How to install a big bore kit GY6 171cc / 172cc (61mm). EVERYTHING YOU NEED TO KNOW!

BUY THIS 171cc KIT:
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BUY OUR COMPLETE 61MM BIG BORE KIT:
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BORE TOOL:
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ENGINE WORK STAND:
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Valve lash .004-.005
If you are a newby and have no idea how to install a big bore kit on your GY6. No problem. this " how to install a big bore kit" video will walk you through the entire thing. No special tools needed! If you find this video helpful and want to support us please join our patrion page!

[@freestyleskyline]

I love how straight forward this is. I think I'm going to be buying a lot more scooters so I can teach my kid and learn myself

[@juliodiaz4493]

Man and you look, you can look at it all you want at the end of the day. You gotta do it yourself.

[@stevebiggs1822]

I don’t even have a gy6 engine but still found it fascinating

[@RollingWrench]

P E R F E C T !

[@marvinmatsane7629]

It is better you don't have the gy6 engine while I don't even have a ruckus at all but I still find it interesting 😀

[@EsefDubs]

Same, but I’m tryna get one as soon as I have a garage

[@oldwortex5818]

Thank you. Our 150 is just tired of the abuse my son did on it, so instead of buying a new engine, I decided to rebuild with a big bore kit. This is the exactly the video I was looking for. I will add the performance cam, larger carb (28mm or 30mm) and i hope this thing will fly :-)

[@ElPatronGamefarm]

Have you done the build yet?

[@FranklinHicks-qs4gs]

How'd the build turn out

[@SippiDeals]

How did it turn out?

[@synoptic1047]

Thanks for this like big time. I can’t find anyone to do my work, so I must learn.

[@yewwtooob]

25:25 setting valve lash. You go on the bottom side (.004 to .005 and you pick .004) . Only thing is that as valve and seat wear( in a hot combustion chamber) the oil splashed cam and rockers wear less. This almost always ends up in valves that don't seat completely, which is accelerated by valve erosion and ALWAYS pronounced on the exhaust valve due to coefficient of thermal expansion differences based on heat/cooling cycles. Exhaust valve is only cooled from oil and seated contact (heat transfer). Intake is cooled by both those but mainly by cold fuel intake (reason carbs "ice up" is evaporation) in relation to relevant heat within the combustion chamber. If in doubt, ALWAYS set valve lash loose. Especially on the exhaust. They Will wear in and close the gap, so to speak.

[@lienchen12]

This is a really good tutorial because you have a clear and step by step tutorial, I subcribe! Hit the bell and thumbs up..thank you

[@basmu7067]

Just put a Mikuni carb in but popped the head gasket in the process when starting it up, ordering y’all drop in kit Friday I’m hyped

[@RollingWrench]

Hell yaaa! You will love it!!

[@FreakinKatGaming]

Like seriously, I'm a mazdaspeed 3 owner, lost my engine... wel actually my car was stolen not long ago, anyways, over the years of learning about my engine, seeing this video I swear is like perfect for people who want to know a how their engines work and get an idea what pistons are like and how to work them as well as well long story short this videos good for anyone interested in their engines! Extremely versatile video just instead of 1 piston just add your piston count and rinse and repeat the process and just like the rings, 1 is 1 way the next one is opposite and so on and so forth, it's like a seesaw one up one down

[@s0972821]

I am a Taiwanese. I just installed a 61mm cylinder on my 26year old 125cc GY6 scooter. It becomes young again！

[@RollingWrench]

Perfect! Did you use Taida?

[@youtubeuniversity6589]

I love love love the gy6 out of all the engines to tear down to every last bolt the gy6 comes apart so nice and goes back nice easy to work on bullet proof and many many mods I love rolling wrench

[@ab_customz_llc]

As many others have already stated, great job! I just had to jump on the long list of others that appreciate your great content! Sub'd

[@deenie57]

C500cc mopead

[@171169alex]

Friend, I congratulate you, good video you explain everything very well, few videos of such good quality you can find and your video is the best I've seen in terms of mechanics, I have a buggy with 150 cc engine. By making this modification do you know how many hp I can increase? And finally, if I make this modification, will I have to change something in the carburetor? and you recommend some spark plug coil with more voltage? There will be a high voltage coil on the market for this 150 cc engine.? Thank you very much and again I congratulate you for your video, in fact you explain very well and the quality in hd is very well appreciated all the details. Greetings.

