We broke it, wait till you see what we found 😳

Out on a weekend ride, we had a ZRX breakdown and had to be rescued. This is the autopsy we were dying to do when we got back. It’s crazy what we found! #zrx #motorcycle #race #sportbike #caferacer #engine #epicfail

[@edmundeverett2938]

Great video, James. It's always good to listen to someone who is so knowledgeable and a true expert in engine building. Many thanks for sharing this with us 😊👍

[@Whitehorze]

As a machinist, that piston is what we call "Designed to fail". Who ever thought that was a good idea has never had grease under their finger nails.

[@alanrodriguez7341]

The customer service is really good! And the cost for the information that is provided is simply like giving money away, but a customer will have peace of mind that they are in good hands financially with any Compton Motor work. Great R and D mechanics. ❤

[@johnokemah5116]

Great explanation and depth of knowledge. Exactly why I sent my ZRX to your shop. Your work is like a masterpiece of art (and raw speed and torque). The stock 1100 was a monster but now the 1224 is like a thoroughbred race horse wanting to run. Many thanks my friend.

[@user-oz1xh2qt8y]

Awesome video. Documenting the rebuild would be ace!

[@steveharper490]

Lots of great information! I like how you explain how things are supposed to work, and then break down what caused the failures or oversight on what you found. I like mechanical jargon, could listen too you for hours! Love your builds!

[@patrickgill9837]

Your the man! Im retiring at the end of the year and sending my bike to yah for a 1224…..Cant hardly wait

[@matthewharlowehrscyclespor668]

A great tutorial. The physics of internal combustion motors is an awesome subject. Thanks James

[@brianwells5258]

Thanks James....,that was great and your expertise shared is on another level... Watching with great interest every dirty secret this motor has in store as the tear down develops along the way... Have you only encountered this "issue" with their Stock bore HC pistons...and never with their 1224..? Thanks again James...,you Are the man. God bless BG

[@JamesComptonCustoms]

Thanks BG! Yep just the standard bore problem, no issues with the 1224.

[@KLL1869]

great info from the beat zrx builder

[@capt.alcummins3364]

Thanks for the insight! Was watching this video and heard the rooster..turned everything off..asked the wife had she heard it..she said no..heard a rooster crow that was NOT mister woo!.lol too funny! Life on the farm!

[@derrikmiller33]

Thanks for taking the time to make this. I love quality shop talk.

[@stevewright5818]

Great explanation of the motor and the pluses and minuses of someone else's build! And the basics of the ZRX/ Big motor architecture. Thank you!

[@gregc6661]

Glad to be running your chain tensioner lockout in my ZRX

[@JamesComptonCustoms]

Thanks for your business!

[@philhicks3390]

Thanks James. I think kawasaki should have done a recall on the tensioner. Clearly a weak point of the otherwise solid motor. My tensioner let go on my 2008 zrx1200 destroying my clutch, luckily not the whole motor. Cost was in the thousands to fix. Genuine clutch basket is $1000 dollars. Your tensioner has given me peace of mind, with now many thousands of trouble free ks. Zrx owners please purchase this mod from James because in time the tensioner spring will weaken back up and your in a world of pain.

[@arthurrodriguez6878]

Thank you James!

[@modoodle1851]

Very clear explanation . Very knowledgeable individual . Keep up the good work 👍

[@hilbilchillbil]

Great insight into potential problems thanks for sharing 👍

[@highviscosity749]

Glad you said that part about open carbs..always wondered about it. Never heard anyone speaks about that. Nice job, beautifull bikes.

[@mudnducs]

Great, detailed, video!!!

[@darylj2617]

Great video! thanks for sharing.

[@leahmunkie]

Cool! I especially liked how you drew a mental picture of the way the piston failed at the exhaust pocket. 100% on open intakes, I ran my fzr400 with FCR's for many years w/ open intakes, evan an endurance season, bores were fine. I run my norton Commando with a stack and open intake, bore is fine. If something catastrophic happens, rebuild better than before. Love this shit!! Love your work dude! You and I went thru riders school very close to the same time. CRRC

[@wolfdogg40]

Great info James

[@clifffoltz651]

Thanks for sharing your thoughts and knowledge ano less experience ! Very very interesting !❤❤😊😊

[@ArashAryana]

Thanks James! 👍🏼 Really loved the part about running unfiltered carbs.

[@YouCantSawSawdust]

You are receiving good advice here. Listen and learn. You are a lot better off taking advice from someone with James' experience, than all those DIY weekend shed mechanics on forums such as ZRXOA.

[@josephruck1]

Yes, really appreciate your detailed explanation

[@Evogixer]

James, that was a bucketful of great info, thank you very.much! Although I'm now thinking what 78mm Kawa pistons I can replace the aftermarkets I have!!! Andy Mulcahy.

[@jerryplews1023]

Very interesting video. I have a standard zrx1100 and believed the starter tension only happened when starting. Fix kit is on order from you straight away.

[@gixxer750axld]

thanks for the vid and the knowledge you share. I really dig my rex , 2nd one now, think my green one was faster ,lol. I have your tensioner ready to install as it is time to run the valve's too.

[@steveschimmel1104]

Great Video !!

