Symptoms of tight valves motorcycle Jul 23, 2010 · As mentioned, valve lash usually changes early in the engines life (<20,000 miles). Take the time and check your valves. Aug 16, 2004 · If the pushrods are adjusted too tight, is it possible to still hear the same ticking that is usually associated with too much valve lash? I don't know the brand of pushrods, but I've adjusted the pushrods 3-4 times, each time going a little tighter (not enough to tap a piston) and the ticking has not changed. Oct 19, 2005 · By the time there's evidence that the valves need adjusting, your valves, seats, or other components may have already suffered. Aug 6, 2008 · Valve lift can only be changed by adding a performance cam. Nov 14, 2014 · when you wait, for quiet valves and poor starting, the seats of the valves and possibly stems are already burnt, cannot be fixed by adjustment, the seats need to be machined, the valves need to be replaced before the weakened stem snaps, launching the valve thru a piston, bending rods and everything that goes along with that Feb 20, 2014 · valve adjusting too tight valves have the following symptoms: 1. May 23, 2017 · Valve Adjustment DIY: https://youtu. Valve lash adjustment prevents this damage from occurring. – Quieter engine operation, but at the cost of performance and reliability. quiet=tight. I've got 1 cylinder with two valves on my GY6 engine. The symptoms of low compression can be several things. Valve Clearance Check and Adjust If the valve clearance is too small, the valves will never fully close when they should be doing so and this will eventually burn part of the valve surface off and cause a constantly misfiring engine. Loose valves will tend to be noiser and wear the valve train by abruptly hammering the valve open without a takeup ramp. Fact is that the valves in the cylinder are made to handle normal operating temps and those temps should not be able to damage them. Feb 20, 2024 · Lack of Lubrication as a Cause of Valve Train Noise. Engine idling: Leaky exhaust valve stem seals can cause engine idling to be rough or Jan 26, 2015 · “These work great with either a short-travel hydraulic roller tappet or a solid lifter at the tight limit of possible lash setting for aluminum blocks and heads, around 0. Make sure they aren't grounding out from the heat of the engine. That also changes valve duration, the amount of time(in degrees)that the valve is open. Your dirt bike will struggle to start, the bike will misfire randomly, the misfire will become more and more frequent as your bike loses compression, and finally, your bike will feel sluggish as it struggles to build power. 002". Always keep your engine valves adjusted according to the manufacturer’s specifications. low power or stalling when warm; 5. So, valve clearance is less about finding the perfect clearance for your valves but instead ensuring they fall within a Overly tight valves can cause instability during idling or even prevent the motorcycle from maintaining idle, compromising overall smoothness and the riding experience. Sent from Motorcycle. Mar 7, 2024 · I recently got my 2000 Sprint ST 955i serviced (45K miles) and apparently the valves were all over the place - some very loose, some very tight. The valve springs are Aug 21, 2008 · If the valves are out of spec it can cause excessive wear to the valves and the valve seats. Checking valve clearance is pretty easy. Too tight and the bike may be hard to start. Engines with valves in spec are more efficient. You have a classic example of a bike whose valves were never touched; another couple thou and you'd have had a toasted valve. When the intake valves get too tight they will cause hard starting and poor idling. Aug 18, 2023 · This recession happens faster than the material between the cam lobe and the follower wears. com Mar 21, 2012 · I have read plenty about valve issues with the 450's and how hard statring is a usual symptom. As well as affecting the functioning of your engine, a tight valve clearance can lead to a series of symptoms that may compromise your car’s performance and efficiency. Good luck. I guess you could change valve lift by making a tight valve lash, but that leads to burned valves. He thought about it some and re-adjusted that clearance to bring it back to spec. Increased oil consumption: Leaky exhaust valve stem seals can cause oil to be burned in the engine, leading to increased oil consumption. Might be hard to start when HOT. Too tight and the