Mine arrived a couple of days ago.There`s quite a few problems. 1) All 8 spark plug washers are the wrong ones.They are all horribly distorted to the point of not sealing at all. Might be worth checking yours. 2) Oil pump belt WAY too tight. It`s actually bending the water pump shaft.Needs the mounting altering. 3) You need to rotate the rotor arm relative to the inlet cam to alter the timing.Turning the cap does nothing. 4) Cams are very badly machined and also badly designed.Put a DTI on the base circle and at least on mine I`m getting a deviation of 0.45mm.!!!!!!!!!!!!!!!!!. Should be zero That`s huge considering the total valve lift is only 1.3mm . A "pointy" cam is the worst possible design for roller followers although it would be ok with flat tappets. I`m in the process of machining up 4 new cams with a lot more duration. 5) There`s a restriction in the flat plate under the carbs. Holes are too small.

around 3:10-3:20 you can see the spark jumping from the wire to the boot on the last cylinder on the left hand bank.

needs a supercharger i think

There's no accelerator pump on those carbs, so on throttle opening they go lean. Richen the mixture slightly and that should help. Not sure if the intake has two planes, but if it does, synchronization would be necessary to prevent stumbling on acceleration. Additional flywheel mass may help smooth out running at the cost of throttle response. Valve seats and seating may be poor, lapping in the valves or just more break-in will help starting and idle stability.

That's really really cool! I know you'll get it sorted out. But I'd be really upset if I spent that much on something and it had those issues right from the get go. Like that rocker jam nut... where'd it go?!

Can you perform a compression check and leakdown? Would be interesting to see if you can give it a boost. 78cc is getting into go-kart territory.

Just advancing the cap does not change timing but can induce spark scatter. The position of the hall effect sensor that burnt out in relation to crankshaft is what controls timing. kzfaq.info/get/bejne/sNaTrZqEyr-nnIU.html You could also use an adjustable electronic spark advance module.

To be 1 of 30 you’d think they’d make sure it’d Atleast run. Great video as always!

I can’t imagine how challenging it is to work on this engine’s performance. good luck JQ90. please do not put in too much valuable time trying to get it perfect…it may become a lifelong battle.

If it calls for straight 20 weight oil you might want to consider using straight 20 weight. I don't know where you would get that but 20w50 is going to behave like 50 weight oil at temperature and the manufacturer may be counting on the oil being thin at temperature to properly lubricate everything. I'm not sure what their design tolerances are but if they're expecting 20 weight and you're giving them 50 weight at temperature that could be a problem

This things going to look sick in a few months with a custom JohnnyQ90 roots supercharger running nitro methane and water injection.

Dope! But mannnn... . 3,000$ and the rocker arm was missing a nut?!!? I hope you didn't have to pay for this engine!

I'm glad you show the shortcomings with these engine kits. Quality on them has a way to go.

What you need is a programmable CDI. That way you are in control of all the ignition timings. Program yourself a nice RPM to Advance curve

Looking forward to seeing the JQ90 improvements!

Another perfect video for 2am in the morning. I love this channel ❤️

Wish the things came with carburetors that actually worked.

I'd be PISSED if that was mine. It just goes to show that QC is non existent these's day's 🤦🏻‍♂️ Who in their right mind would think "that's ready to go" when there's CRUCIAL parts missing which could of grenaded the engine!? It's ALSO leaking, with burnt out BRAND NEW parts AND it doesn't even run ??? How can you miss part's when there's ONLY 35 in total and was there a BOM? You need to strip it down to the bare block, check all the tolerances and make sure EVERYTHING'S there in the BOM. Going back to the dizzy (distributor). Your more than capable of making a new one that's adjustable with slots.

That engine would be a great fit for a lawnmower haha. Best sounding lawnmower ever

Very cool project, keen on the new video ! :)

my old man had a see-through v8 when he was a kid. Sure enjoyed this video.

I don't know if its intended, but this videos are the best ASMR for me. Makes me relax a lot.

I can’t wait to see all the improvements you make to this with your machinist skills!!! Turbos????

You should definitely check out Dennis Dempsey's videos on tuning this

I'd be interested in watching you improve this thing. Seems people have issues with the quality of theirs and it would be cool to see one that had been worked over

wow, missing a rocker arm nut, impressive

Oh my god, i can't wait to see what you build to put this in

That thing is awesome. Glad the missing nut at 4:03 is missing-missing and wasn’t just floating around

hey! good video. At minute 3:07 you can see the fourth cylinder that loses spark, it has a leak. Also when the accelerator does not respond, you have to adjust the screw on the side of the carburetor until it improves, that is the mixture. lucky!

Your really good at working on these mini v8 s thanks for sharing god bless

Impressive looking ! ; I hope it ends up running as good as it looks ✨✨

Keep these contents coming!

Not sure if you followed the development of this motor but I can almost guarantee if you run it on gas with a 2 stroke premix it will run great it was specifically designed and developed with gas in mind. mine runs perfect unfortunately I did have the same loose rockers and hall sensor issues but other than that it's a fantastic engine

It would probably be less powerful than stock, but man I'd love to see one of these things in a Primal Raminator (with a blower!)