[@vicpnut1]

So yeah , I can change my own oil 😂……wish I had the …..well, first the place to do this type of ,second the knowledge ,third the years of experience that would inevitably bring fourth ,the cash flow …….but seriously it’s completely obvious you KNOW what you speak of …you wouldNt happen to have an old man’s type of internship program would ya ? 😜😬..I’m stuck on my fz1 popping ignition fuses as soon as it warms up after I installed rmstator brand coils , I dont see where I did anything wrong so am assuming the coils or a coil was bad from the get go…(back to originals this weekend probably)then I see this video pop up and I’m like in awe lol…and on the most awesome standard bike imo ,zrx has always been my dream bike since first seeing one in the Kawasaki showroom back around 2003-2004. So new subscriber here , hoping maybe I’m not too old to possibly pickup on a few things from you …

[@JamesComptonCustoms]

Glad to have you here!!

[@saschakruger2201]

Thank you very much for this video. How about taking us trough the rebuild of the engine? Btw, is that a Gpz900r upper fairing in the corner?

[@dennisobrien2578]

Who makes those pistons? People need to know!

[@user-gh1cm1nl7e]

Awesome video!!! Please do more in-depth videos, also what is the 1st to 2nd gear change modification, my zrx is hard shifting in that range Thanks again!!!

[@JamesComptonCustoms]

You have to split the cases and take the gearbox out of the engine to do that one. Feel free to call if you need.

[@BB-xu8dn]

Just finished my zrx build with the stock bore hc pistons.. 😅 any idea what time they last? Or will i have to swap it out?

[@redrighthand9455]

great video

[@paulwood3867]

Very interesting info

[@anthonyambler7118]

I’ve seen a big bore kit on a SV650 do that exact thing to pistons wonder if they are the same brand

[@brookcampbell2940]

Making vids before the rooster crows. You’re a machine!

[@howardyarnold3133]

Great mechanical insite vid..ZXR 1200 engine a work of art.. Like Johnny's vintage motorcycles, always good to watch you all stripping & rebuilding 😊

[@Right-Handed_Neutrino]

What about EFI bikes with Ram Air intakes on the street? IE my 2014 ZX6R & 07 GSX-R 750 with the front screens removed @ intake entrance? I also don't ride in the rain & that's the only thing i can think of that would go inside.

[@redrighthand9455]

god damn that rooster lol :)

[@kylebowens5822]

I have been looking to buy one of these. You only make me want one more

[@JamesComptonCustoms]

Great bikes!!

[@volationlimited9214]

Hi from NZ again! Cam chain tensioners fitted to all 3 ZRX’s down here and I picked up a set of flat slides on a business trip through LA this year. Was thinking to build a track bike with them but after hearing you run stock street engines with open intakes has me thinking of fitting them now. We have a lot of salt air at times and while I agree with dust being negligible, what’s your thoughts on no filtration for salty air? This ain’t hot and dry Texas mate! Cheers, Steve

[@JamesComptonCustoms]

I wouldn't be concerned because the rings and the valves are the only parts that have any iron in them to oxidize and they should be adequately coated in fuel and oil. I don't think it would be an issue.

[@paulaus]

I thought you said 5 speed shifter then you pulled out the 5 speed shift drum and I was 😬

[@kiddcisco]

Great vid, ironically just picked up a tensioner tamer for my ZX11 last week from another custom vendor. Question, will you guys do ZX/ZZR11 engine work?

[@JamesComptonCustoms]

Yes we will

[@kiddcisco]

@@JamesComptonCustoms I just may be in touch as I wanna go deep:)

[@tcjnr82]

Could you do a full engine build video sometime?

[@JamesComptonCustoms]

I’ll see what I can do 👍🏽

[@tcjnr82]

@@JamesComptonCustoms that would be cool

[@jerrycagle7565]

Great video, question, if I put air filter pods on my 2003 zrx 1200 will I have to change the jets, also do you have that kit, thanks again.

[@JamesComptonCustoms]

We sell the filter adapters but don’t sell the filters because we haven’t found a suitable fit. And yes it restricts air flow so you’ll need a smaller main jet.

[@jerrycagle7565]

Okay I will check your website and find some, also looking for that starter chain adapter you sell.

[@JamesComptonCustoms]

jamescomptoncustoms.com/product/alternator-chain-tensioner/

[@samheninger505]

No filter probably sucked small amount of water in the motor and broke the piston, water does not compress and somthing will break, being water it left no witness marks,

[@tonyciriello6872]

Just found your channel so I don't know if you will see this comment. I always say I wish I had kept all the bikes I have owned. (55 years of riding it a fair amount) But, if I could have one back it would be my ZRX 1200R. How can it be that it has such a popular following now and Kawasaki does not see that and build a modern version. Just make it look about the same without the stupid transformer looks. DO IT NOW !!

[@julieoliver8170]

Ill keep filters just because I dont even want dust in my head and chamber. My preference only.

[@chriscarbaugh3936]

Please tell me those are not Wiseco 1109 pistons!!!

[@redrighthand9455]

EGG FARMER WTH as i like my eggs unfertilised

[@samheninger505]

Gee the top of the piston is broken off, and you say there's nothing wrong with running with no air filter. Don't you think possibly with no filter something was sucked into the motor and broke the pistion. Screw the 2hp gain ,I'll be running a filter

[@Marc_Wolfe]

You seem like the guy to ask about mismatching some parts to get a 5 speed + reverse, without having a weird gear range.

[@JamesComptonCustoms]

We’ve never done that one

[@Marc_Wolfe]

@@JamesComptonCustoms Would make a really neet cross kart. Would be made cool enough by just lathing teeth off 1st gears and replacing with sprockets and chain. One of these days I hope to acquire a very large outboard boat engine transmission for the forward/reverse and use a car diff.