clearance will shrink to zero when hot, potentially holding valves permanently open causing poor running and burnt valves and seats. Usually your service manual will tell you when to check valveclearance. Jan 2, 2018 · As an engine runs, its valve train is subject to some wear of cam lobes and tappets—wear that tends to increase cold valve clearance. Now on five valves I run them all loose to the point of the keepers dropping off and falling into the lower end. This will invariably cause low compression due to valves not sitting when they should. Now it rides like a new machine - just feels 'tighter' (in a good way). Can tight valves cause hard starting? Tighter valves will not make any new noise. No space means the lifter may be constantly holding the valves open. Nov 28, 2023 · Motorcycle engine valves should not be confused with the throttle valve, which regulates the amount of air drawn in, nor with the exhaust valves: the latter, also known as backpressure valves or exhaust control valves, are specific types of gate valves found in 2-stroke engines. Some bikes like to be a little looser than spec but save that for later and just make sure it's within spec. Something to consider in hot climates. If the valves were too loose it could have meant possible build up of carbon or something on the valve face preventing full closure, or wear on the bucket/cam lobe interface. May 31, 2023 · Symptoms of Tight Valves Difficulty Starting the Engine. They are used to modify the strength of the backpressure wave of Jan 2, 2010 · Usually tight valves cause hard starting although checking them wouldn't hurt. In essence, valves serve as the combustion chamber's doors, opening during the intake stroke to let new mix in, closing during the compression and power strokes to keep out air, and opening during the exhaust stroke to let out the wasted gas. Hey everyone. 00:02 09:12 Brought to you by Leaf Group Particularly tight lashes can cause wear and tear. I also thought valves clearances tightened over time, but noted, an increasing gap is likely one, or a combination of lobe wear, bucket wear, shim wear, and possibly wear on the tip of the valve that contacts the shim, but as the internals all looked real clean, I am also more inclined to believe it is carbon buildup. Jul 3, 2017 · Getting your bike’s valve clearance checked out is important to make sure that the engine is running smoothly and at its optimum range. Tight Valves. Oct 29, 2021 · Slappy valves are happy valves. It's possible that the valve seats got burned from low clearance and exhaust gas constantly leaking. Do this by removing them with a screwdriver or opening them using a special valve tester tool. – Engine misfires, reduced power, and poor fuel economy. Sep 22, 2022 · Any four-stroke engine's motorcycle valve mechanism is fairly simple, both conceptually and practically. Mar 2, 2023 · Leaky exhaust valve stem seals can cause oil to leak into the combustion chamber, resulting in blue-gray exhaust smoke. Dec 31, 2011 · Tight intake valves will cause an uncontollable high idle, and tight valves in general will toast your top end parts. Q: Can tight valves cause low compression? Tight valves will open sooner, wider, and stay open longer. 37ºC in Bangkok today and the oil temp stayed at 5 bar. Best remove the OHV covers and measure lash (clearance) with feeler gauges. About 2 hrs running time later, the head came off that valve and trashed the cylinder head and cylinder. Mar 4, 2022 · Thanks guys for taking the time to reply. Without it, friction increases, leading to noise and wear. But not all motorcycles require valve adjustments, so why does yours? Karl Engellenner, expert motorcycle Jul 6, 2012 · What's your take on this statement? Meaning, a valve on the loose side of the spec is better than on the tight side - so it makes a tapping sound. By then its too late and the sealing faces on the valves will be burnt and no longer sealing properly, requiring a major strip down and rebuild. Id check the pulser coils. but the truth is, the quieter your valve train is the more you have to be concerned. If a valve is too tight such that it remains open, that particular cylinder will probably backfire (tight intake) or cause excessive bluing of the exhaust header pipe (tight exhaust) and will have a direct effect upon your machine's performance. If it has four valves I run one tight, the next one not so tight, the thrid one a little loose, and the last one sloppy loose and noisy. Tight