Johnny I would love to see your full engine collection

Really like this channel. Only thing these tiny V8s are missing is the creamy bassy soundtrack of their bigger brothers.

It's really unfortunate that they build such a beautiful looking mini v8 but don't bother putting the same effort in for the performance and reliability. Hopefully JohnyQ can come up with a couple resolves!

Wassup! Make a NASCAR with a 4 speed gearbox or a tow truck with selectable 4x4 and with high and low range. Just giving ideas!

Hey, man, been a fan for a long time, love you're creativity. How come you haven't gotten into stroking them out, maybe some cams, you make about every other part, and remarkably, as well. Have a good one,man

I foresee much refinement and tinkering in the future.

i can see the single 16mm bike carburator coming soon!!! and a question why not make an electric supercharger? brushless with esc etc?

He’s slowly moving up to building himself an actual daily driver car 😂

A big turbo made by you on it, that thing would sound sick👍

You should try the supercharger mod on it just like you tried to do with the other v8 model. Keep up the work love the content!

Who else likes it better when Johnny made his own stuff?

Cool video brother! Try opening the high end screws a half turn out I had to do that to mine,

Hi great vid, wish you future success excited to see your creation. Have you tried NOS on these motors? Have fun & take care

Dennis Dempsey has had a couple vids up ,he's got his screaming, can't wait for next video n see what u do with yours

Terrific video! Thank you!

Sounds like the perfect candidate for a speeduino ECU to control spark.

So glad JohnnyQ shows us these oddities, I doubt most of us would ever know these things exist since we're probably not willing to spend thousands of dollars on these engines that have no real application.

That would look great in a remote controlled, car, truck, boat, etc!

It actually has a small starter. Thats awesome

What a real nice job

Cool motor at that size accelerator pumps might be helpful

Are the spark wires damaged? It looks like there was some arcing between the rearmost cylinder on the left and the bundle of spark wires.

Very great sound 👍🏻

fuel is also used for cooling or what is that return line for ?

Turning the distributor cap won't change the timing. You need to turn the distributor body with the points or timing pickup.

This video is great I have an idea u should try making an actual clutch just small for the engines size and connecting it to the transmission u built and Dyno testing it once u get the correct fixings of the engine

Soon we will be seeing you build a 1:1 scale 👌

Needs a cabin, wheels and some nice spoiler Lit engine! Starts to sound good too

That little thing is an absolute work of art. I'm curious if you could put something like that on a Dino and see how much horsepower it makes.

I love watching this channel

awesome.....i know what i'm buying myself for my birthday!!

Holy, that thing is huge.

That needs to go on a mini bike!!

definitely needs either a centrifugal supercharger or a single VZ21/RHB31 turbo and some throttle body injection/EFI, maybe you could create billet steel rods or pistons to test boost pressure

Noticed in the video- may or may not be an issue with ignition, but at around 3:09 if you look at the left-most spark plug you can see the spark plug wires arcing to the side of the block. This loss of electricity can lead to misfiring spark plugs :)

Dual turbos with titanium intake and exhaust... Now that would be sick

Will it drive a go-cart? That would be so sweet!

Whats the spark timing set at? Throttle response seems like a temp, carb, timing combo.

Johnny what do you plan on putting this beast into or using it for?

Soon the price of those engines will be more expensive that a full size v8

my 30cc 4 stroke weedeater uses one of those carbs, you might try some bigger carbs or drilling the jets in the ones it came with

Did your order it like this or built it?

Wow. Awesome

It would be cool if it had a nitrous kit for it your videos are great

Yeah That engine is gonna need to have some work and tuning to do

Man this would look cool in a top fuel dragster body

there's another KZfaqr who has one of those engines and he's got his ripping - I can't think of his name but he's a hefty guy with gray hair and stubble, his videos might help - looks like an awesome little engine and I hope it treats you well.

If one could figure up equal length headers I'm sure it would help out on the carb sink as well and would get better throttle response. Just a thought

What a beast .. 👍👍

Those carbs should have a main circuit mixture adjustment screw in the center of the throttle slide. It may be covered by a push-in cap. Some versions of that carb are easy to adjust, some are made idiot proof.

Do you get these engines for free from Sterling Kit in exchange for these videos? I feel like you make a lot of what are essentially commercials for them. I miss the videos where you would modify them or make custom stuff.

Ah, finally a V8 that'll fit in my civic

I'd love to see this type of engine....in a moped :D

Sounds like a real V8

im waiting for a oily borrower to turn up and give you a hand lol

I love that this thing just had 2 weed water carbs on it lol

Moving the cap of the distributer is unlikely to alter timing as the pickup sensor related to the trigger does that.

I expected a full tear down to start

really cool

I was thinking that could fit on a custom cafe racer.

I also bought this machine there is no problem so far it's amazing you should adjust the carburetor it comes out of the factory it's not the best I noticed the igniter you use 4s battery power it's voltage is over the rated voltage of the igniter so it doesn't work properly that's something to be aware of

that would be cool in the rc monster truck

I want this to power my kayak.

I need one of these to power my toothbrush.

You do a real good job. I would like to see them in a Chevrolet or a GMC short-bed truck. Man I bet that would be sweet . 🤗

so where did the lock nut go off the rocker arm?