Mrs. 2LZ TT250. Into the Fire....
 

....and out like the Phoenix.

Hi gang, Just wanted to give you all a heads up on the latest project. After our morning ride today, the TT250 will be going on the rack for the tear down. I have about half the parts here now and the rest should be arriving sometime next week (hopefully).

For those who wish to follow along, the project will consist of the following, but I'm sure will change as it goes along.

Motor, starting from intake: New K&N style breather, Mikuni carb with a mix of jetting, post-break-in valve adjustment, swap to iridium plug, new exhaust (wrapped), switch to synthetic oil. Re-torque every motor mount.

The rest: Go through the forks, new fluid. They've been working sub-par to date, are still slightly twisted in the trees (binding) and they seem over-filled on fluid (just guessing). Drop off rear end including swing arm and shock. Grease everything as it should be, including link and readjust the shock. I currently went overboard on softening it for Mrs. 2LZ. Replace the stock horrible chain with a new one. The stocker, regardless of lube, insists on kinking in spots. Unacceptable. Replace the stock 50 tooth rear sprocket with a 47 from JT Sprockets. I'll be gambling on a JTR269.47. Also, on top of the already added cockpit bling, I'll be mounting some 30mm Tusk risers, per Mrs. 2LZ request. If I forgot anything, I'll add it later. In addition, if the new gauge cluster from "mjstef" comes through, that will be part of the project while I have it down. Also, I have two new Kenda Tuff Tubes in stock....but I may not change out the original China Condoms until they blow. We'll see. So far, they're holding and I may just wait till I swap to the Shinko 705's...but surprisingly, we're really liking these stock tires so far for our riding habits.

Schmise: Safely remove and store everything smog related. Make a plate and block off the hole in the head for the pump. Finally, weigh everything between old and new to see overall fat savings. I'm hoping to gain a 3-4 HP (per butt dyno) and lose up to 10 or so pounds. Just guessing at this point.

Anyway, stay tuned if you wish.... Many pics to follow.

Are you sure you want Shinko 705's? I think they are the absolute worst tires on the planet.

Good luck on your weight loss;)

This is going to be great.

Just wish had actual stock basis dyno :shrug: course which would you rather do spend money on dyno test or on actual Mc parts, I think we know the answer. :hi:

[QUOTE=BlackBike;225161]

This is going to be great.

DITTO ! :tup:

I think 2LZ was a Dokken fan back in the 1980s.

Nah..... I was more Hendrix, Zeppelin, Cream, Airplane, Alice Cooper.....

Strange. They rate well and supposedly better than my Kenda's that I like on Q. We'll see....... The stockers sure seem to be surprisingly good for a stock tire regarding paved twisties and dry gravel roads.....

Headway
 

I got up early this morning, posted the thread and then headed out to the garage to get everything ready. Cleared a shelf and a bunch of bins. ready to play!

Got back from our morning putt around 11:30. Got the TT on the rack around noon and went at it. Being a NASCAR fan, it was a tough job thanks to Loudon NH. Mrs. 2LZ would yell from the house, "Yellow! 18 out front!"...and I'd have to run in and see the restart. Needless to say, it was "Wrenchus Interuptus" quite a few times today....but I persevered. The bike had 13+ hours on the clock since I installed the tach unit so it's ready to go!

There were quite a few things I discovered today. First, I'll need to get a hunk of black plastic and fab an inner rear fender if I want one. The back of the air box plays that roll and it's now in the pile. No big deal.

Secondly, as expected there is very little grease on the swing arm pivot, axles or shock links. Also, I think with the scads of these CSC got in and needed to ship, it was pretty obvious that the valve cover had not been off. I think they give them the "does it rattle?" test and if so, send. Can't blame them really. The bike ran really well.

I took off all the smog, blocked the vac port on the intake manifold the old fashioned way (which I may replace) and fabbed the plate for the smog pump hole at the head so it's ready to go. Carb, exhaust, etc....all in a pile now. Need parts.

I was VERY impressed with the machining. I thought the rocker assembly was nicely done on my Lifan motor, this was impressive. Nicely done by Zong.

I got those ugly, scratched up bars shot today in the closest thing I could find to the dark, dark gray that's on the plastic's The pic doesn't show it but it's a very close match. Good enough.

Anyway, the bike's down, on TDC and ready for the valve set tomorrow after work when it's ice cold. I think that's about it for now.........

Continued
 

More pics...

I here ya,(worn out cassettes of dokken,scorpions etc) back up a couple of generations for 2lz.

What is the perceived benefit to installing a Mikuni carb as opposed to simply re-jetting the stock carb? Are the venturis different sizes?

So there were still some gap on the "air valves" as the owner's manual calls them?

Thanks for taking the time and posting all this stuff :tup:

Also, could you show a pic of how to grease the swing arm when you get around to it.(other than just greasing the bolt, is there actual bearings?)

