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Found 28 results

  1. Hey guys, just asking if I can put a earlier z400 head on a later z400. My friend has a 2013 that needs a head but he wants only 600 for it.......
  2. Hey I have 2004 yamaha wr 450. It recently had head refurbishment and put back together ran for maybe half an hr and whilst doing shims noticed centre inlet cam journel wearing and scoring. Also no valve clearance at all on centre valve only. I was wondering could the cap be too tight and causing it as all other journels are perfect, no wear. could there be anything else that may cause just the one journel to wear? Any help would be appreciated as I've spent enough already lol. Also it doesn't have much compression in the kick starter but pressure test came up with 60 psi. Also almost impossible to start but thinking that's because of valve clearances they were all over the shop. Cheers
  3. Hello. Rebuilding my top end as the valves have stretched and need to be replaced. I need some confirmation of a few things: Are both the intake and exhaust valves titanium? Or just the intakes? Which piston should I go with for maximum longevity? OEM or aftermarket? Thank you
  4. I have a 2002 drz400s that just hit 11,500 miles. I've owned it about 1000 of those miles and they were done some highway, some urban street and some trail. I had an issue a while back with the float needle seat o-ring letting fuel into the oil, changed the o-ring and that seemed to be the end of it. At first the bike wasn't running great but after fixing that carb issue, a 3x3 mod and a JD jet kit I'm in love with this machine...which is why I'm very concerned about her drinking oil!!! Ive noticed over about the last 300 miles or so it has gone from full on the dip stick to about half. This morning I took her around the block to get her all warmed up and check the oil and it was about 3/4 of the way up the stick. This afternoon I did about 40 miles highway and 20 miles trail and came back and checked and it was half. I decided to dump a little oil in there until it read full on the stick. I"m confused because the bike is running pretty well and if it was drinking that much oil and had bad rings I would think this would be noticed. There are no leaks on the floor of my garage or any signs on the engine thats its leaking, also no sign of oil in the exhaust. So ...What could it be, is it immediately serious, and can I just keep adding oil and get another 1000 miles out of it before I have to rebuild her?
  5. Okay so I need some advice. I have a 14' kx450f and I just went to check the valve clearances. The manual specs are exhaust: (0.017 - 0.022) and intake: (0.010 - 0.015). The left exhaust measured at 0.020 and the right exhaust at 0.019. The left intake at 0.010 and the right intake at 0.011. I know they are technically in spec but my question is should I shim the intake because they are on the tighter end of the spec or just leave them alone? Bike starts and runs fine just a routine check but wanted some opinions. Thanks in advance!
  6. Hey guys I recently bought a new to me 2006 rmz250 that's needing rebuilt. I'm ending up having to put a head on it with all new valve train stuff also. I'm just having a hard time deciding whether I should go with titanium or stainless steel valves possibly even a mix of the two like on the Hondas. I was just hoping to hear from anybody to see there experience on this matter.
  7. So recently had the chain ball up and bend my shift shaft on my WR, and figured it was time for maintenance. Compression was on the low side (well...the really low side), so start disassembly to build a list of parts to replace that's going to need replacing and aim going to pick up an Athena 290cc kit to slap it back together. Looks like the engine eat a timing chain at some point and beat up one of the chain guides, easy enough to replace. However it also looks like it may have allowed some debris into the oil system that collected in a cam cap (easy fix with a scotch brite) and far more worrisome into the wrist pin. See images below: Question becomes how worried should I be about the small end of the rod? Is this normal wear for 4t? I'm surprised to see they are like 2t units with needle bearings. Next question pertains Valves (Can of worms I'm sure). Should I stick with the Ti valves. I'm currently looking at the Kibblewhite units as they are about $50 cheaper than the OE Yamaha units. Or should I go ahead and switch the Stainless Steel units? Intake valves look okay, but the exhaust appear to be pretty much shot.
  8. Hey guys new to the site just want some advise on what I should do. I got a wr250f 03 I put it into the shop to get it ready for roady I was having carby issues setting the float height correctly got it all done looking fresh but then I get a call saying he did a valve clearance check and he says they can't. E shimmed any more he quoted me 229 for valve kit and 93 to seat then he said he might as well put new pistons In and a few othe bits jist wanna know if it's worth the hassle of doing that or should I go for a full rebuild 1750 he quoted includes everything except for valve kit what are you thoughts
  9. Hi guys, i got a crf250r 2007 and im doing a complete valve job. Changing everything for kibblewhite valve kit. I don’t know what sort of valve that i had before in it but if i put SS kibblewhite valves, do i need to cut the seats or can i just use valve grinding compound ? Thanks!