one for a loose one, loose one for a tight one, and save some money. Also, tight valves, as is little to no clearance, will run hotter and may bleed off compression and lead to power loss. the engine is spitting back through the carbs once the engine is warm; 4. Jan 9, 2008 · Sounds like a tight valve and if you are going to do a compression check, you will need to know if the valves are at least adjusted right to eliminate that question from the test. i would be hard pressed to believe that a bike with 15000 miles will be out of spec unless it was a lot of hard/race miles. JVB has a video that will walk you through it. You won't harm anything (well, generally speaking) with an overly LOOSE valve; But you will cause all sorts of problems with a TIGHT valve. If the valves are too tight, you risk burning your valves. On my KTM 640 I don't worry about a valve being too tight as the cam is of such design that the valves set in the seat for a fairly long time allowing the valves to cool. Once the valve warps and/or the seat pits, then you would see it by testing compression/leakdown. over time you won't notice the gradual degrade in performance but as soon as you adjust them properly, you WILL. Only when they're loose though. The May 25, 2022 · The Impact of Tight Valve Clearance on Engine Efficiency. After riding for a while,(full operating temperature) and I stop for gas or whatever, the bike if it doesn’t fire up right away (feathering the throttle) it takes some serious Nov 15, 2022 · There will be a number of problems as a result of tight valves. The symptoms of engine-valves that are too tight, are as follows: Bad fuel economy; Difficult to start; Stalling idle; The manual for my scooter states that the engine-valves should be checked/adjusted every 4000 kilometers. Author Topic: Valves way too tight--anything I should be concerned about? (Read 7745 times) (Read 7745 times) 0 Members and 1 Guest are viewing this topic. May 4, 2015 · Tighter valves will not make any new noise. Inadequate oil levels can cause valve components to grind against each other, sounding an alarm through ticking or knocking noises. But while valve recession may be considered normal, in many cases it is very rapid. 003 mm The bike does run however it is now making a loud tapping noise. Tight valves will give hard starts, running hot, backfires and stalling at idle. Can Valve Clearance Cause No Start? Yes, if the valve clearance is too tight, the valves may fail to close properly, leading to a loss of compression. 33mm. 006 mm and intake valve to . I was overheating after a short ride. At the same time, so-called valve seat recession also takes Symptoms. May 15, 2008 · If you think the valve are tight, then check them. My riding lawn mower valve lash adjust is more complex that my GS boxer. Or to use a different one, a tappy valve is a happy valve. Apr 19, 2016 · On a 5 valve engine, he found 4 valves slightly loose but one valve had a significantly reduced clearance. My question is: What to tight valves cause that makes it so hard to start? Does it hold the valve open longer letting in too much air/fuel? Mar 21, 2013 · When exhaust exhaust valve clearance is too tight, the valve may not be in its seat long enough to transfer sufficient heat. If the valve can't close fully, it won't have the opportunity to lose heat to the head. ” “In many cases, it’s acceptable to use mechanical lifters on a hydraulic camshaft if relatively tight valve lash figures are used,” adds Knight. She ended up having the head redone since the exhaust seats did not look too good. Oct 4, 2011 · Leaky valves don't usually cause what you describe, Scorch, and a faulty TPS or one that is out of adjustment will cause problems throughout the entire throttle range instead of a limited range. But all engines recede their valves, even liquid-cooled, multicylinder, moderately-loaded ones. My main issue is hot starting. Adjust only if needed. Aug 28, 2015 · Here are two commonly asked questions pertaining to motorcycle engine maintenance. Enjoy the videos and music you love, upload original content, and share it all with friends, family, and the world on YouTube. Mar 16, 2010 · agreed. Loose Valve Clearance Jul 28, 2009 · In my experience too tight valves only cause big changes when the clearance goes to zero and the valves start leaking. be/5gq0xQg0TAANote: at 1:33 I misspoke. Make sure you have the engine at TDC when adjusting each cylinder. 