[SparkyMJ]

Hey fellas!

Figured I'd start a thread for this, move it if needed.
My '14 N300 with 40k+ miles, a lot of commuting, hard riding, track days, and some people learning on it needs some real love and care. It runs pretty good, it shifts a little crunchy, a bit of lash has developed in the trans/clutch, oil gets dirty quite fast, slowly burns oil, idles low when cold, and sometimes has trouble starting if you don't have the magic touch.

So I set out to remedy as much as I can on my own, and hopefully someone somewhere can learn a thing or two from my mistakes.
Really, the whole bike needs love, except the brakes. I recently put on steel lines, cleaned the calipers and pistons out perfectly, and that is awesome. Here's the plan:

Engine:
-Piston rings/hone
-Cylinder, cylinder head, and valve cover gasket replacement
-Valve clearance adjustment/shimming
-new spark plugs
-water jacket cleaning (suspect buildup)
-engine exterior/sprocket area cleaning
Maintenance if a need is found:
-new pistons
-valve seats

Bike:
-new Dunlop Q3+ tire set
-new right handlebar (bent from previous owner dropping)
-AGV standard length adjustable levers
-fork oil (maybe ohlins cartridge if I can be convinced to drop the cash)
-new DID VX3(?) X ring chain
-wheel bearing cleaning + grease packing
-airbox/filter element cleaning (super dirty...)
-radiator fin straightening + clean out soak

If needed/wanted:
-fresh water hoses/clamps
-woodcraft rearsets
-exhaust header cleaning/coating
-block off plates

I may also 3D print some pieces to fill missing chunks in my fairings from previous owner drops, and then wrap over the areas, but that is for the very end.

It's not gonna be cheap, and it will take me well over a month of constant work. I've never worked this deep on a motor that wasn't broken, so that is new to me, but I think I got a good grasp on how things work and how careful I need to be.

I am already working on this project, I have recently dropped the engine, and I am working on getting the cylinder head off. Everything is just super dirty, mostly on the outside of things. So half of my job will just be degreasing and cleaning the exterior of things.

I want her fresh and ready for my last Spring track season in Arizona, and so she'll be cleaned and ready to rip for another 40k miles after I move.

Here's a picture after dropping the motor, and a lot of swearing. Lol.

Cheers, enjoy the spring riding.

-Mike

 

[iahawk]

will be eagerly awaiting your updates and pics of progress!

 

[MAL]

What is the reason for the starting difficulty, you think? Just generally tired?

What does "block off plates" mean?

What was the most annoying part so far, that required the most R rated swearing??

Kudos! Looks like a great project!

 

[JFMNINJA300]

What does "block off plates" mean?

Kudos! Looks like a great project!

Block off plate, prevents air being injected into the exhaust which causes popping in after market exhaust. There is only 1 block off plate for the 300 since it is a twin. I have a full Brock exhaust and it was popping like crazy before I had the ECU FLASHED and block off plate installed. Not a hard job, just tight spaces. I did it by removing the left fairing and I was able to get the block off plate installed. No need to removed the gas tank.

 

[SparkyMJ]

Very nice plate install. I am hoping to get away with installing the plate and running stock exhaust for now. My track org is picky about noise, and I daily ride her, so aftermarket exhaust would probably be later and the whole real deal.

Definitely literally getting the engine out was harder than I thought. Once you take out the bolts, it just kinda.... floats there. wedged in the frame. A loooot of wiggling and vigorous shaking required. That, and some of the bolts on the engine and its pieces are already impossibly tight from all those heat cycles, so that's fun.

As for the rough starting, I am not sure exactly. Rough cold starting shall I say. If its the very first start of the day, I have to let it prime all the way, and then press the starter long enough to get it to take off. If I do it right, it sounds 100% normal and starts quickly. BUT. If I don't hold the starter long enough, it'll crank, sputter, and die, and then after doing that, it is hard to start. I would then have to hold the throttle open manually when hitting the starter, and it would chug along the first couple fires real rough, then slowly let off the throttle so the cold start high-idle valve can kick back in. Maybe my spark plugs are old again, I may be overdue on them. But yeah its just that first start of the day, I have to nail it. Then once she's warm, works great. Maybe my rings are so worn that at cold temps, there is just barely enough cylinder pressure to run. I have not done a compression test to verify, just my educated guessing.

I will say too that the valves are certainly out of spec by now too. And I found that the low idling when cold (and not in 'cold start high-idle' mode) was fixed by adjusting the valves to spec last two times. So, that means I could potentially have a valve that's literally open most (if not all) the time, causing terrible compression/cylinder pressure, and thus difficulty idling. But, I am quite sure if my valves are in good shape, the clearance adjustment alone will help my compression, and then the rings and honing, once properly broken in, will have her screaming like new again.