  10. Just did a top end rebuild got it back together now has low compression. Did a leak test valves seem to be the problem so this is what I found. Check out middle intake valve. Anybody know where I go from here ? And how did this happen? The shim was stuck too
  11. So, I purchased a clean 2012 kx250f with 49.6 hours on it. Bike starts first kick and runs and idles great. It revs out and shifts through all the gears and has plenty of power. This weekend I took it down to the frame and went through the whole bike for a rebuild for peace of mind. I decided to check the valve clearance before I threw it back together, and got some weird measurements. The exhaust clearance was at .28mm on both lobes. Is there any reason that someone would set the exhaust clearance "loose" and be .06mm above the spec in the manual? My intake clearance is in spec, one at .11mm, the other at .15mm. I am bringing the .11mm up to match the .15mm at the upper end of the spec. I also plan to bring the the exhaust back down into spec, but want to make sure i'm not gonna mess something up if this was done intentionally. I know the gap tightens as the valves stretch over time, so I don't see why the gap would be above the specification. This is my first Kawi KX250F, so the valve train sounded loud in my opinion. I owned a Kawi ZX6R. This also had a loud valve train, but that was typical for this bike. It had a self adjusting cam chain tensioner, so the valves would get a little loud before it self adjusted. Let me know what you guys think before I throw the bike back together. Thanks!
  12. Hi there! I have an 86 xt350. It was blowing air and fuel into the air box. It wasnt running when i got it. I knew the guy before me had installed a new piston. I adjusted valve clearance and still was getting air and fuel in the air box. Thought maybe, timing was set to overlap instead of tdc. So i turned the crank 360 degrees and set the cams to match the timing marks on the caps and tried again. Still blowing air/fuel into air box. Took head apart. Both intake valves bent. Missing all 4 spring seats and oil seals. Now for the question. (Im new to this and learning) How do i find tdc without the head installed. I would hate to get new valves and bend them again. Can i just put the cams in with timing marks oriented with marks on the cam caps and the mark on the rotor oriented with the timing mark on the case and call it good or will i need to ensure its at tdc as opposed to overlap. In my mind it seems like i would have to ensure im at tdc. Otherwise the spark plug would be be firing at top of exhaust stroke as opposed to compression stroke. Thanks for your time!
  13. So ive got an 81 tt250 that i got, and the exhaust rocker arm was broken, so i tore into it, and the camshaft and other rocker are shithoused, the bearings are fine, so im not too worried, Ive cleaned out the motor to the best of my abilities, but now i need to find a cam shaft... (Part #99999-01446-00) i cannot find one anywhere online.... Can someone tell me what i can use instead... Help please @Nig
  14. Hi, I just bought a used KTM 525exc 2005. Sort of a beginner when it comes to dirt bike engine issues especially with a 4 stroke. The bike runs and rides okay but I have trouble starting it as it just has way too much compression, and some times I even feel like I'm chipping off kickstarter teeth. I'm not sure whether its the valves, decompressor, cam timing, or anything else it could possible be. Can someone please help me out as I'm really lost on what to do and local shops are quoting over $200 just to have a look!! I've tried tightening the intake and exhaust valves to see if it would make a difference and is barely noticeable.
  15. I have a 2001 yz250f and got it in pieces. It's my first 4 stroke but I've got it running, just. I'll start with the starting procedure; Turn the fuel on Choke in or out, doesn't make a difference Turn the idle knob way down Hold the decompressor level in and kick it about 5 times. Then kick it and it'll fire, then I have to hold the throttle on a bit to hear a nice idle speed while winding the idle knob up to match it. Now at idle and no choke it has a bad hanging idle if i touch the throttle. But if the choke is out there's no hanging idle. Now if it's fully warmed up i can't start it no matter what I try. Any thoughts would be awesome guys and gals.