121,000 miles? Get a valve adjustment, basically. Replacing the stock cam with such. Jan 10, 2016 · Like many others my first valve check on my DL650 found one of the valves slightly too tight. blown head gasket; 7. I meant to say "when the piston is on its way back upwards". May 16, 2010 · Generally speaking, a valve adjustment too tight or too loose should not cause excessive smoking. Loose valves open later and close earlier, tight valves open earlier and close later. Had all the start symptoms of tight valves. Aug 17, 2007 · As an aside, I should mention that before you synchronize anything you'll need to make certain the rest of the engine is up to snuff. The symptoms of low compression. 11mm and Exhaust spec is . Mar 2, 2022 · However, the real danger is the valve clearance closing due to valve seat wear, which you cannot hear, and only becomes noticable when performance drops off and the engine can be dificult to start. That's completely normal. If the valves wear tight, it could cause a hard-to-start condition, erratic idle, performance loss, and other thermal dissipation-related issues. When valves are way too tight, they don't completely close, so exhaust gasses can leak past into the intake and the exhaust system, which can overheat a valve ("burnt valve"), warp parts of the head or block, damage the valve seats, and eventually cause the engine not to run anymore until you fix the head and valves. Increased Wear on Rocker Arms and Camshaft: Tight valves increase friction and wear between the rocker arms and camshaft. Oct 14, 2003 · You will porbably find your valves to be looser the second time you adjust them and tighter than spec the first time. Jun 10, 2014 · Too much clearance and the engine will be noisy and you will effectively lose valve lift. However, if a bike is out of tune in the valve department, it certainly could lead an inexperienced person to believe that there is a carb issue, causing them to fiddle with the carbs. Apr 4, 2020 · There are five easy signs your motorcycle needs a valve adjustment. Jul 20, 2007 · But tappy valves are happy valves as they seat better. If you take off the cylinder head cover for your bike, check each valve one by one. Valves tend to get less clearance and then they go silent. May 20, 2008 · Too tight of a valve on the exhaust means that the valve has seated, and deeply enough to cause a lack of clearance with the cam lobe at the bucket. One of the first signs of tight valves is trouble starting the engine, especially when it’s cold. Understanding the impact of tight valve clearance on engine efficiency is a critical aspect of vehicle maintenance. The inlet valves in the engine open to allow air and fuel into the cylinder, while the exhaust valves let the burnt gases out. Jun 22, 2007 · If the clearance is too tight, the valve won't seat fully in the head. We would like to show you a description here but the site won’t allow us. Dec 31, 2014 · Tight valves do not cause engine firing anomalies unless the valve is so tight as to not seat completely. Doing a valve adjustment tonight, the Intake spec is . Jun 12, 2018 · What I have been searching for all over is a list of symptoms of intake valve adjustment out of spec and the same for the exhaust valves. The shims rarely wear out. 25-. Check the valves and the intakes were fine but both exhausts were out. I measured the Intakes at . May 26, 2022 · Related Posts: Grasping Motorcycle Transmission Issues and Fixes; Unveiling the Thrills of Riding an 80cc Dirt Bike: A… 6 Symptoms of Tight Valve Clearance: A Comprehensive Guide Nov 15, 2018 · Motorcycle valve adjustments can be inconvenient at best, but throughout the life of the motorcycle, many riders will eventually have to deal with it themselves or pay someone to do it for them. Both valves where very tight adjusted the exhaust valve to . Jul 27, 2012 · Good thing you decided to have a look, that #4 exhaust valve is approaching danger-ville. Some bikes it's 6000km, some 12 or even 24. So the only way to know for sure which way your engine is going is to perform a valve inspection/adjustment. Aug 4, 2015 · Valve timing, as stated aboove, does not affect the fueling. It's the normal valve wear pattern. 