[@forevercomputing]

every engine is different.

[@stayinpositiveabiy5527]

Definitely

[@seishiro7000]

Have some experiene with motors but man , still learned someting new, great tutorial, thx!

[@brodjohn5993]

Because of your fully explanation I subscribed thank you hope more video regarding rebuild of GY6 150 motors

[@stuartcairns427]

Spot on vid m8 deffo the best one I’ve seen and thanks for the info was just about to fit my m8s big bore 👍🏻

[@ipaddy]

this is the perfect how to video for the GY6 motor I have just done this build with a 180cc motor 63mm piston looks just the same except over here in the UK on our scomadi version of the Gy6 out motor hanging mounts are underneath compared to your top version and we have a disk back brake

[@MrJoe11young]

Great video! I just bought a Hammerhead buggy with the 150cc GY6. Thanks for the info.

[@SlowStang951]

Did you ever do the upgrade?

[@coltansmoak6977]

you should make some videos about 200cc or 250cc or 300cc mopeds/scooters

[@antonionavas825]

Thanks for the great video, lots of detail and well explain. I'm replacing the cylinder head on an old Lance Venice inherited from a friend and discover the old piston lost some fragments into the crank case. Any suggestions on how to clean this out or make sure there is nothing left inside that may create a problem ? Also I have no specs regarding nuts torque. what would you advice. Thanks!

[@PaumotoRacing]

AWESOME TUTORIAL !!! From Philippines

[@loydonnrodriguez5275]

tara mga nka 150/pwede pla hanggang 171 panu kaya intake at exaust pwede parin kaya stock carb at pipe?

[@MarjanSpasevski]

0.04 is to tight clearance for air cooled engine, u need to put 0.10,when its get to working temp, tht clearance is 0.05, and u nvr gonna burn your valves,just my opinion, cause i have 170 cc gy5,157qmj block and its going 115kph tht would be 71 miles per hour btw good tutorial

[@RollingWrench]

I appreciate the support 🙏. All the details in this video is what’s worked best for me in my 18 years of experience.🤘🏻👍🏻

[@jacobdenham4800]

Just purchased the 171big bore just and two valve performance head, also throwing in the A9 cam can't wait to see my scoot fly

[@RollingWrench]

Heck ya dude!!! That will wake it up for sure!!!! Thanks for the support 🙏

[@jacobdenham4800]

@@RollingWrench anytime great content and services going to do a custom build on a Chinese scooter a naked frame with custom mounts for everything all plastics are being removed now!

[@joolsfreeman4359]

Excellent clear and concise instruction, well done, i can tackle my gy6 top end rebuild with much more confidence, thankyou.

[@ariesclark3272]

i know Im randomly asking but does anybody know a method to log back into an instagram account? I was dumb lost the login password. I love any tricks you can give me!

[@gibsoncurtis8815]

@Aries Clark instablaster :)

[@ariesclark3272]

@Gibson Curtis i really appreciate your reply. I got to the site thru google and I'm trying it out atm. I see it takes quite some time so I will reply here later when my account password hopefully is recovered.

[@ariesclark3272]

@Gibson Curtis it did the trick and I actually got access to my account again. I am so happy:D Thanks so much, you saved my account!

[@gibsoncurtis8815]

@Aries Clark Happy to help :)

[@thishereaveragelife7325]

You made a boring tool for a drill!?!? That's so cool

[@coltansmoak6977]

you have some great build videos though. tons of good information.

[@staggerarm3591]

Need this guy in the uk 🇬🇧

[@jmac7272]

That was the single greatest tutorial video I have ever seen. Can you do my gy6 atk 150c buggy tao tao? To slow

[@RollingWrench]

Thanks man! Ya you can do a big bore kit on that

[@frankryan6405]

Great vid mate you explain everything thing in detail. It looks like you don't need to re jet the carb is that right?

[@shaunaromine3709]

And the black hose at the top of the cover? You touched it and moved it a few times, but nothing about what it is for or where it goes. Would you mind explaining that one?