Hopefully today, I am off to the hardware store to find a 6mm hex bit that will reach down into the cylinder head to get it off. Wish me luck, and pray I don't strip out the last head stud lol.

-Mike

 

[SparkyMJ]

Alright guys. Head is off, cylinders not yet. One step at a time.

It's pretty crunchy in there as you can see. I'm no expert, but from my observations, the cylinders look to be in slightly differing health, I suspect one running slightly leaner than the other. The cylinder walls themselves look great though. Little to zero scoring/marks at all, just some carbon buildup at the top of the stroke, so I suspect this will be a perfect candidate for a honing, looks so far like no repair is needed. Head gasket didn't blow either, not even close. Looking real good!

As for the cylinder head, it looks real dirty. A good large amount of carbon buildup, valves are a little discolored but relatively normal for their age/mileage. Plugs tips are white, which I think means lean IIRC, but also the way these bikes are mapped is relatively lean for good economy and emissions, so that is to be expected.

Overall, about what I expected to see. I religiously keep up with my oil changes and level, so that appears to be reflected in the tear down. I'm happy to see what I am seeing.
Next steps is to get the head cleaned up, I think I am supposed to do that with the valves still in, but I'll have to do some research to make sure I do it in the right order. Probably a super soft wire wheel on a small rotary tool IIRC what is best for the job, but again, I'll have to research the correct methods. Then, tear the head apart, and clean the hell out of every single piece, inspect the intake rubber fittings and clamps, and check the water channels.

Then I'll take my cylinder block down to my local shop and see what he can do for a hone job on er, and I'll then see my pistons and rings. Rings are getting replaced regardless, but I'll have to do some measuring on the pistons themselves to see if they fit within the spec tolerance, and maybe replace them as well if they're out of spec in any way, which I am expecting. But if they're immaculate, I'll keep them going.

Really excited the project can keep moving forward, slow and steady. Really happy this project looks so far like it'll come out a win in the end. Hope you guys like the read-up! Feel free to ask questions.

-Mike

 

[JFMNINJA300]

Awesome work SparkyMJ 👏🏼👏🏼👏🏼 You obviously have some major skills for this type of engine work!!! I bet the majority of 300s don’t make it past 20/k miles. I had this white 2014 with around 4/k miles that I got cheap from a beginner, that I fixed up did some track days on and sold to another beginner.

Then I picked up another 2014 with around the same mileage around 4/k, again dirt cheap from a beginner. I fixed it up and made it track worthy and have done a few track days on it.
This one pulls harder than the white one with all the same mods except for a full Brock exhaust, I can power wheelie it in 1st gear!

Where do you hit the track at? I am on the north east coast and most of the tracks are very lenient with noise.

 

[SparkyMJ]

Nice bikes man! They look great.

Im in northern Arizona right now for school, so Arizona Motorsports Park in Phoenix. They require stock exhaust (or similar noise levels on aftermarket systems) because there is a golf course right next door unfortunately. It's a bummer, but still a nice track and facility. Back in my home town of Seattle, I plan to go to the Ridge Motorsports Park South of Seattle area, it's an epic track and great facility, and I think they don't care about noise as much. With 300s, really not an issue no matter what you're running. My stock ZX-6R was about as loud as the 300 straight piped lol.

But yeah, with how many miles mine has, it's got some character now, but it still rides great. I figured since it's a little older now, its worth me learning how to do these things on, as opposed to a nicer newer bike, or one that doesn't run as is, you know? Everything in here is functional, so there's no hunting down shattered engine internals or fixing a bent shift fork or something.

If you keep them in good shape, these small sport bikes are tanks, and will run day in and day out. If I can get it to 100 thousand miles, then it's getting a deep cleaning and becoming a living room centerpiece as retirement! Haha. But if I smash it at the track or on the street, it wasn't a huge loss, since mine is probably only worth a thousand bucks as is. Maybe a little more after the engine haul over, but you get the idea. I want more use out of it, not more value. I love this bike, and I intend to keep it forever in one way or another.

I made the thread to hopefully inspire someone to try to fix or maintain their 300 come the day it needs some love, and they can't afford to pay someone to do all this stuff.

Probably tomorrow I will take a crack at the head.

