Restoration of damaged cylinder head - Yamaha YZ-F 250 . . . part 2.

Continue from the previous part...
Hi.
This video shows - step by step - restoration of damaged
cylinder head.
Grinding - polishing - surface milling - valve seat cutting.
The cylinder head from Yamaha YZ-F 250
. . . for more interesting videos click ,, HERE "
/ @paulxchannel

[@chikotachikota3245]

concentration, meditiation and contemplation at real work. thy for sharing this.

[@victorarambulet3589]

Soy de Venezuela y admiro tu talento y tus herramienta y maquinas

[@johnkuchjr.]

every video I watch of yours, I'm just completely mind blown. the editing, the craftsmanship, and seeing how the work is completed is just mind-blowing great Great work. how long have you been doing this for.

[@rp75heavy]

Oddly satisfying to watch the repairs that are made, 🤙

[@miguelpagansr6128]

I cannot even imagine what it would cost to replace that head or if you can even find one, excellent work it’s nice to have the right tool for the job. Thanks for sharing.

[@PaulXchannel]

Thanks

[@ramiretz]

wow i love to see this fantastic work... every time its an eyecandy again... all this nice work and the machines... wonderfull

[@PaulXchannel]

Thanks

[@alessiopaganelli]

Bravo! Come sempre ottimo lavoro

[@compressor3001]

Направляющие надо менять все и такая прирезка держать не будет покажы как держыт с керосином

[@markdouglas5542]

Awesome work Paul, a true master at work

[@albertoalbanesi3749]

Hola sos un genio Saludos desde Argentina¡¡¡¡

[@Robert-rb6wz]

Paul, regarding the exhaust valve replacement on a 2022 YZ 250f, I'm considering using Pro X steel exhaust valves and matched springs and was cautioned about valve seat compatibility and stress on the timing chain from the heavier components. They will be installed in a new stock casting with seats and guides. The motor had 20 hours on it and dropped a Titanium exhaust valve. Do you have any thoughts about this modification? I enjoy your work and am training both my sons to maintain these bikes and they watch your videos with keen interest. Best regards from Alberta, Canada

[@PaulXchannel]

Using Pro X steel exhaust valves and custom springs - is fine. Thanks.

[@founddeadrepairz6433]

Do you do this kind of work for people?and if so what do you charge?

[@nathanielwinkle1955]

Nice to see you did not use grinding paste. We use to machine one degree difference between valve and seat and let them batter themselves together this is when BSA and Norton were floating around.

[@PaulXchannel]

Yes

[@pmel018]

Too true, the best cutters leave half a degree interference. No ancient grinding paste required.

[@paul-stefandutoit8990]

Out of curiosity how would the refacing of the head using a surface plate and some sand paper compare to the fly cutting? Asking as someone with no machine tools. I reckon a granite slab and the right type of sanding paper would be a good alternative?

[@rbailey225]

Not trying to be a jerk......am really intrigued by this. I see all these videos about how engine machining and milling is so precise. Super tight tolerances and all this mumbo jumbo. My question is how much does this affect engine performance? I'm sure this changes the volume and shape of the combustion chamber. Is it noticeable? Is there precise math involved? Does the milling of the head negate the subtraction of material from the combustion chamber? I think a lot of people get caught up in this precision when it really is not as critical to, say, maybe the every other weekend riders. I guess what I'm trying to say is....... usable? Yes, depending on your use? Would it take someone of advanced skill levels to notice that a less than ideal repair was made? Awesome video! This is exactly why I'm a two stroke guy. Even with moderate know how...the expense is a killer. Buy it new or spend hundreds in machining......choose your poison.

[@PaulXchannel]

Don't worry. Everything works O.K. Thanks for watching.

[@rbailey225]

@@PaulXchannel I wasn't worried.....was hoping you would be a little more specific. I feel like by reading your reply you may think I was slighting your work. Quite the opposite. I'm impressed. I have just enough know how to get my self into trouble but not enough to get out of it sometimes. Just trying get an idea of how critical some of this stuff is to the functionality of the bike. If you read repair guides and manuals everything should be as new if you want your bike to run. One could say I suffer from analysis paralysis. Fear of the unknown prevents me from just sending it.

[@PaulXchannel]

Thanks. On my channel I focus mainly on repairing damaged parts. The fixes I post are verified. Don't be afraid to go to the forest at night :)

[@glennmerriman8382]

@@rbailey225 Looked like he did not remove much metal from combustion chamber, and that would be more than compensated for by milling gasket surface. My guess is that overall compression would be higher than stock. Not a problem if using premium fuel. If pinging is noticed, just go up a grade of fuel.

[@rcole308]

Dang Paul, I wished you lived next door.......lol

[@PaulXchannel]

; )

[@joeishere500]

Someone send this guy some business !