[@psychouki]

So you can use a 150cc head on a 171cc cylinder?? Reason I ask if because I've stripped out my spark plug hole and I'm trying to helicoil it now but I would much rather replace head in the end.

[@4204-m3z]

I recently bought a 2020 150cc ice bear q6 trike, don't know nothing about this Brand n I cant find no reviews about it. Are they any good? Are they able to keep up hours of stop n go n Long drive as well? Can I upgrade modified it? What issues do I need to look out for, what to I need to replace if anything. Any info will b great plus I'm a 300 lbs dude any help will work plus I'm new to this world of scooters.

[@wilhelmvo6399]

I just got a 4 seat go-kart for my kids that need motor/electrical work it has a gy6/clone I'm going to build it now

[@panchobello7408]

Hello. great and detailed video. Can you please leave the link to buy the long gy6 engine with the 171cc kit and carburetor already installed, that is, ready and tested to mount on my scooter, just make the connections and start?

[@littlereptilian7580]

Nice to work with new engines

[@SergioTerol]

You make it look very simple. Im saving up for a second bike, it will be a gy6 scooter. In the meantime i wanted to ask, would your EFI plug and play kit work on a geared bike? It has a 26mm intake is a 125cc... but what i am worried about is: will the EFI handle the constant changes in the throttle or is it made specially for scooters where you dont play that much with the throttle?

[@RollingWrench]

Thanks for watching. Our efi kit will work in any bike up to 1000cc. We do have DIY EFI kit out now :-) www.rollingwrenchdenver.com/products/diy-rolling-wrench-fuel-injection-kit

[@smoothjay1979]

Hey my friend. My neighbor gifted my family his old go kart dune buggy. It was sitting in his back yard for 5 years or better. Everything was full of dirt. I decided to tear it completely down. The kart was made in Korea. It has a gy6 125cc in it. I need everything. Seals, gaskets, bearings, piston, rings, valves. I have a few things ordered. But I want to be sure I ordered the correct parts. And help would be much appreciated.

[@fitzgeraldbernardbarnettcl7484]

Hai, you are very expert about scooter especially, i need a tips from you, i have a modenas elit 150 scooter, how to make it powerful than nw?... What do i need to change to?

[@caambata]

would there be a change with the carb or jettings using 61mm block? I heard you can run stock 150cc carb upto 59mm block only. beyond that, jettings should be changed.

[@coolrob1970]

Love your videos, new to the scooter world. Considering purchasing a maddog trike because I'm a big guy. Have you had any experience with this bike. Thanks in advance.

[@tootightconcepts747]

Robert Perdue well I just purchased a maddog trike 50cc haven’t got to ride it yet because of the weather but so far but I’ve noticed that it runs great in the day time but won’t run at night it might be my altitude I’m 2600 feet above sea level got some work to do on a brand new bike

[@rockydog3106]

Thanks for putting up some great diy videos 👍 how can you tell if you have an A or a B case without opening it?

[@NCYSTORE]

You can tell by the engine model number engrave on the lower part of the crankcase near the side oil drain bolt. If it says 125QMI", "157QMJ", "1P57QMJ" those are 54mm stud spacing A block (case). If it says "161QMK", "161QML" you guess it those are B Block 57mm stud spacing.

[@CannondaleF700]

NCY STORE what about p152qmi or the 153qmi KDU engine

[@NCYSTORE]

fishsticks A-block is considered 54mm stud spacing normally 125cc "QMI" , 150cc "QMJ" and both can upgrade upto 171cc engine without boring. Now, B-Block is considered 57mm stud spacing commonly use for 180cc upto 232cc engine if you want to know how to decipher more gy6 engine code checkout ncystore.com/blog/gy6-engine-code

[@CannondaleF700]

NCY STORE So you reckon my p152qmi engine I can fit the 170cc kit without boring case? But those cheap china $40 170CC won't fit because of the jugs walls? But you kit does? Right?

[@NCYSTORE]

fishsticks yes, NCY and Taida are only one that makes the bolt-on bore kit. What makes it a bolt-on is there cylinder skirt aka sleeve diameter is less than 63mm closer to 62.7mm or 62.9mm diameter to be able to slide in most A-case bore opening on crankcase is 63mm opening and Rolling Wrench should have them.