Cheers fellas.
-Mike

 

[SparkyMJ]

Alright, I couldn't sleep, so I took to the cylinder block. Since its getting honed soon, I cleaned it enough to be acceptable for my shop, and then when I get it back, I will resurface and clean it off real good once again. It's got some dirt/bugs/road grime caked on the front side of the cylinder block, presumably baked on from the heat. So I will probably end up using a fine, soft wire brush to try and scrape some of that off, without damaging the engine paint. Shouldn't be too hard, I just want it all looking brand spanking new going back together. I've got a pile of cleaned up parts that are ready to go back together. Pics are of after my cleaning and resurfacing.

Pistons look pretty good as well. The tops are carbon covered, but the skirts and rings look great. A little bit of corrosion on them, but I suspect its mostly just stains I can scrub off. Guess those will have to come off too, and they'll get a super deep cleaning, probably in my ultrasonic parts cleaner, and then I'll hit them with the micrometer.

After all of that, it's finally the time that the project starts going back together. Finally I can start slowly regaining my living space in my house, lol. I think I'll fully rebuild and seal up the engine before doing more external cleaning on the crank case, because I don't wanna get cleaning products inside the engine.

Alrighty, time to hit the hay, it's 4am.

-Mike

 

[MAL]

Block off plate, prevents air being injected into the exhaust which causes popping in after market exhaust. There is only 1 block off plate for the 300 since it is a twin. I have a full Brock exhaust...

Ah, yes, thanks. I forgot. I have the same exhaust, and forgot about the block-off-plate; wasn't there a simpler (read = lazier) way to block it off? Maybe I just plugged that hose up somehow...I forget.

Added: yes, I'm starting to remember now: I recall all I did was shove a conical plastic/rubber piece into the hose to block it off. I knew that plate of yours looked WAY too sophisticated for me!

 

[MAL]

Amazing job, SparkyMJ!!!

 

[JFMNINJA300]

Ah, yes, thanks. I forgot. I have the same exhaust, and forgot about the block-off-plate; wasn't there a simpler (read = lazier) way to block it off? Maybe I just plugged that hose up somehow...I forget.

Added: yes, I'm starting to remember now: I recall all I did was shove a conical plastic/rubber piece into the hose to block it off. I knew that plate of yours looked WAY too sophisticated for me!

I think the kit was less than 20 bucks, wasn’t in a super hurry so no need to try and McGiyver
something to seal the head of the engine and block off the airbox. The kit came with a sexy block off plate, new bolts and a rubber cap for the air box.

Awesome work SparkyMJ, you are the man for sure! 👏🏼👏🏼👏🏼

 

[SparkyMJ]

Thanks fellas!! I'm tackling this whole thing head-on, hoping I'll come out on top haha.

Maybe I'll get the pistons out today. And yeah maybe I ought to order a block off plate and do it right lol. Knowing me, Id plug the hose only to find the plug inside my reed valves in a week lol.

Thanks for the support guys, it'll all be worth it when I take her out to the canyons after it's all said and done!
-Mike

 

[SparkyMJ]

Alrighty. Today was seeing how piston removal and cleaning goes. I took off just one for now, to test my methods.

I got the piston out, wrist pin clip and pin came out pretty easily. No seized rings, but very dirty oil ring, and the 2 compression rings had their gaps aligned (bad) and there was evidence of blowby as I mentioned earlier after pulling the cylinders off.

So I took to cleaning. First, just a round with soap and water, and a toothbrush, to get all the surface grime and oil off, and any easily dislodged deposits. Not much came off. So I ran the piston through my ultrasonic parts bath with diluted Simple Green in 30 minute intervals, each time pulling the piston out to wash it, scrub the carbon deposits, and scrub out gunk in the ring slots. Took 6+ hours of baths and scrubbing/washing to get 99.5% of the carbon off the top, and have all the orifices and slots perfectly clean. A lot of work. I refrained from using any metal picks or similar on the piston as much as possible, but on the last bath I tried to get some of the remaining small deposits out from the valve reliefs very gently.

The piston came out beautiful, I couldn't be more satisfied with my work. I have not measured it's tolerances yet, that is for tomorrow. The piston looks to be in absolutely great shape, keeping up with my oil changes has paid off, and I suspect this will be extremely close to perfect spec. In which case, all it needs is new rings and wrist pin clips, and they'll be going back on. I'll probably pull off the other piston tomorrow as well, and start the cleaning procedure.

Here's a couple pictures of the finished piston, and a before-after. It was a good day, but this is a slow project, fellas.

 

[MAL]

...a couple pictures of the finished piston, and a before-after.

I checked this post on my phone earlier, and looked at the pictures before reading your description; I immediately thought the last two pics were the new piston you bought to replace the old pistons you took out.
That's quite amazing that you got them cleaned up to that condition - your hard work paid off for sure!

 

[JFMNINJA300]

I agree you got that piston super clean looks just about brand new!

