cool, enjoy

I have not broken one fin since I started doing this, tho I have them front, back and both sides little pieces cut at about 5mm squeezed in like photo tho I have them on the out side not all the way in like the photo only in about 2mm from outer edge between every fin.





It mainly happens from the harmonics from the engine as Grizz mentioned.

Any ideas why i get fuel in the bottom of the chassis near to where the engine connects to the car. I know i am still running a little rich (until I meet up with Dave G tomorrow night as he is going to lend a hand fine tuning my engine)
I have checked for air leaks and the back plate screws as fully secured but just I have cleaned the car and just had it running in the garage and there seems to be a lot of fuel.

I am using now two springs to connect the exhaust to the engine. The 3 small springs on the exhaust seem fine. any ideas please

Thanks
Simon

Let me guesse your at about 1.5 gallons on this motor? I would say its the front engine bearing leaking. they need replacement after the first gallon or so.

I am only about 3/4 of a gallon and it seems to have done since i got the new engine. Is there any special way to put the engine on to the engine and also the 3 springs which also joins the exhaust, and also the height where it sits in the buggy (using the grub screw etc) me thinks may be its not sit right rather than been a bearing.
I replaced the clutch and bearings last night, i guess you mean another front bearing if so where and how easy to do??

Thanks in advance

It is the bearing right behind the fly wheel. The blue arrow in the atached pic points to it. the easy way to tell it this bearin is leaking it to take the motor out of your car and look at the bottom. if it has fuel/dirt built up it is the fron bearing. Also when you are done running do you run your motor dry of fuel??

Thanks for that post mate its spot on

Just checked and the engine underneath is bone dry so seems to be coming from around the exhaust

is that the MGX head flanno ?

i just won a bid for a new gx-7r combo for $240 shipped , it seemed like a good deal i know i want the engine but i know nothing about there pipes, any good???

great pipes!

+1 on that. awesome pipe. A+ if i might say. lol

Was it the EFRA 2072 pipe or the IFMAR 0801 pipe ?
The combo kits come with either pipe depending on what the distributor orders.

Both pipes are very good, but IMO the 2072 is the better performer, plus it has the reinforced stinger and is much stronger pipe all round.
You will enjoy the motor, just check up on the run in and tuning tips at www.go-racing.co.nz on the Tech Tips page.

have you checked the inside lip of your clutch fly wheel ? If you take yoru flywheel off and look at the collett and it has scuff marking on it there is a chance the collett has gouged out a bit of the flywheel material .. It will feel tight when you wrench on it but under load it will slip indipendantly of the crank and seem like lean bog.

Ok So take off the flywheel , look inside where the collett goes and see if you can see a lip .. if its there get a new flywheel and collett and tighten the suckker down hard !

If thats not it then you have to ask why is the engine lean bogging ? It will only lean bog if its starving for fuel. or if its making power but cant get it to the wheels because of something in the drive train.

Lean bog can develop over time if the engine was run in cold
Any sort of Air leak in the tank , pipe , seals , pressure line
HSN needle dirty
Head bolts loose


I think the problem is outside the engine .. check the clutch first ..

hope this helps

Cheers MM

yep

The exact resonant frequency is 1400 HZ .. lower mid range in the GX series and its a little higher on the MG being 4300 HZ . this is a frequency harmonic caused by the vibration energy of the engine, this in turn causes the fins to resonate. the reason why they break is because the radius at the base of the fin is not broad enough to resist the frequency vibration. this is something we are addressing and have been for a while now with a fix just around the corner. the quick fix for now is to put some fuel tubing as seen with Flanno's head. this absorbs the vibration between the fins.

Hope this helps

MM