Re: Honda Dio, Activa and Aviator

Hello Guys, Yesterday when at a red light, an uncle stopped near me and started noticing my Aviator. At first i didn't knew what was he looking for. But later he said, that isn't Aviator is a bit higher in stance than the Activa, he even said that my Aviator is even low than the Activa. Which, when i noticed i realised the same thing. And even realised that the front suspension is a bit low, when i pull the handle upwards with my both hands then i also realised that it is not in its highest position when standing on its own. So what can be the problem/solution can anyone please explain.

Re: Honda Dio, Activa and Aviator

Coincidently/Fortunately/Interestingly during my fiddle with AFR screw and Idle-Screw, I've returned AFR to original position and tightened Idle-Screw about 1/8 (or less).

Roll-on speed/acceleration was better this time(after adjustment) & I touched 70 km/h on speedo. Will ride on a better road this evening to find out if it's giving up at higher speeds.

And I forgot to ask one thing earlier. I noticed two vacuum pipes originating from intake manifold.
- one for SAI/PAIR for emission standards
- another is hooked to bottom of fuel-tank along with fuel-hose.

How does second one work?
Does that mean this tube controls the on/off fuel flow? i.e only opens when engine is ON.
And I can safely open the carburettor as fuel-flow will be off(no fuel-petcock here)

Re: Honda Dio, Activa and Aviator

Its the fuel cut off thingi. Ensures flow only when there is suction from the motor. Le Kiney also came with that.

Re: Honda Dio, Activa and Aviator

Btw, scooter(Dio[2011-102cc]) registers 85 km/h on the speedometer. Until 75 km/h noticed good pick up from there on it takes time to reach 85 km/h.

You mean Kinetic Honda?
This implies, all scooters have similar contraption in place to regulate fuel flow to carburettor, no?

Re: Honda Dio, Activa and Aviator

it does have a petcock (just that it doesn't have the manual on/off knob.. its a vacuum operated petcock) the two pipes you see coming out from the petrol tank are actually coming out from the petcock (the exact part name i can't remember at the moment)and IIRC it costs 350rs. one is fuel pipe and second one is a vacuum pipe that helps regulate the fuel flow (akin to 'on/off' knob on a manual petcock) . i normally unplug the tubes at the engine/carb end and route them upwards. you can blow thru the vacuum hose, to get fuel from the fuel line (like if you need to take out petrol in to a bottle for some reason like cleaning parts etc..)

Edit: hope this pic helps:
6 is fuel tube
7 is vacuum tube
1 is petcock assy which has a fuel strainer (2)

Re: Honda Dio, Activa and Aviator

That is how a G-power plug should look like - clean at the fine tip . This plug reached self cleaning temperature at the tip , which is ideal and burns off any carbon from the tip automatically . The carbon around the circular base part is from running in low rpm in city traffic , not any mixture issue - i.e is normal and doesn't affect performance any ( my plugs are always like that from constant city running ) . Do not fiddle with adjustment screws . The stall at idle indicates a clogged idle-jet inside the carburetor - only solution is to open it and clean . Idle jet holes are quite small and clogs from time to time . The engine shall stall at idle ( traffic signals and speed-brakers ) even after warmed up . On a well warmed up engine , leave the throttle and see if it can run on at idle by itself like that . If it stops , clean that jet . Clogged idle-jet is not obvious at higher speeds because then main-jet is supplying all of the fuel needed - so high speed run is not affected . Also another indication of clogged idle jet is lowered fuel efficiency , since now the larger holed main-jet is supplying fuel all the time , i.e even at idle , when little fuel is needed and excess is wasted .

Re: Honda Dio, Activa and Aviator

Then this Christmas that carburettor is getting a cleaning. Will posts some photos of it.

btw, ODO reading is 14,500 km.

Re: Honda Dio, Activa and Aviator

Surely do post loads of pics , we all love to ogle at other's bike parts . When a bit of dirt shall enter with the fuel and come to get stuck in one of the needle thin orifices inside there and cause mischief is a matter of divine destiny and not kms run , so ignore the odo about this . See if you can get hold of a can of carb-cleaner like cyclo etc - makes the job much easier .

Re: Honda Dio, Activa and Aviator

Yup, Kinetic. Yes, every scooter I've come upon has this.

Re: Honda Dio, Activa and Aviator

Today, I gave my activa (102cc-2005 model) for half engine rebuild to a trusted mechanic. I hope he will do better job than ASC as per my past experience. I had said before the inlet valve is close to end limit and engine was consuming oil at high rpm, which required topup of engine oil very frequently every 500kms. After opening the engine, he said the following work needs to be carried out:

1. Valve kit- (The inlet valve had gone flat.)
He will send head to lathe guy for New valves seating, changing 1 valve guide and repairing internal threads of spark plug hole

2. Rebore with New Piston.

According to him crank is still good.
So what do you think, how much that lathe can charge for above work ??

The major parts will cost as below:
Honda Valve kit: Rs. 400
Usha Piston kit: around Rs.600
Rest will be engine oil, head cover rubber gasket, half packing kit, Engine mount bushes...

I couldn't spare time to take any pics. Most probably, lathe job is completed today and tomorrow morning I will try to take pics of worn out parts and during assembly.

Re: Honda Dio, Activa and Aviator

Lathe charges for the re bore and valve replacement should be under 400rs.
what size are you reboring for .25 0.5 .. ?

Re: Honda Dio, Activa and Aviator

This is the first rebore. He is making it for 0.5 piston.

Re: Honda Dio, Activa and Aviator

nobody does a 0.25 i guess ..no issues anyway. it's not a two stroker like the rx whose bore kit is rare to come by.
just sit around and watch the mech assemble everything. and make sure the clearance is not too much between bore and piston.. unfortunately i do not have the tolerance limits handy.

Re: Honda Dio, Activa and Aviator

Rebore job is completed. It costed me around 2500. The mechanic charged me labour as 700 for engine work and 500 for lathe work. Lathe work includes Reboring, 1 valve guide, both valve seats, internal threading of spark plug hole. I have collected the parts back. I hope he must have done the job well. Lets see how much kms the new bore can clock.
I will ask my sister to follow the Run In period for 500 kms and will change the engine oil after 200-300 kms.
Also I took some pics. I will try to upload them tonight. [MENTION=16602]s1d[/MENTION] thanks for your inputs.

Re: Honda Dio, Activa and Aviator

Update: Warning: This is a long post with 15 images
Please feel free to comment on below. This will boost our knowledge and help to correct our mistakes. I think this is going to be useful for other members looking for engine work.
I will update the costing part soon.
Old parts:

Inlet and Outlet valves


Observe Inlet Valve is totally worn out


Old spark Plug. It was NGK, replaced sometime back 8000-10000kms.


Piston Standard size




USHA mark inside


Old Engine mount bushes:




Lathe work:

Rebore.
Check those clearance. What do you say?


Head job done


Spark plug threads are rectified now.
Valves are properly seated.


New Parts:

Usha 0.5 piston




Usha logo, I hope this is not a fake one.


New spark plug. Bosch this time


Jaso MB Honda Engine Oil.