 

[SparkyMJ]

Thanks for the kind words! I'll tell you guys, one of the best thing I have ever purchased, ever, is my ultrasonic parts cleaner. It's incredible, straight up magic. For all my hobbies, it's unbeatable in terms of cleaning power, and it doesn't damage things. Anything from engine parts, 3d printed parts, knives, cookware, jewelry, anything you can think of that doesnt melt in hot water can be cleaned. The real magic though is how it cleans inside deep holes and threads and stuff. Do yourself a favor and get one. I put my brake calipers and pistons through it for the last rebuild, and like my piston, they came out literally looking showroom clean.

We'll see what today holds for the project, I have some other pressing matters today, so we'll see what I can get done.

-Mike

 

[Turboblew]

did you weigh the pistons? Why not do the high compression ones?

 

[SparkyMJ]

Because that is a lot of money. Lol.
Been really lazy, but got some progress made. I took the head apart except for the valves. I've decided to leave them in. They don't look too gunky through the ports, and I don't have a tool or makeshift tool to safely do that. So that's staying as is. I did get to start resurfacing the bottom of the head, it had some pretty deep gouges on the surface, perhaps from a past service, but I am not sure. Either way, it's a little rough, and I'l need more than 800 grit wet sand paper to finish that off. But should be able to get it smoothed out.

I've cleaned a lot of random hardware in my parts cleaner as well, mostly the head related hardware. Bolts, nuts, clamps, hose adapters, ect. They came out great. I got the valve cups and shims out as well, sorted on my bench, so at the end of the rebuild, I'll have to shim the valves again.

Cleaned up the mating surface for the cylinder to the crankcase, looks very good. Found a couple small gaskets here and there that were shot or misshapen, so looks like I gotta make a second parts order here soon. Just trying to make sure I get everything else on this second order.

Starting to get a little daunting of a task. I have a good memory, but there are so many pieces now that I have to trust my systems and memory to make sure it all goes back in the right way. The head was a little frustrating not being able to take the valves out, but I think it'll be okay, they look good.

I'm pretty sure I am in as deep as this project will need to go. Nothing else has to come apart. So that is mind-easing. Once my cylinders come back from the shop, and I get my rings and gaskets, the real assembly can begin.

On top of all this though, I still have to do the bike itself. Absolute mountain of a project for one person. I may start doing the cleaning and adjustments to the naked bike while I wait for parts, but probably no more pulling things apart until I can start clearing things up.

My home is a literal bike shop in every room now. To have enough space to lay out parts orderly, every single room has parts. Man I cannot wait for the piles to start shrinking.
Pics for progress, stay tuned.

-Mike

 

[SparkyMJ]

Update time!

So I got my first batch of engine parts in today. I also got my honed cyl block a few days ago back from my shop, it looks spectacular. There's at least 2 batches of parts, because I forgot stuff, and will probably break some more stuff along the way lol. Anyway, today I got:
-Ring sets
-cyl base gasket
-head gasket
-valve cover gasket
-cly block water gasket
-piston wrist pin clips

Got my clean pistons, put the rings in at the angle specified, installed the pistons, and put the clips on. My god, those pins are a pain. I was afraid I needed eye protection a couple times, but luckily, I kept my fingers firmly over the clips, so no flinging clips, and got them in. Just took a lot of wrestling.

I cleaned up the gasket surfaces one last time, and I put the thinnest assembly lube coat on the surfaces and gasket. I was debating doing that or not, the manual mentions no such process. However, intuition from small hobby engine rebuilds suggests at least the thinnest coat to seal imperfections right off the bat. I applied a thin coat with my finger, wiped it off with a clean paper towel, and that is how I put it together.

Getting the cyl block onto the pistons with the new rings was a wrestling match as well. The manual offers no such suggestions for how to go about this, so I did it like I do my hobby grade engines. Had one piston sticking out maybe an inch more than the other, gently twisted and turned and wiggled it in, then push it into the cly block until the other one was ready to be fitted, and wiggled that one in as well.

I knew it was a job well done when I heard the most satisfying 'clack' of the cyl block seating with the crank case. Lol.

Next up is the head gasket. I still need to clean off the oil from me wrestling the block onto the crankcase, and hit the gasket surface with some IPA to get all the oil off, and then I need to finish cleaning the bottom of the head. Once the whole motor is sealed up and clean inside, I'll probably take the whole thing out back and get some simple green and a big brush and clean the engine exterior. She's gonna look good as new, and run awesome!

She's finally coming together, fellas. It's definitely a good feeling. Getting jealous of all the people I drive by riding their bikes.

Updates to come.
-Mike