Jump to content

Search the Community

Showing results for tags 'piston'.

More search options

  • Search By Tags

    Type tags separated by commas.
  • Search By Author

Content Type


  • Dirt Bikes
    • General Dirt Bike Forums
    • Make / Model Specific
    • Dirt Bike Technical Forums
    • Special Interest Forums
    • Dirt Bike Regional Discussion
  • General
    • General Forums
  • ATV / UTV
    • General ATV / UTV Forums
    • Make/Model Specific
    • ATV / UTV Regional Discussion
  • Inside TT
    • Advertise
    • Community Sponsors
    • Site Usage & Functions
    • Bug Reports & Suggestions
  • ThumperTalk Clubs FAQ & Help's FAQ/Help & Discussion
  • RokFox's Current Kit
  • RokFox's What's New
  • So Cal Flattrack's Club Forum
  • Pittsburgh Area Off-Road N@'s Welcome!
  • Walker Valley Single Track Riders's Club Forum
  • Thumperjunkies - Ottawa & Eastern Ontario Riders's Discussion
  • Jersey MX and offroad's Places you ride
  • Jersey MX and offroad's Discussion
  • Sonoma Coast Skinny Twisties's Discussion
  • Sonoma Coast Skinny Twisties's Topics
  • New Mexico Trail Riders's Discussion
  • Okanagan Off Road Motocycle Club's Club Forum
  • Redwood Riders's Club Forum
  • jack graybill's Club Photos
  • TAS trail/Enduro riders's Club Forum


  • Universal Parts & Accessories
  • Parts & Acc. - Japanese Bikes
    • Honda Parts & Accessories
    • Kawasaki Parts & Accessories
    • Suzuki Parts & Accessories
    • Yamaha Parts & Accessories
  • Parts & Acc. - Euro Bikes
    • Beta Parts & Accessories
    • Husqvarna Parts & Accessories
    • KTM Parts & Accessories
    • Other Euro Parts & Accessories
  • Motorcycles
    • Off-Road Motorcycles
    • Dual Sport Motorcycles
    • Street Motorcycles
  • Powersports Gear & Apparel

Products Categories

Vehicles Categories



There are no results to display.

There are no results to display.


  • ThumperTalk Clubs FAQ & Help's Club Calendar
  • RokFox's Enduro Ride Schedule
  • So Cal Flattrack's Club Calendar
  • So Cal Flattrack's Events
  • Walker Valley Single Track Riders's Club Calendar
  • Thumperjunkies - Ottawa & Eastern Ontario Riders's Club Calendar
  • Thumperjunkies - Ottawa & Eastern Ontario Riders's Events
  • Sonoma Coast Skinny Twisties's Calendar
  • New Mexico Trail Riders's Events
  • Okanagan Off Road Motocycle Club's Club Calendar
  • Redwood Riders's Club Calendar
  • jack graybill's Club Calendar
  • TAS trail/Enduro riders's Club Calendar

Find results in...

Find results that contain...

Date Created

  • Start


Last Updated

  • Start


Filter by number of...


  • Start





Website URL






Found 61 results

  1. So I have a 1998 Yamaha Yz80, and I need a new top end. I found a 2002-2017 Yz85 piston kit, for a very reasonable price, and I was wondering if it would be able to fit my 98 Yz80? Would the piston, wrist pin, bearings, rings, Etc be able to fit? And will it work?
  2. Dr8699


    Hey, new member here looking for opinions I have about 8k miles on my 2015 DRZ400sm. I was riding about 80mph and felt a momentary loss of power, dropped off the throttle and it felt ok. At the next stop i could here top end noise like the piston was tapping so i tore it apart and found: The upper piston ring was ok, the lower was stuck in the groove (flush with the piston ) and unable to move around the piston. there was scuffing on both intake and exhaust side of the jug and piston. Before tearing apart i did a leakdown and could hear air from exhaust and from down by the timing chain. I will try to post pic and video with this post Bike was running great then had started puffing smoke when i get on it quick, and the idle would fluctuate a good bit 2015 DRZ- 3x3, k&n filter, FCR39 (with eddie mod) DRZ E airbox boot and exhaust header with drilled out stock SM muffler with "power tip"
  3. rgleato

    Need Advice On Piston Replacement

    I was an idiot and accidentally over-tightened my spark plug on my KX450. In doing so I put a slight indention right in the center of the piston that you can see in the attached photo. I was wondering if this is enough damage to warrant me buying an entirely new piston? Or will I be okay to continue using this one?

