3 generations of Muncies impulse bought the same GN125.....

[ultra]

On 10/09/2023 at 17:20, zach_munce said:

@ultra I'd be keen to swap depending where you are

Sorry just had them taken off and they are damaged on the walls. 

[zach_munce]

On 18/09/2023 at 11:23, ultra said:

Sorry just had them taken off and they are damaged on the walls. 

allgood selling it this weekend anyway

[tortron]

20 minutes ago, zach_munce said:

allgood selling it this weekend anyway

The happiest day of GN ownership

[zach_munce]

22 hours ago, tortron said:

The happiest day of GN ownership

haha going to my poppa so will still see it around fairly often and can still ride it myself

[flyingbrick]

what are you replacing it with?

 

[zach_munce]

On 06/10/2023 at 14:26, flyingbrick said:

what are you replacing it with?

 

most likely a 09 250r but funny you asked i found 2 more gn125 farm bikes for 800 {for both} kinda tempting i actually love how they ride so might finally get round to that dr200 swap if i do get those

[zach_munce]

Was at my Nana and poppas today and my poppa gave the mighty gn to me so now I'm wondering how much is reg and wof (if bike have wof) and what's the deal with re-registering a bike cus turners sells their bike deregistered

[Muncie]

You forgot the bit about it been completely restored to basically as new

[Muncie]

It's bloody miiiiiiiiint!

[zach_munce]

definitely. cant leave poppa with anything without him making it absolutely mint there was a chip on the side cover and he did a better job with a spray can than dad did with spray gun bloody impressive

[zach_munce]

Was thinking of doing some little mods to the gn. I want to put the super trap off dad's old project as people don't really see me when I'm riding cause it's so quiet, apparently a lt230 cam will fit but there's a slight difference. Is the worm gear for the Rev counter? Also is it really worth it 

Pic of each cam 

 

 

[tortron]

I am using thr hotcams lt230 race cam. There's a couple.levels

 

The worm gear is for the rev counter. I converted to electric gauge.

A dr200 cam is a good easy to get upgrade, it's a little less duration than the hotcam I have. The higher stages needed upgraded valve gear (that they also sell) but might have wanted a modified piston.

 

I would do the cam over a china big bore, in my testing they put out about the same power difference but the cam is more.reliable.

Also I ordered several aliexpress race cars and they either never showed up or were standard cams

 

 

 

[zach_munce]

So if I want more power kind of easier kind of cheaply just go normal dr200 cam?

[tortron]

Yeah, do that, probably drop the 0-100 time by 5 seconds

[zach_munce]

Oh mean will definitely do that

[zach_munce]

Would porting the head do anything or is there really no point?

[tortron]

I looked at it, it's about as good as it will get tbh. I did some port polishing and knife edged the guides which didn't do any seat of the pants improvements.

The dr125 heads have bigger valves and a slightly different port angle (they use the big knuckle dome type piston) and although on paper they put out the same power, it feels it flows better in the high rpm to me. The ideal head is apparently the LT185 quad head as its got the biggest valves and some other stuff. But if you have a flat top piston gn then you lose compression ratio and need to swap to a high dome piston. I currently have a dr125 head on mine, I was doing some tests with the 150 kit and some different pistons, it was promising but they all lacked due to not a big enough dome.

You could go a couple mm bigger on the intake valve, I have been meaning to do and test it, I did all the measurements and it should be a good little upgrade.

 

The ports were pretty clean, I just did 120 grit and mirror polished the combustion chamber, piston dome, shaped the valve guides and clocked the spark plug to point to the intake valve.

Something to do if the engines apart otherwise I wouldn't bother.

If you do the dr200 cam (or hotcam) and a direct pull pumper carb you will have a nice snappy response and a noticeable increase in acceleration (not really any top speed increase tho). The other thing that made a big difference was I changed the rear wheel to an 18" from a gt125, I mainly did it for tyre choice,but I guess the overall difference in weight of the wheel and tyre made a big change to how the bike reved up. It also turns in better imo.

 

(All the old dr125 engines are rooted, good luck. I mainly wanted an old one as they have an extra gear and kick start)