02 mm is enough to hit the valves, tolerances are incredibly tight on super bikes). Clogged carb vents also cause fuel starvation. It's much better to be too loose than too tight. Too-tight valves (insufficient valve lash) will not be noisy yet are more likely to result in major problems such as a burnt valve, and may also cause MPG issues. I agree. If you notice that your bike is having difficulty starting, check the valve clearance as a If it was at zero clearance that means the valve is actually being pushed open (never closing) at TDC for every cyclinder that had zero clearance (and yes even -. Loss of power due to valve not closing properly, engine will lose compression. Mar 21, 2012 · I have read plenty about valve issues with the 450's and how hard statring is a usual symptom. melted piston Feb 20, 2010 · It was explained to me a slightly looser valve clearance will cause the valve to stay closed a fraction of a second longer allowing more heat to dissipate into the valve seat, hence a slightly cooler running engine. That along with rejetting will keep the valves from burning. If you've got a mill that's down on compression with three tight valves and two fouled spark plugs, you can synchronize the carbs until you're blue in the face and the bike still won't run worth a lick. Let's see a 4 cylinder , 4 valve engine has 16 shims WOW, that adds up fast. Jun 12, 2012 · On a single cylinder motor if it was too tight and not closing then you would lose compression and I doubt it would run. . A valve that does not close properly will build up heat. Mar 7, 2025 · 5. Dec 31, 2019 · The way to tell if a valve is tight is to stick the minimum specified feeler gauge in between the valve stem and the cam lobe. Attached engine pic is a link to a video with sound. We went through this exercise with the GF's Sherpa. The only thing is when they are too loose, the process of fuel/air going in and gas going out is hampered by valves that don't open to their design limit therefore If the valve lash is too loose or tight, it will cause catastrophic damage. 012-inch hot. 03mm-. When the valve closes, it mates with valve seat in cylinder head to dissipate heat. Oct 31, 2010 · 5) It's very easy to say that your valves are fine-they don't need to be adjusted-it sounds ok-it runs ok. See full list on motorsocietyusa. Tight valves will be nice and quiet up until the time you lose clearances and burn a valve that no longer seats well enough to transfer it's heat to the cylinder head while it is closed. In my experience, shim valves need much less adjusting than your typical locknut valve assembly. Valve adjustment is important because it ensures the valves operate correctly, which affects the engine’s performance. That's just my speculation of what could've happened. You’d hear ticking, decreased power, and maybe rough idle if they were really bad. Jun 25, 2013 · Bottom line: If your valves were "tight" prior to adjusting them back to spec, expect them to be slightly louder than they were before. Get the valve cover off. 11mm and . With even 1 long season of racing, we see the valve stems making impressions into the valve shims. Let’s We would like to show you a description here but the site won’t allow us. My clapped out 2001 750 had 50k miles (80k km) and the valves were still within spec. Nov 19, 2020 · Tight valve clearances means the valves will stay open longer and run hotter (and quieter) with less time on the seat to lose heat to the head. Feb 27, 2020 · Valve clearances on motorcycle and car engines effectively relate to the gap between the top of the valve stem and the cam that operates it. Jan 27, 2015 · The line used for TDC was the one on the right. This is especially true with exhaust valves. When the exhaust valves get too tight they will also cause hard starting and eventually get hot enough to start melting - not pretty. Your motorcycle’s valve train needs proper lubrication to operate smoothly. When there’s insufficient compression, the engine struggles to start or may not start at all. Jun 29, 2012 · In most cases as the valve seat and valve head wear they start to pocket into the head, This reduces the clearances ,if the clearance is reduced to nothing the valve is held open slightly,this reduces the compression of the engine and in turn it will be hard to start . Best Solutions For Ticking Motorcycle Engines: We will give you some information on how to prevent ticking motorcycle engines. If it doesn't fit, the valve is too tight. Pre-ignition, valve lash, overheating, valve train failure, and increased fuel economy. When my TPS physically came loose and spun out of adjustment, the motorcycle nearly bucked me off. It will only take about 30 min to tear down and check them. overheating; 6. And even possibly have valve