    No carbon buildup on piston?

    K so I am getting so frustrated with this bike😕 the problem is when I looked down at my piston with a camera there was absolutely no carbon buildup on the piston and it still looks new. What could cause this? The bike is a 2001 cr80r. (Thanks)
  5. Howard94

    Which piston for 02 YZ 250

    I am rebuilding the top end on my yz250 this winter and need to know what piston to get. I am getting an oem piston and I'm unsure how to identify what piston I need. I believe there are 3 different oem pistons. Anyone know where the identifying marks are?
  6. First post...and of course I'm asking for help. Somehow my son demolished the piston on his kx85 (2009). Cylinder is slightly gouged near the exhaust port and cylinder head shows signs of overheating. Could I get by with a cylinder sleeve in this situation? If so, could I get it pressed in at a machine shop or is it better to go to a moto shop? ...Or is it better to replace the entire cylinder jug? If so, any suggestions on good brands (or brands to avoid)? I'm a 2-stroke newbie...any advice would be greatly appreciated!
  7. Zapdos

    Can I run this piston?

    Is there supposed to be a bit of resistance? Is it warped? Is the pin worn out? Can I run it without damaging the cylinder? https://streamable.com/mll5b
  8. So, I have a 1998 Yamaha yz80, and it's had a lot of hours on the top end, so it's time for a rebuild. I have a neighbor who is going to help me with it, so i havent taken it apart yet. I'm trying to figure if my bike needs a whole new piston kit, or a gasket kit, or does it need new reeds? So its lost compression. Way less then what it used to be before. The bike is really hard to start, and it fouls my plugs like none other. It doesen't have too much of a power loss, although, the powerband has become weaker. I just want my bike to be running like how it used to be, and I don't want to spend a lot of money on it. It will start sometimes, but most of the time, it will only bumpstart. I appreciate you viewing this, now, so let me know of what I need.
  9. Rainnosaurus

    2010 KX250f - won’t start, cold start

    I bought a 2010 KX250f from a guy who bought the bike brand new back in 2010 (only had 1 owner). The guy put a high compression piston in this bike. Also he was pretty much running straight race gas because when he took it to the shop, they must have messed with the jets because they weren’t stock anymore. I got new jets. Currently at...........………Pilot Jet - 42. Main Jet 185 I’ve messed with my air screw and tried a few things out but I still have to kick my bike like 30 times before it finally starts! The piston is supposed to be high compression but it doesn’t feel that way. I’m thinking of just replacing it and going back to stock??? Any thoughts? Ive read that valve clearance is an issue with this year bike... Also that Kawis need a little throttle when you kick. It ends up flooding every time. Send help please!!
  10. MotoxMike7

    2014 CRF250r Engine Mods

    Hey everyone, I'm actually new to the forum and just created my page, so hello to you all! Anyways, I have a 2014 Honda Crf250r that I purchased in December of '16 with only 34.5 hours on it. I have since ridden that bike everyday that my work schedule allows, and she now has 100 hours on her. I have noticed the bike has become a bit harder to start, taking 10-20 kicks compared to the 1 or 2 that it would originally take to start it. Once the bike hit 100 hours, I decided it was time to tear it down to the frame and open up the heart of the beast. Upon removing my stock air boot, I noticed some dirt in my throttle body. After removing my throttle body, I also noticed some dirt where the throttle body connects to the engine... Probably why my bike is getting hard to start... Now I have not opened up my engine yet, and this is where you guys come in to help, but what exactly should I replace internal wise in my engine at 100hrs? I consider myself a C or B class rider, and I stay in the upper rpm range of my bike frequently. I would like to gain a little bit more power out of my bike, specifically in the top end/over-rev area since my bike has enough bottom end already to pop wheelies in 4th if I really try. I was thinking a high compression piston, cam, and idk what else. I don't want to lose bottom end power though, and I would like these internals to be reliable too. What part recommendations do you guys have, and what are some good brands? Hotcams/Procircuit/Carillo/Wiseco/etc
  11. kevelev