Thanks

i am sure you thought of this already, but you may want to put the new parts on the scale before you install, for a true number of reduction of lbs

Yep... I'm just waiting for the carb and breather to arrive for this. I have a bucket on a scale and I'll tare the bucket weight prior to weighing for comparison. See if it's worth it for anyone else to try.

The swingarm is just bushed. There was some grease on them but I'll be coating the entire pivot bolt with a glaze of grease just for the corrosion aspect, along with regreasing the bushings. I've had swingarm bolts rust in place. Not cool.

I'll be posting what gaps I find in the "air valves" after tonight. They did tick so that's good.

I chose the Mikuni (thanks to Weldangrind) for a few reasons. One, when I bought my first one, it's a nicely done carb. Machining was superior to the PZ I took off. Mostly though because of the availability of jetting. I'll be measuring the carbs to compare and post my findings.

Rust...then starts wearing grooves on the bolts..

Thank you very much for this info. I had visions that there were bearings going dry in there (like crunchy...mann). That sounds easy.

I still am waiting for rear wheel assy so I will be sure to address that while it's disassembled.

I hope you vets don't get tired of re-hashing this info year after year to us noobs! :hi:

More pics
 

Just a couple more pics that finally showed up from the stars overnight.

This was the basic condition of the bar paint overall, not just under the switch gear. Not sure about anyone else's. Fixed now.

Also, I found out why the stock plastic license plate frame was rattling like hell before it broke in half, leaving it on the road. Apparently, the factory plate holder doesn't accommodate US license plates and they drilled them at CSC to mount the dealer plates. Not the greatest job. Had to bust out the Dremel to fix when my plate arrived in the mail. No way it was going to mount.

So cool! I haven't seen a teardown like this in some time.


A sideways H-shaped license plate holder might last longer and protect the plate better; an unsupported plate can crack. I can't remember - do you have a welder?


The vacuum port on your intake tube would be very useful for tuning. A vacuum gauge can tell you a lot about jetting, valves, etc.

Thanks Weld! So far, it's been a ton of fun. These CG's are like wrenching on a one cylinder Panhead and the Hondoid itself, not much has changed but wow...things do fit and bolt together much better than on the CB's a decade ago! No need to keep a drill handy anymore! LOL!

yeah butt, on loose grav,wet grass, or 1/4 " mud or better, that front is washout city!
immediately swapped mine for a tr8, diff between 'chit and chocolate:)
first thing you notice, stock tire is wayyyyy lighter, thinner walled, definitely 80/20 90/10 road biased tire. if that's what you ride, you'll b happy. if you want to follow your buddies/ kids "OUT THERE", swap it out and save yourself some headaches, (and various other contusion caused pains). Also, as my mechanic said when he saw the stock tube, "looks like a mountain bike's!"

The TR8 in front transformed my bike. now feels VERY solid and planted on road. It may make the bike a hair slower, but the feel of security and added confidence is worth it for me. no increased vibration, or noise to me.
Rear seems ok for now while I'm breaking in, but the difference in profile, aspect and traction between the stock rear and the Hawk's knobby is DRAMATIC.

2LZ, now that your naked, so to speak, you can grease connectors and tape them up for waterproofing. (Not speaking to you , you taught the course).

I greased my swing arm bolt and rechecked the valves also today (2nd time easier now that I didn't have to us a Sawzall and a weld and grind routine like the first time). Set them both at .008mm

Also noticed a broken angle iron mount for the mid pipe to the muffler. Will have to weld err up. Found a few wires trying to comment suicide on the hot engine too. Can't take anything for granted with these scoots.

Thanks again

2LZ... would you consider a light coat of clear satin or gloss now that the frame is so exposed for additional rust proofing. Oops, I forgot you are in california, no rust!

wondering if I could install a zerk grease fitting on the swing arm to make greasing easy

I'm sure it can be done but the grease sits mainly under the cups on the bushings. The main pivot axle just passes thru the swingarm. I was going to put a light coating of grease on it just to ensure its removal next time around, not for any actual pivoting purposes. The cups and bushings take car of that.

Like I said in a prior post, I had an old Yamaha swingarm pivot bolt rust in place, thanks to the creek I grew up on. It took a big hammer and an Ohio Speed Wrench to bash it out. It didn't make it.....but at least I could then replace it.

Smog
 

Last night wasn't too productive but I got some done. Work nights with our schedule make for short wrenching, especially Mondays.

After gutting the purge canister, air pump and all the other schmise, it was time to plug the head hole. I took some of that angle iron I made the Rhino hitch out of and cut a small piece for a plate. Luck would have it that it was just slightly thicker than the pre-existing piece so it all worked out. Some bench grinder and wire wheel work, a little high temp paint and viola! Plate.

