Delta II

**SHELRACING** · 8th April 2009, 09:34

Had to give back the borrowed fxr 150 motor we had fitted to the Delta

Due mainly to finacial constraints, prices and availability of second hand motors we just couldn't afford to fit another FXR motor.

What to do then The Delta was certainly a lot lighter without the FXR motor in it. I tried getting old Grandma wobbler to push me round the Taumarunui track for a few laps. but she struggled on the uphill section of the track.

So I picked up a couple of RX 125 motors on trade me, One definately a parts motor, the other almost a runner. A reasonably good motor came out of the two. picked up a couple of different chambers from trade me as well a pair of NSR chambers, and a nice YZ 125 chamber. All this for half the price of a FXR motor.

Motor's fitted, YZ chamber was used. Initial testing done. A horrendous vibration was discovered (briefly discussed in another thread). The problem beind solved simply by borrowing the bar end weights from my Pre-89 400

A couple of minor issues to resolve before the next meeting, but nothing major. Jetting is still a bit off (more mains ordered). Engine front mount, might change the muffler (but then I might not

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A question for the engineers
This was discussed in another thread as mentioned before. I mounted the engine using only the 2 rear engine mounts. I left out the front engine mount (although it is made and easily fitted now), it is both heavy and extravagant. My vibration issues have been resolved.
Do I really need the front engine mount ? is it acceptable to run on the just the rear mounts.

Steve

**nudemetalz** · 8th April 2009, 13:15

I only run 2 engine mounts on the Longy-Ching motor. Mind you, it's a front and a back, plus the thing vibrates like a ...errr....vibrator?...(whatever they're like....

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**Skunk** · 8th April 2009, 13:41

Have you got a pic of the chain side (of the mount positions)? I'm thinking it'll be better if you have a mount at the front to control the up/down moment of the engine under throttle on/off.

**F5 Dave** · 8th April 2009, 17:15

So make a lighter front engine mount.

You will either need front & back at a min or 2 rear & a front or a head mount.

**SHELRACING** · 8th April 2009, 18:44

Originally Posted by Skunk

Have you got a pic of the chain side (of the mount positions)? I'm thinking it'll be better if you have a mount at the front to control the up/down moment of the engine under throttle on/off.

Yep here ya go

Pic 1. bottom mount.
pic 2. Top mount.
Pic 3. Top mount. The top mount plate sits on top of and is bolted to, the frame cross member.

**SHELRACING** · 8th April 2009, 18:56

Originally Posted by F5 Dave

So make a lighter front engine mount.

Cheers Dave, that would be the smartest move.

My ability to weld anything in aluminium would be non existent.

Considering the weight I have saved in changing the motor. I can afford to use the one I have made until I come to a better soloution.

Hmmm, maybe I could get someone to copy my steel mount in Aluminium.

**Buckets4Me** · 8th April 2009, 19:20

is that an rg50 frame I see in the background

**speedpro** · 8th April 2009, 20:00

I've found that making stuff out of .8mm sheet with a bit of thought you can end up with plenty of strength and not much weight. Roll the sheet round a solid round object of the diameter you want and weld the seam - nice strong tube and light-as.

**SHELRACING** · 9th April 2009, 08:37

Originally Posted by Buckets4Me

is that an rg50 frame I see in the background

Yep and you can't have it

**SHELRACING** · 9th April 2009, 08:42

Originally Posted by speedpro

I've found that making stuff out of .8mm sheet with a bit of thought you can end up with plenty of strength and not much weight. Roll the sheet round a solid round object of the diameter you want and weld the seam - nice strong tube and light-as.

There's an idea

Cheers