    2 Stroke Piston Questions

    The bike in question is a 1999 Suzuki RM125, not sure how to tell which casting (A, B, etc.). I bought a ProX type A piston for the bike, and then afterward when I looked at the one in my bike it has a "B" on the top. When mine arrived it had an "A" (no surprise). It looks like type A has an OD of 53.94 mm and type B has an OD of 53.95 mm. I was wondering if I can run the piston I got in my bike without any issues. Would that hundredth of a millimeter really matter? Either one would be a big improvement over my old one. Also, both A and B are windowless. What exactly does that do, would the bike have more power if the piston had a window? Thanks!
  12. Diogo Silva

    250 EXC ‘06 upgrades

    Hello u guys I have to do a full service on my 2006 250 exc, it’s an eu model. I have a big big scratch on the cylinder, and I don’t want to reuse it. i’ve seen some things that I can do with it One of my wishlists it’s a 300 upgrade, and I need to know what do I need to change to a 300 convertion, and if you can tell me which other upgrades I can do with it, from newer models, like an electric starter, mapping, and other stuff, just because I don’t know if the parts of the newer models like a 2011/12/13 cylinder fits my engine. please let me know if you can help
  13. Seized my engine last weekend because i put in my oil filter one backwards... i'm a dummy. Needles to say I need a new cylinder and a new piston this is what i'm ordering or at least planning to order.. Piston : https://www.rockymountainatvmc.com/p/974/3784/Wiseco-Piston-Kit?v=533&s=47466 Cylinder: http://www.ebay.com/itm/2004-KAWASAKI-KX250F-OEM-CYLINDER-JUG-TOPEND-TOP-END-KX250-KX-250F-250-F-RMZ250/192304125998?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649 going used on the cylinder to save some money. My question is.. has anyone done one of these and if so do you have a step by step how to? or know of a video on how to do it? on a bit of a budget and want to get back riding as soon as possible. Thanks for looking!
  14. I just picked up a 93 kx 250 traded my 125 since it need a piston no problem i thought so i went to find the piston size for it but mine is a big bored at 73.8mm i just don't know where to find the new piston i was told by the owner that i could just search 73.8 mm piston and buy any one but i highly doubt that so if anyone can point me in the right direction that would be great thanks. Posted some pic below to see if it helps.
  15. So I just bought a 2017 rmz 250 and I was wondering how often I have to rebuild the top end. I figured as long as a keep the oil changed every 3 hours and a new oil filter every other oil change and keeping the air filter clean I wouldn't have to touch the top end very often but the book says every 20 hours and I don't think I can fit that in my budget so often, any opinion is appreciated, thanks.
  16. Alright, so I just got done rebuilding the top end on my 07 KX 450F and as I am getting ready to install the top of the cylinder head I notice I have one last piece remaining that I can't account for. I mark everything and take several pictures so I can make sure everything is put back together perfectly, but somehow this piece evaded me. I showed where I think it goes in one of the pictures I provided. Can someone tell me if I am right or if this piece goes somewhere completely different?
  17. Hi guys! I'm wondering if any of you know for sure if the advertised compression ratio of CP Carrillo piston for our bike is achieved with the single layer base gasket (.010" thickness) or with the standard 3 layers base gasket (.030" thickness). I'm asking this because I noticed they offer the same piston (12.5 cr) for both LTZ and DRZ but with different gasket kit, and it seems odd to me since it's the same engine.
  18. troymac1ure

    1999 KX250 Piston choice

    First off, I know that there are multiple posts on the cast/forged piston debate. I keep jumping between being firmly decided on one to the next. Here's my situation. This is the first bike I've ever owned (1999 KX250) and have ridden it for 2 seasons now. I use it for mostly trail riding with a few visits to the local track to display how much of a noob I really am. I noticed piston scoring through the exhaust port and not knowing the history of the bike I opened up my can of worms. I am at the point where my head was sent out and re-plated (due to small chips in the plating) and I found play in the crank bearing so the case is now split in half. I ordered the Hot Rods bottom end kit (CBK0055) and swapped out my input shaft and output shaft first gear with a '97 transmission as found in other threads here on TT. The crank was a wiseco, but rebuilding it was not an option anyways as some previous owner decied that the crankshaft threads on the stator side were too long and cut off all but a few threads . So now that leaves me with the decision: What piston to use? Wiseco? Vertex? Pro-X? OEM? I know that many people like the wiseco/forged pistons for longevity. People stated that the forged pistons didn't need as much clearance as in the past, etc but these posts were back from early 2010's. I am leaning towards Wiseco as I assume if anything forged has become even more versatile but my thoughts keep thinking "How likely is it to cold seize? Is it more likely to score my new cylinder than a cast?" and "If more clearance is needed for forged should I be running a cast in my recently plated (stock size) cylinder?" I just tend to over think things sometimes but the last question is the one that is bugging me. Thanks for any opinions/help. Also, is the case sealant just like a high quality silicone? I hear people mentioning HondaBond and YamaBond is good for this. Is this the same stuff you use on for grips?
  19. FloydIN