  16. Checking and adjusting valves is considered routine maintenance on high-performance four-stroke engines used throughout the powersports industry. Valve clearance inspections are not hard to perform and are well within the capability of most owners. However, there are tips and tricks that can make the job go smoother and yield better results. The JE Pistons team has been building and testing engines for over 70 years, and as a result, we know what it takes to do the job to a high standard. With years of experience in four-stroke engines of all types, JE is no stranger to the valve adjustments and maintenance. Whether you own a dirt bike, ATV, street bike, or any other four-stroke equipped machine, chances are your owner’s manual outlines when your engine’s valve clearances should be checked. Depending on the application, the inspection interval may vary from 15 hours to 15,000 miles. Checking clearances at the specified intervals is incredibly important to ensure the engine continues to run optimally and lasts a long time. Also, as a rule of thumb, anytime the top-end of the engine is disassembled, it is best practice to check valve clearances. Any time you have the top end apart to replace the piston, you should check your valve clearance and adjust as necessary. Before servicing your engine, you will need your machine’s factory service manual. The service manual is required because it specifies the required clearances, torque specs, and other information imperative to performing the task. The outline we’re providing should be considered supplemental to the information in your service manual and is in no way a comprehensive substitute. To tackle this job, you’ll typically need the following tools and supplies: Lash/feeler gauges Metric wrenches Metric sockets Clean rags or towels Screwdrivers Caliper In most cases, specialty tools aren’t utilized, however, if they are, you’ll find that information in your service manual. A critical tool to measuring valve clearance is a set of feeler gauges. Since the engine is going to be partially opened up and exposed, it is best to work on a clean machine. If your machine is dirty, take the time to clean it thoroughly so the risk of contaminating the engine with debris is lessened. Prioritize cleaning the cylinder head cover and surrounding area. Chances are you're not working on a new bike, so be sure the area around the cam cover is clean to avoid unwanted debris. We’ll begin outlining the procedure with the removal of the cylinder head cover. You’ll likely need to remove your seat, fuel tank and various other components before this. These items should be easy to remove, and your service manual should provide sufficient guidance. When removing the cylinder head cover, be extremely careful not to allow dirt to fall into the cylinder head. If you're working on an engine still in the bike, you'll need to remove your seat and tank, along with any other components hindering your access to the cam cover. Next, the valvetrain will need to be positioned so that the clearances can be checked. Most service manuals specify setting the valvetrain so that the piston is at top dead center (TDC) on the compression stroke. Setting the valvetrain at this position ensures that the cam, or cams, are on their base circles and that neither the intake or exhaust valves are open. The base circle of the cam is the circular portion of the cam which does not influence valve lift. As an aside and for future reference, while it is sensible to follow the service manuals recommendations on setting the piston position and engine stroke when the engine is assembled, it is not necessary, especially when working on an engine that is being rebuilt. Checking valve clearance can also be accomplished with the cylinder head removed from the engine and positioning the cam lobes opposite the lifter buckets to ensure the clearance measurements are taken with the cam on its base circle. Whether the head is still on the engine or you're working on it separately, be sure the engine is either at TDC or the cam lobes are resting somewhere on their base circle and not applying pressure to the buckets like they would when opening valves. Your service manual outlines the required procedure to set the engine on its compression stroke at TDC. Most engines have mating alignment marks on the crankshaft and engine case as well as the cam gear and cylinder head. It is imperative that you know and understand how to utilize these reference points because they are used to correctly set the cam timing after any valve clearance adjustments have been made. Once you’ve positioned the cams correctly, valve clearance measurements can be made using lash (feeler) gauges. Lash gauge measurements can be tricky due to surrounding geometry and inexperience on the user’s part. To obtain the most accurate measurement, it is essential that the lash gauge is inserted between the cam and lifter bucket as close to parallel as possible. To facilitate parallel entry, bend the lash gauges as necessary so that their tips can easily slide between the cam and lifter bucket. Measure valve clearance by inserting your lash gauge(s) between the cam lobe and lifter bucket. Accurate lash gauge measurements are subjective because they are based on feel. Ideally, the most accurate valve clearance measurements are obtained when the lash gauge passes between the cam and