[@e_s.0848]

Are you getting 170cc or do you start with 170cc before the upgrade? I've got a 169cc and don't know what to do.

[@chrisatwork87]

Very good Informations :-) i install a 160ccm on my Kymco super 8 GY6... greets from germany...

[@serkanturunc6721]

Hi, which the Best camshaft for 58.5mm cylinder kit? A9 or a12? Thanks

[@Tapsr]

Also on the piston should I order cast or forged? Thank you for all info

[@Yakplanet_tv]

Hey with my cam lobes facing down. @22:07. My rocker arms HAS A LOT IF PLAY ROOM. SO I FLIPPED THEM. because I couldn't adjust the dowls on the valve. I have bug bore kit. With a-9. Cam. If I try to adjust the valve there's still like 1-1/2mm of play.

[@mohamadnurhassanrazalikami5178]

I got 125cc and try to upgrade to 150cc. But the piston shaft size is bigger. And i wonder do the piston shaft size are different at any level of upgrade?

[@yewwtooob]

19:00 to 19:11 true. But the reason is because the case is cut out. So he is saying if the alignment pins don't push in, they are in the wrong holes. Gasket is diagonally cut also for them. It only fits one way.

[@jimsy5530]

I've always wondered what the little rubber hoses hanging off the little modified 125cc scooters in Taiwan were: your breather tube just answered my curiosity!

[@tebibyte2357]

U mean under the carb? If so that is the overflow valve, gas May leak out if it if gas is overflowing into the carburetor. It's a safety feature so ur carb isn't destroyed.

[@imaginewagons1060]

My friend has a gy6 with the EGR tube, but my motor is also gy6 with no EGR valve what’s the difference in our motors? And can I use this big bore kit on mine with no EGR up front? Helllllp

[@donpoole8617]

Outstanding! Step by step.

[@dagobertoarburola635]

Is it good performance just by changing the cylinder? Isn't it necessary to change the carb too?

[@jasandoval7734]

Desde colombia te mando un abrazo aunque no entiendo tu idioma entendí el tutorial a la perfección muy bien explicado te felicito Muy bueno

[@protofreak9518]

Where did you get the crankcase breather/dipstick combo you don’t sell them just breathers

[@awesomebrian4835]

The oil breather u have look like it have a dipstick with it too do you seek that whole thing exactly like the one on the video ??

[@Mr.Run-n-Gun]

Nice tutorial. Very helpful.

[@PakmanR3]

awesome video man, thanks for putting this up.

[@edwinator46]

I plan to convert from 125cc to this. Do I need bigger exhaust? And what about carb? Bigger jets?

[@cn9936]

Hi there, I’m installing this kit in my gy6 soon. Do you recommend the gasket sealant sprays? Thanks

[@Nethrolloras]

does the 171cc kit require that we bore out the bottom end? or is it just a bolt on?

[@jacobdenham4800]

Bolt on

[@JamNJ1985]

Is there a way to get more power out of the stock ruckus without adding a gy6. I know a lot of people like the stretched look but I prefer the stock length of the rear.

[@richardwhitaker4148]

I usually set the piston inside of the cylinder first as a lil assembly then install the dowel and clip that way I don't have to wrestle with the piston rings.

[@RollingWrench]

That's anther way to do it. I find it a little bit easier to do it my way. But thanks for the mention, other people may prefer this method

[@Phil2stroke]

I do it like that its also how honda does it in the factory you dont have to worry about the ring gaps there all set from that point and its less messy oil wise oiling the piston between these stuts is messy

[@psyolent.]

awesome build video dude. super informative and detailed mate.

[@RollingWrench]

Thanks for the kind words! I appreciate the support 💯🙏🏻

[@walangmagawatv08]

hi rollingwrench, I would like to ask if all 157QMJ engines (China), will fit the 61 mm big bore kit without modifying or boring the hole for cylinder wall? thanks.

[@ragemotorsports4727]

Quick question.. I have the 157qmj motor on my buggy...what is the difference from the same motor on a scooter? Cause the item description says If installing on a buggy or sxs they don't guarantee fitment. just curious.