    Pistone Bore Clearance

    HI. I have CRF450r 2007. (Sorry for my inglish. I am from Georgia. Tbilisi ) thanks . I want to by Wiseco or same piston. My bike bore size is 96.03 mm (I do not know for sure. Car engine master told me). I am interesting about clearance between bore and Wiseco piston. What clearance will be between wiseco piston and my bike bore ? What size of same piston i need tu buy for my baike bore size? What is the real size of wiseco piston for crf 450r/ or maby will i buy another brand piston. When i look to my cylynder, i see good hone and it looks like new. mayby engine master is vrong about size.
  20. Stafford StJames

    2002 TTR90 piston kit

    Hi Guys, trying to get a replacement oversized piston kit +.5mm for a 2002 TTR90. The only ones i seem to be able to find from Wiesco etc are for a 2003 onwards? Does this definately not fit a 2002? Does anyone know a manufacturer that makes one for a 2002? Thanks guys, any help is most appreciated.
  21. Chiofalo11

    What could have caused this?

    Hello, my dad and I just re-did the top end on my 2014 Kx250f. We used a new cylinder with a wiseco piston and rings. Everything went smooth and had no problems putting it back together. It started right up and ran great as we let it idle for a few. Then the rpms jumped up quite a bit so we shut it down. When we went to start again it kicked over smoothly but wouldn't start. My dad brought it into the basement and kicked it over a few times and all of a sudden it wouldn't turn over at all. He said it appeared to be seized so he pulled the head cover and checked for oil circulation which was good. Today we pulled the head and cylinder and found that the upper oil ring was splintered. Now the piston, cylinder and rings are trashed. Oil circulation does not appear to be the issue and plenty assembly lube was used. Rings were also installed just as indicated in the instructions. What could have caused this to happen??? Thanks for any help, Danny
  22. Hey, new member here (been using the fourm for years) but just finally joined. I have about 8k miles on my 2015 DRZ400sm. I was riding about 80mph and felt a momentary loss of power, dropped off the throttle and it felt ok. At the next stop i could here top end noise like the piston was tapping so i tore it apart and found: The upper piston ring was ok, the lower was stuck in the groove (flush with the piston ) and unable to move around the piston. there was scuffing on both intake and exhaust side of the jug and piston. Before tearing apart i did a leakdown and could hear air from exhaust and from down by the timing chain. I will try to post pic and video with this post Bike was running great then had started puffing smoke when i get on it quick, and the idle would fluctuate a good bit 2015 DRZ- 3x3, k&n filter, FCR39 (with eddie mod) DRZ E airbox boot and exhaust header with drilled out stock SM muffler,
  23. I just ordered a piston kit for my 1998 yz80, and it does not fit into my cylinder. I can't really remember if its a 47.5 mm or 47, i'm pretty sure it's a 47.5 but it just does not fit into my cylinder. My cylinder does have a big groove in it, so do I need a new cylinder for it to fit, or a new piston? Please respond ASAP!
  24. nick andrist

    kx250 98 Kx250 Rebuild Help

    Hello everyone I want to start out with I bought the bike a couple days ago and started the year down. When I bought the bike the kick start didn't move an inch so I figured it was seized. I started the tear down of the top end and I will included pictures to show you what I found. A piece of the piston broken off. I'm not to sure what my next step is. With this happening is the crank garbage too or is it still ok. with this happening the top end is in great shape I'm just scared of the bottom end. So many questions. Thank you for replying
  25. Richardpb88

    00’ KX250 transmission help

    Putting back together a 2000 kx250 project bike I picked up a while ago after replacing the crank, bearings, and seals, etc. and have a question about the shift drum assembly and positioning. Must it be in a specific gear or neutral when putting the cases back together??? I removed everything from the case halves and want to insure that I put it back together right but can not find anything in the service manual that relates to this area and timing. PLEASE HELP!