lifter bucket with a slight drag. Gauges that pass through easily or must be forced through should be considered too thin or too thick, respectively. When this occurs, other gauges should be tried, or, if you’re between sizes, the average of the two should be utilized as the valve clearance. Begin by the using the gauge equal to the median recommended valve clearance measurement in your manual. You may have to move up or down a couple sizes until you find the size that slides between the cam lobe and bucket with a slight drag. Record this measurement for each valve. After each of the intake and exhaust valve clearances has been recorded, they should be compared to the service specifications outlined in your service manual. If the valve clearances fall within the manufacturer’s recommended range, no further work is required. However, if the clearances are outside of the specifications, determining what adjustments need to be made is the next step. To do this, unless the current valve shim thicknesses are known, the cylinder head will have to be disassembled so that the shims can be removed and measured. Follow the necessary procedures outlined in your service manual to slacken the cam chain, remove the cam cap, cams, and lifter buckets. When removing the cam cap, be sure to follow any recommended removal/tensioning sequences. Once the cam chain is free, use a piece of wire to secure it to the cylinder head. If it happens to fall in the chaincase, a pen magnet can be used to fish it out. Be sure to slacken the cam chain before attempting removal. Remove the camshaft(s) and secure the cam chain so it doesn't fall in the cases. To remove the lifter buckets, a pen magnet or valve lapping tool are both excellent aids to utilize. When extracting the lifter buckets from their bores, be very careful and keep tabs on whether or not the valve shim sticks to the underside of the bucket. Oil underneath the lifter buckets makes sticking shims a common occurrence. Use a pen magnet or lapping tool to remove the buckets. Be careful of shims that may stick on the underside of buckets. Through engine operation, the lifter buckets mate to their respective bores so they should never be mixed around. To help keep track of things, draw out a simple cylinder head diagram on a piece of paper so that the lifter buckets and all the measurements can be tracked. Proceed to remove any remaining valve shims from the cylinder head. Once the valve shims have been removed, measure the shim thicknesses and the diameter of shims used. Drawing a simple diagram can help you keep track of what buckets and shims came from where. Once everything is removed, confirm your shim measurements. To determine what valve shim adjustments should be made, a simple formula is used: New Shim Thickness = Recorded Clearance - Specified Clearance + Old Shim Thickness Calculate the necessary new shim thicknesses for all the clearances that are out of spec. Valve shims are available from most OEMs, but helpful shim kits that come with an assortment of sizes are also available from the aftermarket. Before sourcing shims, you’ll need to determine the diameter of the shim you need because there are a handful of different shim diameters used within the industry. Shown below are the standard shim diameters. Size (mm) 7.48 (Japanese) 9.48 (Japanese) 8.90 (KTM) 10.00 (KTM) Shim assortment kits are available from various aftermarket suppliers, just be sure you know what shim diameter your machine takes before ordering. This kit was sourced from ProX Racing Parts. When calculating what new shim thicknesses are required, it is best to target the specified clearance on the upper end of the prescribed clearance range. This is advised because valve clearances usually diminish over time. Valve shims are available in 0.025mm increments, so the shims that can be utilized will also influence the new clearances that can be achieved. Once you have the correct shims in hand, the valvetrain can be reassembled. Use engine oil to lubricate the valve shims and carefully install them. The lifter buckets should also be lubed before installation. When inserting the lifter buckets into their respective bores, ensure that the buckets bottom on the shims and at no point comes back up. If the bucket comes back up upon installation, occasionally the shim will stick to it and become displaced. The engine can quickly be severely damaged if the shim is not seated correctly between the valve stem and lifter bucket. Using engine oil and assembly lube when reassembling your shims, buckets, and cams helps prevent premature wear and also helps your shims stay in place while re-inserting buckets. Pay close attention to your service manual during installation of the cams and when setting cam timing. Double check that the crankshaft is in its correct position. If you’re working on a twin cam engine, it is best to install the camshaft that resides opposite of the chain tensioner first (typically the exhaust cam), pull the chain taught from the crankshaft, orient the cam gear correctly, and then wrap the chain around the gear. Once this is accomplished, the remaining cam can be oriented correctly and the chain wrapped around it. Double check orientation of all components and that timing has been set correctly. Be sure to use engine oil to lube the cam bearing bores upon installation. Make sure your timing marks on your crankshaft