300cc Kit

[2LZ]

Originally Posted by rjmorel

2LZ, a question for you that I've always wondered about. I'm basically a 2 stroke guy from the 70's and haven't fiddled much w 4 strokes.
Question is when you take top end apart how do you know when putting it back together to get the cam chain timed correctly so valves are not opening at wrong time? Are there marks on chain and cam? What about where it goes on crankshaft end? thanks rj

I'm an old two stroke guy too!...and man were they faster! My 250 Husky would absolutely smoke the RX3 or our TT. No comparison....and far easier to work on.

Back to the NC250. I tore it apart on TDC. I used the zip tie trick on the chain so it wouldn't get lost in the case when I pulled the cam.

Upon reassembly, I made sure the crank was still on "T" thru the lower peep hole, then set the cam so the two marks that you can see thru the top peep holes on the cam gear measured the same height off the rocker deck. The lobes will be poking down.

Then I crossed my fingers, installed the cam and remeasured to make sure they didn't move while I was fighting with the chain. You have to rotate the motor a little to pop the chain on. Tight fit. When I rotated it back, it all lined up.

[2LZ]

Originally Posted by sqwert

Looks like hood and base gaskets come with the kit. NZ tossed in what looks like all the pieces to do a complete top end overhaul, and then some.

The only part mine didn't come with was a new chain tensioner gasket. The one that came off the original barrel was perfect so I just reused it.

[ChondaChondaChonda]

One tip I will throw out there is to loctite the sprocket bolts if you take them off.

[Duckati]

I'd figured lots of folks here also cross-reference the ~300 page advrider RX3 thread and vice versa, but FYI to all, an active member on both sites asplode-go-boom-grenaded his NC250 a couple days ago after installing this kit. He seems like a decent wrench, but assembling an engine, however simple the engine, isn't without possibilities for error, nor do we know what kind of QC these kits go through, despite the incredible jewelry-like packaging and fit/finish. I'm now a little tentative to venture down this path, but with more and more others here having success, and as little as I've invested in my bike, I'm still likely to move forward with it. More feedback until then is very much appreciated!!

[NzBrakelathes]

Originally Posted by Duckati

I'd figured lots of folks here also cross-reference the ~300 page advrider RX3 thread and vice versa, but FYI to all, an active member on both sites asplode-go-boom-grenaded his NC250 a couple days ago after installing this kit. He seems like a decent wrench, but assembling an engine, however simple the engine, isn't without possibilities for error, nor do we know what kind of QC these kits go through, despite the incredible jewelry-like packaging and fit/finish. I'm now a little tentative to venture down this path, but with more and more others here having success, and as little as I've invested in my bike, I'm still likely to move forward with it. More feedback until then is very much appreciated!!

The thread there very much suggests something without good clear evidence, I wonder and kinda think it was assembly error and I forwarded all the photos to the factory to see if they can shed any light on the matter.
1000's are sold in China and all go on the Carb version dirt bikes - this idea is not very new etc and I think some NEW dirt bikes get these kits before being sold as ell (I might be wrong tho)


I am currently fitting a kit to my TEST/R&D RX3 etc and I want to look at further developing EFI option or tune option as well as many and any other possible upgrades that people/customers might like and find useful etc.

I have 1 spare kit, I need to order the 4 pot caliper set up with master cylinder etc and in time I will look at hydraulic clutch with the matching left side master cylinder.

Handle bar riser - any call for these? a couple styles are availble.
Bush guards with tidy adapters and hardware might be useful but I wonder if economical enough with DHL etc.

Oil filters are a little cheaper here but 6-10 at a time with shipping isn't well priced (unless you add to another order) I also have the mesh type filter.
Air oil fuel filters maybe a good top up with orders but I kinda doubt sending just 1 will be economical etc.
Thought opinions welcome etc.

[2LZ]

Took it out for a short run again last night......down to my little town to have a beer with the Bench Buzzards and solve all the worlds problems.

It's no secret I'm a big "break it in according to factory specs" kind of guy and I can tell an improvement with miles. Chonda is right on the money when he says that it gives a little more across the board but it really helps down low. I now have more usable (not monstrous) torque around 3500+.
My particular RX3 had nothing under 5k, until I did the pipe. It helped a little. This kit's helped that even a little more. It's now comfortable running around in mid-range. I don't feel like I have to ring its neck to get it rolling.

I do have a funny occasional flat spot rolling from mid-range to top end but we'll see if that goers away with miles.

[Juanro]

2LZ, did you noticed new or increased vibrations?

[2LZ]

Originally Posted by Juanro

2LZ, did you noticed new or increased vibrations?

Zip, zero, nada.....at least yet. I don't ride hard at all anymore though. The old guy you see mildly cruising the back roads with a funny looking helmet, that's me.

Who blew theirs up?

[Juanro]

Originally Posted by 2LZ

Who blew theirs up?

Peter? Young, I think username was pyoung or something like that, weren't he a member here?


http://advrider.com/index.php?thread...#post-35120713

[2LZ]

Originally Posted by Juanro

Paul Young, I think username was pyoung or something like that, weren't he a member here?


http://advrider.com/index.php?thread...#post-35120713

Wow! That really sucks! pyoungbl. I wonder what happened!? How many miles did he have on it before it grenaded?
Wake up 2LZ....just now saw the link.

[2LZ]

This is bizarre and I'm hoping it was just faulty casting or something. Chonda has been beating the crap out of his 300cc kit with no issues. I'll take it out again this evening and specifically feel for more vibration.

That motor looks almost like Paul lit off the nitrous.

[Juanro]

Yes, very strange. He did less tan 50 miles before KaBang! and he felt the vibration at once.

[2LZ]

Originally Posted by Juanro

Yes, very strange. He did less tan 50 miles before KaBang! and he felt the vibration at once.

One of my neighbors put in one of the wrist pin clips. If mine grenades, I'll just blame it on him. A guy always needs a backup plan...

[Juanro]

Originally Posted by 2LZ

I'll just blame it on him. A guy always needs a backup plan...

Or a escape goat

[Jay In Milpitas]

Originally Posted by 2LZ

One of my neighbors put in one of the wrist pin clips. If mine grenades, I'll just blame it on him. A guy always needs a backup plan...

Please notice that Peter's picture of the top of the con rod shows the pin centered in the rod meaning that it hadn't shifted to one side. The shot inside the barrel also doesn't show a linear wear mark that would correspond with pin shift.