[@FMFY-bl2bj]

Awesome work paul Just a question if i have some damged cylinder head How i can send it to you Is there any website of yours That serves such a purpose Thanks

[@aspopulvera9130]

I may have heard of 4 valves but never knew of 5

[@kamilsku4845]

hello .. have you already repaired the glass socket .. fancy to record how you do it greetings

[@hardkoren]

The before/after shots at the end show a millimeter or 2 reduction in the combustion chamber height. That will raise the compression ratio. On the other hand, are the valves sitting deeper in the head? That would get some volume back. There’s a ton of engineering that goes into designing the flow and combustion with tweaks to optimize for the chosen parameters. Changing any of that may end up with only a few HP difference or slightly shorter or longer engine life.

[@dbmail545]

Don't forget the combustion chamber material that was removed. After the engine is assembled the chamber volume can be measured and a custom thickness head gasket can be made if needed.

[@skylinefever]

Do you know how many CCs the combustion chamber should have? The damage and repairs may have changed it. I hope the right amount of milling was able to correct it.

[@PaulXchannel]

the motorcycle is already in operation

[@skylinefever]

@@PaulXchannel Excellent.

[@PaulXchannel]

Thanks

[@johnmartinez7975]

@@PaulXchannel can you upload the motorcycle running?

[@Gen_S_Marik]

Насколько просажены посадки клапанов? Как это отразится на регулировке зазоров клапанов?

[@nakawalna]

Потом, при регулировке зазора, придётся клапана подрезать.

[@chandanar364]

I have a damaged yz250 head. Can you help me to restore it? There no heads to buy here.

[@eduardoben7106]

Excelente trabajo saludos desde Argentina

[@jackcecil1012]

What do you use to remove carbon from cylinder heads?

[@PaulXchannel]

see this video kzbin.info/www/bejne/pZq4h4isbpWiaNk

[@jackrussel836]

Super, Aber das Kerzengewinde hätte auch noch nachgeschnitten werden sollen!

[@geraldlao3415]

Satisfying to watch

[@_SK.VEERA_TN_69]

Super anna 🥰

[@matthewpower1614]

Paul great work. Question: You ground down the valve seats a fair amount and so I assume given the valves will now sit deeper that translates as reduction in the shims in the buckets on the other side of the head (spring side). Did you do calculations as I again assume if you went to far you would have to reseat the inlet?

[@PaulXchannel]

It succeeded in toletancy ;)

[@chadrides914]

This is NEXT LEVEL. Your amazing. Thanks for sharing your work. Love the dirtbike content.

[@bustamantealdo]

Wish i had half your knowledge and skills. Awesome videos!

[@PaulXchannel]

Thank you very much .

[@c__TattinhNhi]

yes you have great knowledge i really admire

[@MohamedAli-hm7mf]

مرحبا انا معي دراجه كوزاكي بايو 400 4x4 ولا يوجد لدينا قطع غيار لها هل يمكنك مساعدتي المطلوب هيد بستن مع رنج بستن او ماهي الطريقه لئيجاد قطع الغيار

[@masksheurty6767]

Very very very gooood job 👏👌👍

[@ezzatluqman]

Whats the name of the 3rd buffer? the red one that looks like scotch brite. Been look em up for my rotary

[@andyserbert2771]

I’ve got 2 Yamaha 5 valve and a newer Yamaha 4 valve. All are 250cc. I am looking to have worked. Do you do this for a fee? How much?

[@lobolj53]

So how did this head get damaged? Poor fuel? Too lean? Improper maintenance? Do your customers tell you?

[@PaulXchannel]

Apparently old tired valves.

[@jordandennington2076]

If I send off my cylinder head can I have you repair it ???

[@ibizas.srac1.4]

Good job👌

[@PaulXchannel]

Thanks

[@Ayesha_hanif_786]

seat palish cuter how to make

[@megamindtvsydney3967]

Unbelievable bro . My wr400 head is damaged wish I could fix it

[@liamfanning_75]

ummm so does a squish band not matter? not worried about the hot spots you're clearly gonna get around the outside? i guess if compression is low and octane is high you might be okay but I would've just bought a new head. I'd hate to see you pulling a pitted piston out after three races

[@erichildreth7562]

Absolutely incredible work!! You were able to repair it and it is better than new!! I bet the bike runs great now!! Thanks for sharing and yes I subscribed to your channel!! :)

[@PaulXchannel]

Thanks for watching

[@kyzor-sosay6087]

Excellent video,man.Thanks for no shitty music.

[@PaulXchannel]

Thanks

[@hormasaid3339]

You must return the circle that corresponds to piston

[@edodearil8929]

nice, bravo!

