Today I made a start

[Fonfe]

Finally got the bike to run!!
Well for a whole 3 mins :oops:
Came to the conclusion that I wasn't getting any fuel into the combustion chamber so pulled the carb apart......look what I found.... yes that is a piece of HAIR! 8O


Cleaned it all out, and the jets, slapped the carb back on and she started at the first touch of the button! Pushed the choke back in and she dies immediately :(
Tried restarting with the choke out again but no joy.
Pulled back off again and it seems the previous owner put so much sealant round the rubber connecting hose that the carb only just slides in and when the hose clamp is tightened it pops it back out a touch.
Going to remove the joining hose from the head tomorrow after work (didnt bring any femal Torx sockets home with me today) clean all the old sealant off and refit it properly. My thoughts being that if done correctly then it should require any sealant.....

One thing though:
The carb has a inwards ridge for the hose to seat on. But the hose also has a inwards ridge? Surely one should have a inwards one and one an outwards one aka one becomes female and one male to seat the join and seal it correctly? Is everyone's like this or is mine a cock up from the factory? :?

[zingshoen]

do you mean the plastic intake boot? its not a manifold :-)

it s a funny rubber fit over the carbie, don t overtighten the clamp or the plastic will break. it is the shoddiest intake principle available. i m sure you ll find a way to fix it.

best option may be to make one up from scratch, though, using manifold rubber compound. i ve read about it on page about guys racing a zongshen engine in an xr frame , but haven t done it myself.

[SpudRider]

The hose from the carburetor to the cylinder head and the carburetor itself should have mating "nipples." This hose should connect with socket cap bolts. It sounds as if the previous owner might have installed a different hose. :roll: Neither of the carburetor hoses should require any sealant whatsoever.

The hose from the air box to the carburetor is actually manufactured from a very tough, slightly flexible plastic. :roll: I suggest you save yourself a lot of grief, and purchase the Yamaha air cleaner joint, part #6 in the following diagram.



The carburetor will have a much better seal, and will be far easier to remove and install if you purchase the Yamaha hose. Substituting this hose is one of the best modifications I have made to my Zong.

If the hose to the cylinder head is not correct, I also suggest you get Yamaha part #1.

Spud

[Fonfe]

Yer that's the one! From the cylinder head to the carb, that's why I called it a manifold lol essentially it's still a manifold, just a rather crap one!
Think ill fab one up from ally at some point with a silicone joiner hose, but for now ill take it off take the sealant off and see if I can get a decent seal.
Thanks for the parts info spud, will look into getting the yamaha hose

[SpudRider]

Make sure the O-ring in that short hose is in good condition. A bad O-ring will allow dirt to enter the engine, damaging the intake valve and its valve seat.

Spud

[zingshoen]

SpudRider, just to make sure coz i don t know: is that the Yamaha diagram for a TW 200?

Fonfe, I found it crappy too and it breaks easily from new :? make it firm but not tight, then let it sit, perhaps "firm" a bit more.

the root of the problem on mine was that the carbie hangs between that intake boot and the plastic hose from the airbox. however, those three elements didn t measure up correctly, something was too short...and i bought mine new!

[Fonfe]

Dude that's exactly my problem!!!
Removed the whole lot this evening, fitted the carb to the inlet hose, perfect fit after cleaning it out. Fitted back p to cylinder head, still great. Fit the air box and the air box hose....it all pulled the carb out a touch again :( bike runs but only with the choke on full so in other words its letting in air from the crappy seal.
Think I may give slotting the air box mounts a go to push it further forward and if that fails ill be on the hunt for a ever so slightly longer hose, only needs to be about 3mm :(

[zingshoen]

slotting the mounts could do the trick. i got rid of the whole setup, bought a 28mm mikuni and added a unifilter. i extended the bracket which holds the oil drip box (above the header, opp. the petcock) to support the carbie.

if you make the inlet/carbie connection tight, try to support the carbie and then use a bit of pipe and two clamps to bridge the gap on the airbox side of things, or a piece of foam over the plastic hose with a radiator hose clamp? then you can ride until you get that yamaha airbox hose. i find yamaha parts really exxy. perhaps better to order in the U.S.

but i gather from spud's advice that it may give you those 3 mill, which is all you need.