slap on the piston if they are far enough out. Valves are like kids, when they are totally silent, then you worry. Tight valves causes more leaks. The exact valve clearance for each vehicle is different and specified in the service manual. adjusting will take more expertise . Get ready with all the necessary equipment and weapons to At $10 to $15 per shim. engine is very quiet with no tapping sound from top end; 2. My question:. AND you are replacing good parts. Dec 19, 2008 · If the bike has two valves, I run one on the tight side, and the other a little loose. While this motorcycle had no symptoms of tight or loose valves, lets discuss some symptoms of either case. Over time, the constant flexing can lead to metal fatigue, cracking and valve failure. 09mm, and the Aug 10, 2018 · And if they are off, you may not sense a performance change. Aug 19, 2018 · Valve stems can wear from having too much sideways thrust due to stem-to-guide clearance being out of spec and allowing the valve to move laterally, which can cause the valve head to flex when it closes against the seat. Also valves normally burn up due to running lean which makes the exhaust temps sky rocket. Good news is you can swap shims between valves. It was my understanding from what I read this was the correct line to use. If the valve lash is too loose, the valve may not open and close fully, resulting in poor engine performance and decreased power. When the exhaust valves get too tight they will also cause hard starting and eventually get hot enough to start melting – not pretty. Also check the vent(s) on the carburetors. Valve recession is in fact the most ubiquitous valve wear condition one finds during an engine rebuild. Then, you won't be able to get the feeler gauge into the gap when checking. For example lets say the valve adjustment at some point was causing the exhaust to pop. Loose valves affect valve timing as the cam has to rotate further to start the opening and closing sequence. I have already discussed the five primary symptoms of tight bike valves and how to diagnose them. If your bike is suffering from symptoms like difficulties to start especially in the morning or lost of power even though you’ve sent it for regular servicing, it’s time to get the valve clearances checked out. So they were all set back to spec. Oct 3, 2017 · Engine-valves usually get tighter as they're used. It’s not just about Dec 15, 2011 · Can tight intake valves cause false lean symptoms? Or will it just make the bike run lean period? Lean symptoms such as popping, "blip" the throttle and a tad bit of a long time to return to idle, header starts to glow quickly, diminishes when riding around the block but still emanates a faint glow. Because the metals in the engine expand when they get hotter, the lash is reduced. Jul 4, 2021 · Setting the clearances too tight can prevent valves from completely closing (or not closing for enough time), which may cause extreme heat damage and complete valve failure. Weak or worn-out valves can also cause low compression on a motorcycle. Exhaust valves that are too tight can burn. The only evidence is likely to be losing compression in a cylinder because of the burnt valves/poor seating. Nov 30, 2011 · The "noisy" criterion is only half the issue, that just means one or more have too much play, which might contribute to inefficiency. Eventually a valve will break and possibly trash your whole top end. This allows them to cool down better as one function for valve seating is cooling besides closing up the combustionchamber. Starting problem – Overheating of valves, leading to burnt valve seats or damage. The procedure is simple on the modern boxers. Turn the engine 180 degrees to TDC compression stroke on the right side, line up the "T" mark, and set the right side valves to 0. com Free App Dec 18, 2024 · Symptoms/Effects; Tight Valve Clearance – Valves may not close fully, causing compression loss. This is why there is a service interval. May 4, 2015 · Tighter valves will not make any new noise. One exhaust valve had no clearance. tight=valve damage. Feb 3, 2022 · Step 3: Check the Valves. The tightness is measured between the valve and the lifter cams. This can cause loss of compression, or even destroy the valve by overheating because the head acts like a heat sink to dissipate the heat from the valve. the bike is hard to start (particularly when warm), 3. qbyp wtjaa yxyxos foywe nnx eshhm ysdzg tkzat zvrzlet rizcy ebku psck wtel jlp fyw