Question about 2011 kawasaki KLX 250

1 Answer

Motorcycle is losing compression and noisy

Recently some 500 miles ago i replaced the cylinder but after riding some miles Piston skirt touched the cylinder from both side. crosshatch isn't visible in skirt area of cylinder only.Pistons rings haven't seated yet. how can it be possible while all manufacturers give proper clearances between Piston and cylinder. i never overheated or abused this motorcycle. in this case what should i do ?? ride the bike till rings seating, is there any scope for rings seating after this incident or open the cylinder and hone it with oversize rings ??

Posted by on

Ad

1 Answer

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points

    Top Expert:

    An expert who has finished #1 on the weekly Top 10 Fixya Experts Leaderboard.

    Superstar:

    An expert that got 20 achievements.

    All-Star:

    An expert that got 10 achievements.

  • kawasaki Master
  • 53,757 Answers

If it is a water cooled engine the ring gap at the bottom of the cylinder should be around .010"
rings have to be installed the correct way up or the compression doesn't help push the rings against the cylinder walls for effective seal
piston skirts will touch the cylinder walls as the pressure pushes the piston to one side as it pushes the piston back down the cylinder
I have to ask did you put an old piston back in the new cylinder
was the new cylinder standard size or over size
what was the ring gap before you fitted them to the piston
did you use new rings or the old ones --maximum rin gap is .025"
rings don't wear in , just wear out
why did you replace the cylinder in the first place
was it because of low compression or taper wear
as silly as all this seams it is all very relevant to your question

Posted on Mar 11, 2016

  • Anonymous
    Anonymous Mar 11, 2016

    No i installed new standard size piston and rings with new cylinder, my motorcycle was burning oil.

  • Bill Boyd Mar 11, 2016

    I think you have to go back to basics and that means pulling it down again and start from scratch
    you could give the bore a light hone but you will be doing a lot of honing to get it big enough for the next size rings so that will be out of the equation
    The purpose of honing is two fold
    one thing is to give the bore surface something to hold the oil and lubricate the piston and rings and the second is to create a turning action so that the rings rotate in the ring grooves ---honing angles of the hatch section are set for best actions
    remove the rings from the piston and measure the ring gap at the bottom of the bore
    use the piston up side down to get the ring square in the bore
    measure the gap using a combination of feeler gauges
    as I said for water cooled engines that gap should be no smaller than .010" and no bigger than .025"
    the closer to .010" the better as that lets the least amount of compression past the piston
    Now if the gap exceeds say .015" then you could fit .010" oversized bore rings and use a fine mill file to get the gap back to .010" rings ( the oversize rings will not fit in the bore to start with so you have to be careful in the filing to get the ring in and then file to the correct gap
    remember that you are filing a circumference so a small amount equals a big gap
    check the crown of the piston (top) as many have an arrow to indicate that the piston has to be fitted with that arrow facing the front of the engine ( stator end )
    next rings are marked with a top sign etched in them and that means that the ring has to be fitted with that top facing to the top of the piston
    lastly when installing the piston and ring assembly use liberal amounts of engine oil and ensure that the ring gaps are equally spaced around the piston (120 degrees between each gap)
    with the gaps right, hone good, piston in right there is no reason that the job will be successful
    NOTE -- if the engine is air cooled then the ring gap is a lot more for minimum than the .010" but everything else is the same ( check the new gap with a bike rebuild shop)
    Some times the quality of oil used has to be as specified as a multigrade oil will quickly glaze the bore and allow it to burn oil as the rings do not get a chance to seal on the hone marks
    Above all a good workshop manual will be of enormous help in the assembly procedures

×

Ad

1 Suggested Answer

6ya6ya

6ya staff

  • 2 Answers

SOURCE:

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:

1 Answer

Can i continue riding with this cylinder which has scuffing on piston skirt side both intake and exhaust. see photo in comment.


Hi, Ronnie piston scuff on the bottom 15mm of the piston skirt is normal I would not pull the top end apart unless your compression falls below 100 PSI or your oil consumption is more than 1 litre per 1500 KM for more information about your question and valuable "FREE" downloads that you will need please visit the websites below. Good luck and have a nice day.
http://listpdf.com/sp/spare-parts-catalogue-hero-honda-pdf.html
http://www.heromotocorp.com/en-in/uploads/maintenance_schedule/maintainance_KARIZMA-ZMR.pdf
Hero MotoCorp 2014 Karizma Specifications Hero MotoCorp 2014 Karizma...
Hero Karizma

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

Mar 19, 2016 | 2006 Hero Honda Karizma

1 Answer

Very minute vertical scratches on cylinder wall at both side skirt area only.