[@breezysmith4800]

I have a 150cc Advenger stark scooter. I want to be a lil faster and stronger... can i get this same set up fr my bike.. need to know asap

[@just4kicks950]

Hello my friend ✌ I should get a good power hike with the 171 big bore using my stock head , because the motor has less then 100 miles/ what due you recommend on carb in mm & what # cam, looking for a decent gain with dependability & pricing . Appreciate the info thank you

[@kenm.6307]

Anyone know where I can find a replacement shroud gasket/seal? I cant find one for the life of me.. any help is appreciated. Love this channel

[@jameseldridge673]

Sir, I have a Tao Tao 150. What would you charge to build one of these, with an aggressive trans?

[@yewwtooob]

One thing, brother. Around 9 minutes you show stock blue gaskets and exp lain to trim the inside with a razor. You are correct, of course, but don't let the paper based gasket clipping fall into the engine. It can sling around with the oil and end up eating up your ball bearings. 😞 don't ask me how I know, please🙄

[@MJSfoto1956]

just a hypothetical question: can the new head be installed with the engined mounted to the bike "in situ"? Or must you remove the entire engine to be successful?

[@DrLove911]

Sometimes yes and sometimes no. The fact that you ask that . Makes me think you should go ahead and remove your engine . Lol

[@cn9936]

Hello sir, I’m installing the Taida brand 61 mm big bore kit like yours and an A12 camshaft. I’m thinking of upgrading to a CVK 30mm carburetor and intake but the intake port on the head is 28mm wide. Is that ok or should I go with a 28mm carburetor? What do you recommend? Thanks

[@sweetlovetiger]

I have a atv with a type A gy6 and something stuff didn't come with it like the bolts to the air shroud and the air shroud rubber seal can I buy these things off your website? I'm planning on doing some mods but working out the program with it first I like the video

[@RollingWrench]

Yes no problem. Just click the create a parts estimate on the website

[@sweetlovetiger]

@@RollingWrench does that 171cc fit in the case of the gy6 a with out boring it out? How I found out it was the A gy6 the engine studs are closer thanks to your video I built the top part of the engine but like most guys need more power lol right now having a problem with spark worked good in the trail I got it home shut it off then nothing I replaced the CDI and nothing I got the 4 wheeler from someone that lost parts and it sit for years guess I was asking for trouble

[@hydrapond]

That's a great video. Thanks a lot. I learned to many things and feel appreciated.

[@RollingWrench]

I really appreciate the kind words 🙏🏻💯

[@topjj8283]

How can I get a phone number to get in contact with you?

[@stoneheartjp13]

Does all a cases fit the 61mm bbk without boring the case? I have a 125cc gy6 stock and planning on upgrading it to the biggest bore possible without touching the case. Most say 58.5 is the limit without boring the case. So if this kit is bolt on i will surely go with this.

[@jonatanfriberg3251]

Sir, isn't the scale regarding valve settings supposed to be in ’parts of an inch’ rather than mm? Big fan, love your videos!

[@RollingWrench]

Good catch. You are correct! Dang it! I corrected it in the description

[@joolsfreeman4359]

Depens if youve been trained in metric or imperial, its usually marked in both on the feeler gauge blade.

[@MURDERJUG_420]

I just bought a 150cc scooter. And planning on doin the 171 bore kit. Goin all out. But if I wanted to go bigger where do I contact u guys to send the motor to yall.

[@RollingWrench]

We don’t do customer work. We only sell the parts

[@Vicmot]

Can you use 125cc Gy6 cylinder head on 180cc Gy6 cylinder? Whats the intake and out take diameters? - But you just mentioned smaller cylinder head adds to compression = power output. But how about those intake and out take holes? How much they matters for power output when using the default 125 cc carburator?

[@varietystyle7537]

Now I use peugeot django qmj157 151cc .. Can this engine upgrade to 200 cc ? 😀😀

[@Smodlee]

How come I’m not getting any compression?? I gapped the rings all offset from each other and the IN mark facing the carburetor side. I can feel air coming out the exhaust port and my hand is getting sucked in on the intake but when I put my finger into the plug hole I’m not getting any compression so what am I doing wrong?

[@kachiskid]

Matt quick question, I gonna drop my 171cc today, is it still filled with 750mL of oil?

