New Products Flash Sale
Thread Tools
Old Jan 31, 2016, 09:38 PM
Prontow is offline
Find More Posts by Prontow
Registered User
Joined Oct 2008
49 Posts
Discussion
Fuel pick up problem with TTN

OK, so it is not really a Thunder Tiger Ducati, it's the Hobbyking clone. But anyway I was out running it and was picking up a lot of air in the fuel line when the level in the tank got below half full.
Never really looked at the clunk in the tank but it is large enough that the center hole was sucking air with plenty of fuel in the tank. OK I know it is not sucking the fuel but being pushed through by positive pressure from the exhaust before someone corrects my sucking statement .
But I machined out a new clunk with the proper angle so that is stays flush with the bottom of the tank. Milled a slot in there just for added flow.
I was wondering if this is a common problem and is there clunks out there better suited to the small tanks on the motorcycles.
I added pics of the old clunk and my new one.
Prontow is offline Find More Posts by Prontow
Reply With Quote
Sign up now
to remove ads between posts
Old Feb 01, 2016, 02:19 AM
DLAWW is offline
Find More Posts by DLAWW
DLAWW
DLAWW's Avatar
United States, CA, Gardena
Joined Dec 2005
1,034 Posts
Common problem withe TTN bike, from what I remember several things could contribute to the bubbles. Heat from the motor or the valves have an air leak from the housing or the combo of the two.
DLAWW is offline Find More Posts by DLAWW
Reply With Quote
Old Feb 01, 2016, 03:00 AM
z_dad is offline
Find More Posts by z_dad
Kungsangen, Stockholm, Sweden
z_dad's Avatar
Sweden, Upplands-Bro Municipality
Joined Dec 2011
363 Posts
In the 90's we used to put sintered fuel filters for pickup in the tank of our 1:8 buggies. It didn't do much clunk-ing in the tank as we fixed it at the lowest point but it kept the bubbles out and sucked the tank completely dry before letting air into the lines. This method also kept our motors running much longer while turned over. I think these filters are available as a direct replacement for your clunk. Check out your LHS
z_dad is offline Find More Posts by z_dad
Reply With Quote
Old Feb 01, 2016, 07:56 AM
hedgeheli is offline
Find More Posts by hedgeheli
Registered User
hedgeheli's Avatar
Bournemouth - UK
Joined Feb 2009
291 Posts
Hi Prontow - I've had one of these sat on the shelf for a year or so and just this week decided to get it up and running. I have no experience of Bikes but look forward to the journey.

On first look nothing was loctited and the gear mesh on mine was very loose. I also noted the clunk line was so long the clunk was not able to move in the tank so I shortened it enough to allow it to move around the tank. Also the front tank clip - that comes from the steering block - can have its length adjusted by bending it to tilt the tank back hence the last drops of nitro are at the back of the tank.

Few Questions:
1) What Nitro % are you using - I am using 20%
2) Do you have a manual of the Sanya engine? I can only find the main needle and what looks like an RPM screw, there does not appear to be a low needle?

Here is my first run, note I had to bypass the remote glow as something was not connecting enough to heat the remote glow - that's all the wires on the floor - its a rewired Align 2-1 heli regulator

Hobbyking 1/5 scale nitro first start (0 min 24 sec)
hedgeheli is offline Find More Posts by hedgeheli
Reply With Quote
Old Feb 01, 2016, 01:00 PM
Brutus1967 is offline
Find More Posts by Brutus1967
Registered User
The Netherlands
Joined Nov 2009
6,998 Posts
For the second, and all other starts after that: keep the bike vertical (front wheel in the air) if you value your conrod, starter, and starting shaft (engine part).

Don't have the bike myself, but seem to remember from the comments on the HK page, that the idle mixture screw is "hidden" at the part where you can not reach it without dismantling the tank, but I don't know if that is true or not
Brutus1967 is offline Find More Posts by Brutus1967
Reply With Quote
Old Feb 01, 2016, 04:15 PM
Prontow is offline
Find More Posts by Prontow
Registered User
Joined Oct 2008
49 Posts
Yea, these bikes are fairly inexpensive for a reason. But having said that I took the bike out today and got the mixture and idle speed dialed in.
The carb only has the primary mixture adjustment and the idle speed adjusting screw. With the fairing on they are both sort of hard to get to but not impossible. With the fairing off they are easy to get to and adjust.
I was able to run several tanks out with my homemade clunk, and was able to almost completely empty the tank. I also added a small piece of sheet metal to the top of the tank to shield it from the heat of the engine. Stuck it on with double stick tape.
I get lucky and purchased a lot of Thunder Tiger parts from Tower Hobbies when they still had some in stock, they have since discontinued all parts for these bikes so finding good parts are proving difficult.
All in all I am loving this bike, guess that is why I have another coming from Hobby King!��
Prontow is offline Find More Posts by Prontow
Reply With Quote
Old Feb 02, 2016, 07:56 AM
Brutus1967 is offline
Find More Posts by Brutus1967
Registered User
The Netherlands
Joined Nov 2009
6,998 Posts
Unfortunately, I have very few places where I can run one, and they are not close to home.

But I have been tempted very, VERY much....

How are the servos and other stuff installed in this bike (I understood, it is ready to run except for the receiver?)

PS: keep in mind, at least, that was the case on my NF501, that cooling is lots more effective with the fairing on, don't drive too much without fairing....
Brutus1967 is offline Find More Posts by Brutus1967
Reply With Quote
Old Feb 10, 2016, 04:37 AM
hedgeheli is offline
Find More Posts by hedgeheli
Registered User
hedgeheli's Avatar
Bournemouth - UK
Joined Feb 2009
291 Posts
So I was seeing air in the fuel line last week which was cutting the engine. I have raised the front of the fuel tank and lowered the rear - sounds harder than it is to do. Just deeper spacers (replace the nuts) at the back to lower the rear and bend the wire securing the front of the fuel tank to lift the front.

I then tried to fit a Lynx MOAS (mother of all suckers) which is a foam fuel magnet from the heli world - but it wont fit in the tank! Then I thought of a standard 600n clunk which is more tapered - again wont fit in the tank!

Lastly before I closed it up I replaced the stock fuel tube (clunk line) which is thick and rigid, with some thin, flexible, soft clunk line.

I should hopefully get a run this afternoon and see if this helps, if not out with the grinder
hedgeheli is offline Find More Posts by hedgeheli
Reply With Quote


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Question RD TTN Fuel Tank Capacity dragbikebam Motorcycles 0 May 06, 2014 11:16 PM
Question Hsp bazooka dies when fuel dips lower than fuel pick up point????? wishy Nitro and Glow Power Cars 0 Jan 14, 2011 10:42 PM
For Sale PowerMaster Fuel for Sale - Tampa FL, Local Pick up or meet RC Accessory Aircraft - Fuel - Helis (FS/W) 0 Jun 20, 2010 05:46 PM
Discussion Fuel tank set up problems: unable to fill with wind up filler arukum17 Beginner Training Area (Fuel) 3 Dec 28, 2007 03:43 PM
Help! Clunk o Fuel Can Pick Up hobbymx Mexico 19 Aug 30, 2007 11:24 AM