Hi, Shekh my question is why you are pulling apart a new motorcycle engine? your piston cylinder wear is normal if you have access to a berry bush hone rehone the cylinder wash the cylinder in hot soapy water and dry with compressed air then quickly swab a coating of motor oil on the cylinder walls as a little surface rust may try to form for more information about your question please visit the website below. Good luck and have a nice day. http://www.bcmtouring.com/imp/Pulsar_DTSi_Workshop_Manual.pd Pulsar Workshop and Parts Manual Team BHP
https://www.facebook.com/media/set/?set=a.497832643584730.119398.177568422277822&type=3

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

Jan 06, 2016 | 2011 Bajaj Pulsar 150

1 Answer

Why is my engine making a knocking noise, could I possibly get a list of things that cause knocking? It's a 1995 Buick century special, four cylinder.


Many things could be the cause. Common ones are:

  1. Low oil level.
  2. Low oil pressure due to worn out oil pump.
  3. Connecting rod knock (part of piston assembly)
  4. "Piston Slap" - this occurs when the cylinder wall gets worn into a cone shape, wider at the base from the side-to-side motion of the piston over millions of cycles. The wear gets to the point where the piston skirt (bottom edge) hits the side of the cylinder wall as it hits the bottom of the stroke and begins moving upward. Eventually the skirt will break off and the engine will need rebuilding or overhaul.
  5. You could also have a simple valve tap, as you are not really defining knock, although valves usually are more of a ticking noise rather than a knock.
  6. If the knocking only occurs on acceleration, you could have what is known as "octane ping" from fuel that is too low in octane. Not likely with a four cylinder, but some really cheap gas grades are occasionally guilty of being less than advertised for octane.
  7. There are even a few transmission issues that can cause knocking, so make sure you narrow down the issues before diving in too deep.
Hope that helps!

Sep 16, 2015 | Buick Cars & Trucks

2 Answers

Volvo 940 Troubleshooting


What you are probably hearing is referred to as "piston slap". It occurs over time as the side-to-side motion of the piston as it moves up and down in the cylinder slowly wears the lower walls of the cylinder, changing it more cone-like. This causes the bottom edge of the piston skirt to strike the bottom edge of the piston wall as it transitions from its lowest point to begin its upward stroke. This was a issue on the Volvo Turbo engines. Google it and you will see that they made changes in 1993 to help prevent this. This problem will not go away. Eventually you will break a piston skirt and that will be the end. If you can, get the engine overhauled before the damage is permanent.

Nov 08, 2013 | Cars & Trucks

1 Answer

1998 Honda passport making a very loud knocking sound on start up and when excelarating. Top passanger side of engine.


Could be a piston slap, where the piston skirt is slapping the cylinder wall. If that is the noise, the piston would need to be replaced.

Jun 20, 2013 | Cars & Trucks

1 Answer

I ride a 1986 shadow 500 with 32000 miles. recently it started acting up. the rear cylinder cuts out as i ride and it can last for several miles before it picks back up. At the same time, the RpM display...


You need to check for spark when the back cylinder is not firing to see if that is the problem...from there it will be easier to troubleshoot...also check for vacuum leaks.

Jul 26, 2011 | 1986 Honda VT 500 C Shadow

1 Answer

I have just replaced the pull cord on my whipper snipper however after fixing it im having trouble getting the actual motor back on to the shaft. It fits in but stops about 5mm short from all the way.


You probably have the counter weights from the shaft hitting the bottom of the piston skirt. To remedy this, you will have to pull the piston/connecting rod off of the shaft, turn it around and install it the other way. If you notice, the piston's skirt is longer on one side than the other in most cases.

Jan 09, 2011 | Garden

1 Answer

I have a 2000 kdx 220r the piston skirt broke cylinder is ok but skirt pieces in case do i have to split case or can i dig them out


Sorry, chances are you will never be able to fully flush the particles out without splitting the cases. Might as well change bearings at the same time, etc., etc....

Nov 02, 2010 | 2002 kawasaki KX 500

1 Answer

What causes piston slap?


a common cause is carbon on the top of the piston or on the skirt, this makes the piston tilt from side to side under power and causes noise, the other is a worn piston or a cylinder that is not honed to the right size and piston can move excess, another is a cracked piston

May 25, 2010 | 2002 Honda CR-V

Not finding what you are looking for?
2011 kawasaki KLX 250 Logo

56 people viewed this question

Ask a Question

Usually answered in minutes!

Top kawasaki Experts

Arnie Burke
Arnie Burke

Level 3 Expert

6090 Answers

Marvin
Marvin

Level 3 Expert

85222 Answers

ROB

Level 3 Expert

858 Answers

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

Answer questions

Manuals & User Guides

Loading...