[@PaulXchannel]

Thanks

[@dsphdyt9273]

Kalo head kharisma bisa ga

[@TorteTS]

Good comparison before / after refurbishing. Could you please share the brand of the valve seat cutting tool?

[@PaulXchannel]

Thanks. Chinesemoulds

[@___123n]

I’m guessing you can only do this once .. until the head his unusable..

[@boru-cnc]

Very good job!

[@PaulXchannel]

Thanks

[@raf1800]

Miss two strokes badly! Nice job though

[@250fxm3]

Magnífico 👏

[@joeishere500]

Si !

[@Adrianzx]

Ok now that I've seen part two I'm subscribing

[@dbmail545]

What caused all this? Broken timing chain? Broken connecting rod? Dropped valve?

[@PaulXchannel]

Bad timming ?

[@gitra182channel]

Good job,, 😇😇😇😇

[@PaulXchannel]

Thanks

[@gibamec7636]

Perfect

[@PaulXchannel]

Thanks for watching.

[@papovaris2076]

Can you help me bro please 🙏 with my 06 yz250f head?

[@TheSpeedy24]

Well done! What valve seat cutter did you use?

[@PaulXchannel]

I am currently testing a Chinese company.

[@marsillispeedgarage]

Please can you say the brand.

[@PaulXchannel]

chinesemoulds

[@nunesmotos351]

Um ekipamento muito nota dez

[@ericcarroll9643]

I got a 1997 Toyota Corolla that run sometimes and sometimes it will not run I put a relay fuse in it and it ran a little bit and then quit but it usually runs when it's warm outside and then when it gets cold it's not wanting to run I need help on what it can be some people telling me it's the EGR or I can be the fuel pump

[@javier.villatoro]

There are several causes, you can start by checking the battery, if it is in good condition check the spark plugs and the spark plugs wires, I have one with a 1.6l engine

[@michaelmorgan5714]

I'm very impressed but there is no closed caption

[@jasonheinrichs8200]

Nice job up until the valves, you did a half ass job with the valves, you didn't lap them in after machining the surfaces, I doubt they are sealed from just machining alone

[@PaulXchannel]

Thanks. More in future videos. Vaccum pump in action.

[@rztrzt]

How much would this job cost vs a used head off ebay?

[@mike_r4150]

Can't compare, this is hands down the best possible solution, it's as good as new vs a head you don't know the hours on.

[@Tixoxod102]

What about moving valves upper and using standart size adjusting pads?

[@PaulXchannel]

smaller pads

[@Tixoxod102]

@@PaulXchannel you mean standart small sizes or regrinded?

[@PaulXchannel]

as needed

[@enricogiacomello4212]

Great work!

[@NoName-ph9oe]

Переточил голову, нужна прокладка выше. Иначе поршень может встретиться с клапанами. Много снял или голова уже тачилась

[@mohdamirulaminamin9988]

good job

[@PaulXchannel]

Thanks

[@Giant2222]

Good bro👍

[@13hotskull]

Can I pay u to do mines ?

[@Ken89ilguerriero]

Fantastic

[@alexthebear]

Thanks 👍

[@puffdaddyfpv7046]

It doesn't show in the video bit do you test the valve sealment, and if so, how? Awesome instruments you have btw!

[@PaulXchannel]

I have a vacuum tester. I will show in future videos.

[@puffdaddyfpv7046]

@@PaulXchannel Guess I have to sub to see that video 😉

[@manuelgutierrez5201]

After the milling machine the groove water seal has gone. And now what would you do to isolate the combustion chamber?

[@Ivanesquevan]

Amazing!!!

[@pyrofalcon146]

5 valves... jeez

[@pgti6]

That engine must have ran without an air filter.

[@runar500]

4-strokes killed MX, made it too expensive for the average family.

[@rbailey225]

100% agreed. Just dropped 1200 on a head, piston, cylinder and valves for a bike that is worth $1500-2000. And that was just parts. Labor would have made it closer to 2000. My other two kids went the 125 two stoke route and they love it. $350 gets a re-plate, piston and rings. That price hasn't changed much in 15-20 years. Top union scale in my line of work has doubled since I bought my first brand new bike but bike prices have more than tripled.

[@dieselgeezer18]

no they didn't. Bike manufacturers killed 2 strokes

[@SM-vq2vs]

@@dieselgeezer18 luckily ktm still makes 2strokes

[@jaspervandongen6079]

What type off machine you us for valve seat cuting

[@PaulXchannel]

Own production. I will present in future videos.

[@jaspervandongen6079]

@@PaulXchannel i have the same tools but us a serdi 4.0. great machine

[@PaulXchannel]

👍 I'd like to see your machine.

[@jaspervandongen6079]

Do you also us beryllium valve seats?

[@PaulXchannel]

Not yet but I would like to.

