbuerator and inspect the gasket; it should be soft and flexible, if it seems hard or brittle replace it. clean the carb with carb cleaner sray (available at any local auto parts store) and compressed air. make sure you get inside the small fuel rail holes. check the primer bulb for pin holes and seating/sealed properly. if that doesn't work have the carb repaired at a service center or replaced.

Nov 11, 2008 | Homelite Consumer Products Backpack...

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