are lined up, then reinstall your cam(s). It's important to make sure the timing marks on the crankshaft and cam(s) remain lined up simultaneously when reinstalling the cam chain. Click here for a more in-depth guide to setting cam timing. When installing the cam cap, ensure the torque specs and sequences outlined in your service manual are followed. Deviations from either can cause the cam bearings to wear prematurely. Once the cams have been secured, use lash gauges to confirm the new valve clearances match the clearances that were calculated. Any deviations that are found should be carefully scrutinized because they may be indicative of calculation errors or shims that are not seated correctly. If there is a hint of a problem at this point, it is imperative that it is thoroughly understood and corrected before proceeding. Be sure to follow the correct torque sequence and specifications when re-installing cam caps. Assuming everything checks out, the cam chain can be tensioned. Follow the procedure outlined in your service manual to do so. Once the tension has been set, rotate the engine through at least four complete revolutions. Doing so will help the automatic chain tensioners to set the correct initial tension and confirm that the engine has been timed correctly. Position the piston at TDC on the compression stroke and check that all timing features on the crank and cams remain in their specified positions. Complete the job by carefully reinstalling the cylinder head cover, making sure to torque those bolts in a star sequence to recommended specs. Once the rest of the machine is buttoned up, it’s time to get back to riding! More Tech Articles from JE Pistons
  17. Can anyone confirm that this is true regarding cam timing:
  18. Nevermind
  19. Hey guys, Ive got a 2003 crf450r. I bought the thing, didnt run, replaced the entire engine, except carb and transmission. I took it out to the track a few days ago, and after a short break i went to start it and it wouldnt start. So i broke it all down again. I have spark, compression, air and fuel. So i figured its valves... nope valves are perfect. So confused, i broke into the carb. The carb is totally clean as well, but it starts pouring gas out everytime i try to start it. Needle jet? Bad float? Im lost. Thanks guys
  20. Any advice on what should be replaced while I have the top end off for a valve replacement. Will do headgasket and springs of course, anything other parts you would recommend while I'm going at it? Thanks!
  21. I have stock valves and springs with a Athena big bore kit and hot cams and a 41 fcr and Mrd exhaust. Do you think I should change my valves and springs? If so what would you recommend putting in?
  22. I've recently purchased a yzf 250 2016 model year and it has a ticking noise coming from the head, I purchased it thinking it would be the valve clearances out of specification, but after adjusting them, the sound still prevails. Just wondering whether someone has had this issue and what could be the cause for this odd sound from the engine. Thank you
  23. Hi Everyone, I have read some great threads but none seem to describe my issue so I would like some guidance if possible. The bike is 2004 KTM EXC 525. Purchased Second Hand in fair condition with about 160hrs. I have been slowly identifying and correcting a variety of issues. RecentIy I executed a valve adjustment which seems to have gone well. I rode the bike for little and all was fine. A few days later I was playing round with the idler screw and found I could get the bike to idle quite low in the rev range and left it. (I think this was a mistake, read on). So a few days past and I went to start the bike with Kick and it would not fire. (When I rode it previously after the valve adjustment it did need a healthy kick but it started fine). Now it will not kick start and to my astonishment the compression is huge. The reading I have done seems to indicate the idler screw affects the auto decompression in kicking in? My question is how to I get this back to easier starting? If i can get it going, is just a matter of increasing the idle speed job done? Or should I be checking the valves again? If I need to to valves again my understating is that the exhaust valves clearance is too much so they re not opening a little to make for easier starting. Thanks
  24. I just bought a new 2018 crf450r and I did an hour break in period on it split into 3 heat cycles like I always do. Towards the end of my break in period the valves started ticking on deceleration only. It sounds fine at idle and when accelerating. I thought it might be the chain because it loosens up after the first ride so I adjusted it and it still ticks when decelerating so I checked the valve clearances. I got 0.010 on both exhaust and 0.005 and 0.006 on the intakes. According to the owners manual they are in spec. This is my first Honda I've always been on Yamaha and Kawasaki so what do you guys think?
  25. I have a 2005 RMZ450 that I purchased not going. Turns out it had bent the exhaust valves. I have ordered new valves for 05-06 but the valve stems are smaller diameter. The VIN on the bike confirms that it is an 05. Does anyone know what year engine the original valves are for? (see pics for measurements) Not sure if the engine is not a 05 or the valves sent are labeled wrong.
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