When I removed the original hose inlet, just a skin of the gasket came away with it so I put a light coating of high temp copper (header) silicone on the new plate and sealed her shut. No more smog!...and no worries about possibly baking the packing in my new muffler.

Check out this on the Watt-Man website, people are doing similar things to their KLR 650s... I'm sure grease fittings can get put on our China Bikes also ;)

http://www.watt-man.com/uploads/ZerkInstallation.pdf

Forks Fluid
 

I have to give it up to Zongshen for quality control on this one. Only on Q, have I ever had a CB that had the exact same amount of fluid in each fork. After draining each fork down to the "one drop per second" count, I was amazed at the results. 320 cc's from each fork. Of course, there's always about 10cc or so left behind so I just added 320cc's of my favorite Bel Ray 10W to each fork and called it done. FYI- the stock fluid seemed fair but had a funny smell. I'm glad it's changed.

Then, this morning I woke up thinking it would be a great disservice to our humble community here if I didn't attempt to repair the "leaky adjuster screw" some of us have. My right one has been weeping. I'll be looking at that tonight to see what I can see.

Valves
 

As feared, like all other CG motors I've had, the valves from the factory were tight. The intake came in at about .02mm at the most, and the exhaust came in at about .04mm, max. It was a TIGHT .04.

As usual, I did .05mm on the intake and .08mm on the exhaust. No more worries.

That looks like a great idea! I was thinking of a zerk in the middle of the swingarm. My mistake.....

This thread brings me so much joy!

I've got one dismantled at home

CSC sent me a replacement cap to install so after I did that I dismantled the original one to find the o-ring with a section that was pinched off during the installation. I plan to rebuild it with a new better o-ring to keep as a spare.

Awesome news! A screwed up o-ring was what I was hoping to find. I'm glad though that CSC backed you up with a new part. Great service.
I have a ton of O-rings so I'm hoping I have the right one in stock....

I'm 90% sure I have the right size in a basic butyl rubber o-ring, but I'd like to replace it with something a little more robust and less prone to pinching.

That sounds like all the qualities of a really good beer! ;-)

Whaddaya know, I've thought the same thing about one or two of my kids! ;) :hehe:

Forks
 

Good morning fellow China Riders.

As kohburn and I discussed yesterday, I decided to open up the right fork and go in after that o-ring. All was going well and I was taking pics as I was moving along....until I got the cap off, the fat rubber washer removed and placed it in the vise. BTW, the cap is held in place by the usual double-nut setup.

On a side note, it is kinda cool how that little screw/rod works, once I got it in my sights (see pic on workbench with needed supplies on hand). I can tell you that the little screw head is "in place" in the cap and the rod threads into it, via a slot and flat blade type of joint. The tricky part is when you're screwing that rod back into the cap....to line up the blade with the slot and finish threading it in. If the screw isn't turning as you turn the rod, they aren't mated together. Keep that in mind.

As you can see, the inner piece of that cap has been thread locked with something akin to red locktite. I had a long wrench on it trying to coerce it back and forth but to no avail. I didn't want to destroy it or spin off the aluminum head of the thing. I was aware that something like this may occur from a post I had read on advrider but I was hoping for a work-around.

In the meantime, I've emailed Ryan with a pic and am hoping for a warranty replacement for it....before I take a torch to this one and try to bust it lose. We'll see. I just didn't want to go after this with a torch yet until I had a backup.

Carbs
 

Not like dual carbs...(yet)...but like the Mikuni vs the Keihin clone PZ.

I got the Mikuni last night and already had the jets on hand from Jets-R-Us (they always ship to me blisteringly fast).

I unboxed the Mikuni and it was the usual, nicely done carb that I've received in the past. I installed the jetting I'm starting with (25/110) and set the screw at an even two turns out just for reference....then mounted it on the TT.

I don't have comparison pics because..well..I blew it....but I have to give another "hats off" to Zongshen for the PZ carb they are using on the TT250. Compared to the POS sealed up PZ that came on my Rhino (it looked like a sandcasting from a 5 year old, gone bad), this PZ carb seems a really nice piece. So....that being said, unless you want all matching carbs on your Hondoids for jet swapping...and especially if you do the cheap PZ rebuild kit that has the real mixture screw like rojo linked for us....I really don't see any reason to spend the 30.00 to swap it out, if you have the right jetting for your mods/elevation. Really.

I'm going to keep the PZ as a backup and stuff one of those rebuild kits with the screw in it.

[Q UOTE=kohburn;225436]I'm 90% sure I have the right size in a basic butyl rubber o-ring, but I'd like to replace it with something a little more robust and less prone to pinching.[/QUOTE]

sounds like a friend's critique of the population in the Florida Keys, specifically Key West!
(for you straight east coast and midwest types, think Province Town Mass or San Francisco :)