[@juliodiaz4493]

This guy could work

[@juliodiaz4493]

I'm learning from him

[@juliodiaz4493]

You gana do yourself big bord Kik

[@CodeMasterCody88]

The big broad Kirk is the next best thing. Dem thangs be haulin arse after you drain all the oil out. Less weight in the engine 🚒🆘💥😳

[@pooch83]

Is the TDC mark on your lighten flywheel as well?? I didn't even think about looking when I installed it.

[@RollingWrench]

Yes :-)

[@SBATHORGOD]

Can you tell me what my stock engine size is? So I can do big bite kit upgrade.. I have Chinese engine stock 162qmk1

[@caambata]

What's the name of the oil vent/cooler adapter(blue)? Tried looking at your website but can't find one.

[@worldmilitary8901]

Hello..61mm piston can fit original crankcase?

[@blooddogbloodwork2435]

What is the biggest bore kit that I can put on a 157QMJ 150CC GY6 without having to bore the case ? Do you sell them ?

[@Sebastian-je7lq]

Is there anything you have to do to the fuel system or to the carburetor to adjust for more fuel for this change in displacement

[@vintagetintrader1062]

It looks the same as a XR/CRF80 or 100 in head and timing chain guide design, I have been cautious of working on OHC engines and now I have completed a few, they are easy.

[@RollingWrench]

The shim type valves are a little more tricky. But they are both easy with patience.

[@SevanGuitars]

The breather on your site is much different. How do I get this setup?

[@gsppuffer]

Amazing how dry that motor is and hasn't even been test ran at the factory.You think they would at least use assembly lube

[@rdooski]

My thoughts exactly. Even a $100 harbor freight motor gets ran before it leaves and will have lube/grease in it.

[@gibbonphoto6718]

Connections

[@euroimports05]

my question to u is which big bore did install that u didnt have to bore the case ? what brand ?

[@jdsstegman]

Did you check the ring end gap?

[@Surferant666]

Hello. What is the biggest upgrade i can do on a 50cc gy6 engine without changing the conrod and big end? Thankyou

[@jod5659]

That's what I want to know too what is the biggest big boy can I can put on a gy650 also did you ever get an answer I need to know also

[@Surferant666]

@@jod5659 i think its about 110cc- a Honda Lead cyclinder head is the same i believe as a gy6

[@Surferant666]

@@jod5659 i have a Honda lead 110cc for sale apparently does 75mph. Previous owner messaged me as he had put the bigger head on. £200 for whole bike. Spares repair

[@adamtolley5739]

Hi I have a gy6 125 cc with engine number of hd 1p52qmi do I still need to measure the stud spacing or will it be the 57mm spacing and if it is the 57mm spacing can I put a 150cc top end kit on it to make it 150 cc

[@Rammstein0963.]

Question, what's the biggest I can bore a 50cc out to? Because I'd love to max out my top speed, thanks. 🙂✌️

[@RollingWrench]

This is the ticket ! www.rollingwrenchdenver.com/products/90cc-monster-big-bore-cylinder-kit

[@thaddeusowp3650]

Does the breather tube breathe or is it just a chamber to relieve pressure

[@deanweymouth7962]

I just finished putting the 155cc kit on my 150 scooter the timing is all right it'll idle fine but when I hit the throttle it bogs down and dies does that mean that I need a bigger main jet

[@RollingWrench]

Ya bigger jet for sure

[@MaDcOw1986]

Would this 61mm kit ran ok with a stock GY6 125cc cams and stock carburetor? Or do I still have to rejet the stock carburetor?

[@diversion4195]

I can't seem to find straight answers on the internet. Is there really any difference with the 171 kit over the 150? Trying to decide if it's worth the time and expense and what kind of gains.

[@RollingWrench]

Yes huge difference in power. You will gain about 20% more power.

[@MrKdr500]

You should always check ring end gap in the bore before installing them onto the piston.

[@RollingWrench]

True

[@RollingWrench]

@Kevin Stearns with most kits yes. But ours no. Here is a link: www.rollingwrenchdenver.com/products/gy6-171cc-big-bore-kit

[@ildeberto1]

To do the big bore kit... do you have to drain the oil in the motor before starting?

[@RollingWrench]

No, but it’s a good idea to add fresh oil

[@ildeberto1]

@@RollingWrench definitely!! Riding seasons over just wanted to make sure it wasn’t going to be oozing out when you do a big bore on a wet engine