[@zsombormata8105]

hey, what kind of valve seat cutter are u using? thanks

[@PaulXchannel]

made in Paul X workshop

[@zsombormata8105]

@@PaulXchannel sweet

[@PaulXchannel]

I will present in future videos

[@pmel018]

It has a hint of the Serdi machine to it. Nice work

[@PaulXchannel]

Thanks.

[@javasoldier5926]

magnificent

[@СемёнБогун-ъ6п]

After cutting valve seats valves go deeper in head?

[@PaulXchannel]

of course

[@СемёнБогун-ъ6п]

And now you need to make valves shorter, or use thinner washer?

[@PaulXchannel]

Yes

[@СемёнБогун-ъ6п]

@@PaulXchannel thanks)

[@glennmerriman8382]

I was worried about that too. Yamaha's already start with a fairly thin shim, usually around 1.80 - 1.90mm from factory. Thinnest shim that can be used in them is usually a 1.20mm, any less & cam follower starts resting on valve spring retainer instead of shim. So only about 0.6 - 0.7mm to play with. Although it may have looked like he cut allot off the seats, it was probably very minimal.

[@CBR_KAJI]

Part 3

[@robboape8532]

Smeriglio sede valvole no? :-/ sarebbe stato bello vederlo

[@Borkybn]

Con le valvole in titanio?????

[@robboape8532]

Da fabbrica no, da revisione totale è cosa buona e giusta

[@Borkybn]

Che io sappia le valvole in titanio non si smerigliano perché perdono il trattamento superficiale

[@robboape8532]

@@Borkybn e che trattamento c'è sul fungo delle valvole in titanio?

[@Borkybn]

@@robboape8532 con smeriglio si rimuove lo strato superficiale di ossido di titanio che conferisce la resistenza. Informati e vedrai che è come dico io

[@paat4199]

What tool at 5:07??

[@PaulXchannel]

Bubble level

[@paat4199]

Is that custom made??

[@PaulXchannel]

in my workshop

[@denisb8570]

What year

[@PaulXchannel]

Approx 2004

[@kkkkjjjlj4805]

Nicee

[@akros-8088]

broo that engine gained more HP

[@cheba4786]

🔥🔥🔥

[@Pushyhog]

this guy dont play, quit school because of recess.

[@викторгончаров-я4л]

А притерать?

[@EXTASYRO]

where are you from ?

[@casadamoto9795]

Show

[@محمدالعبودي-ش5ف]

5 ولفات

[@nonenone1249]

you forgot to lap them in..

[@PaulXchannel]

They cannot be lapped after machining the valve seats.

[@glennmerriman8382]

@@PaulXchannel Perhaps you mean that they do not not need lapping after precision valve cutting? The original Titanium valves should not be lapped, but the ones you used were steel valves, which possibly could be lapped. Unless the black coating on them is something special which you did not want to remove with lapping?

[@PaulXchannel]

The only difference between a titanium and an iron valve is in weight. The accuracy is the same. There is no need to lap when cutting the seats on the machine. Only after hand cutting!!!

[@glennmerriman8382]

@@PaulXchannel Yes the iron valves are heavier, which is why they supply stronger springs in the kit. I have hand cut seats before using Neway carbide cutters, and agree the finish is a little rough, so I had to lap them after with fine paste. Yes I suspected the machining left a much smoother surface that did not require lapping.

[@PaulXchannel]

@@glennmerriman8382 In 1 month I will present on my channel a valve seat machine made in my workshop. Wait for this video - maybe it will inspire you.

[@bezsobsaki]

Кто смеялся?

[@aaronbright5028]

Didn’t even hone the guides or lap the valves

[@berlnberln5289]

You can't lap a Titanium valves, it would remove de chrome coating and destroy the valve

[@aaronbright5028]

@@berlnberln5289 pro x doesnt make ti valves do they? Those are steel right. Just checked the label on the box and they are in fact steel. My apologies about the guide comment i didnt see that there was a video of you making them

[@berlnberln5289]

@@aaronbright5028 you are right, the black head of the valve and the fact that it comes with a spring should have maked me tik. Anyway, after a milling job it should be sealing, right away, like Titanium valve does, maybe it has been checked with some gas in the intake and exhaust.

[@ThatRandomMan1]

You never lapped the valves, you could've done a way better job

[@PaulXchannel]

You don't have to lap after machine cutting of the seats! Only after manual cutting.

[@ThatRandomMan1]

@@PaulXchannel lapping gets out all the inperfections the machine couldn't though.

[@daos3300]

@@ThatRandomMan1 you're not listening

[@pmel018]

Yes, definitely no lapping required, a quick way to ruin precision cut seats. Seats and valves vacuum tested before final assembly.

[@gusttavodias2962]

Show