[SpudRider]

Originally Posted by Fonfe

Dude that's exactly my problem!!!
Removed the whole lot this evening, fitted the carb to the inlet hose, perfect fit after cleaning it out. Fitted back p to cylinder head, still great. Fit the air box and the air box hose....it all pulled the carb out a touch again :( bike runs but only with the choke on full so in other words its letting in air from the crappy seal.
Think I may give slotting the air box mounts a go to push it further forward and if that fails ill be on the hunt for a ever so slightly longer hose, only needs to be about 3mm :(

Don't tamper with the air box. :? Buy the Yamaha, TW200 carburetor hose shown as part #6 in the diagram above. This hose is inexpensive, and manufactured to a very high quality. It is a perfect fit for your Zongshen 200GY-2. It will provide a perfect seal, and it will make removal and installation of the carburetor an easy task. I have installed the Yamaha, TW200 carburetor hose on my Zong, and it's one of the best modifications I have done to the bike.

The crappy, plastic, Zongshen carburetor hose is easily removed from the airbox. The Yamaha carburetor hose is easily installed, and fits perfectly. I strongly encourage every Zong owner to install the Yamaha carburetor hose as quickly as possible. It will make your life much easier.

Spud

[SpudRider]

Originally Posted by zingshoen

SpudRider, just to make sure coz i don t know: is that the Yamaha diagram for a TW 200?...

Yes, I bought the carburetor hose for the 2006 Yamaha TW200. However, I'm sure the hose is the same for the 2013 model as well.

Spud

[zingshoen]

thanks spud, good to know

[Fonfe]

Well I haven't had a chance to touch the bike since the last post as I've been dealing with my rather wet range rover......(this I why I want to have the bike so I can abandon the rangie and ride home/for help instead of waiting for a lift off someone else -got home at 4am that night!)

And before anyone thinks I was being a pussy in the water my bull bar is chest height aka it was deeeeeep water :oops:

But on the plus side whilst I was at work I had a thought:
If I order a tw hose it'll take forever and a day to get here as tw's weren't sold in Australia and the problem with the current hose is that its a few mm too short.
So I got some scrap ally plate, and I've made a spacer to bolt in between the cylinder head and the carby. If it works it'll be great. Can't see why it won't, it's 3mm thick ally plate that should handle the heat warping without issues and I shall use the same sealant I use for crankshaft ladder gaskets at work and 3mm longer bolts that are normal hex instead of Torx -really who carries female Torx spanner round with them in their bike tool kit?!
Only issue it may have is it will upset the idle a tad I'd imagine? Only ever so slightly but may not be able to notice any real difference. But should give bit more bhp but we are talking 0.01 of a bhp haha
A thinking this purely because with an injection system on a conventional car engine the closer one can place the injector towards the intake valve the smoother the idle is that can be achieved but the further away from the inlet valve one places it gains more torque and power at the loss of a smoother idle. (All to a specific limit obviously but we aren't talking about putting an injector 1 foot away from the inlet valve)

I could be totally off the mark though as I've never dealt with carb systems in the past only with injection set ups and carbs are a new thing to me.

Spud - if it works, may be worth a sticky as a cheap alternative to getting the tw hoses?

[SpudRider]

That's nice fabrication work, Fonfe. I hope the spacer works well for you. Please note, another Zong owner has stated you can slide the plastic hose forward about 3mm from the air box. Zong owners in North America are fortunate, since the TW200, air box boot only costs $13.

Spud

[Fonfe]

Well it fitted up perfectly
But still won't run without the choke on, unless throttle is held half open.
Can twirl the pilot mixture screw any direction you fancy and it changes nothing....thing the jet is buggered?

[Weldangrind]

Nice fab work! If it still won't idle without the choke, maybe a fatter slow jet is a good idea.