From memory you run 20% yes ? The OD77T would be nice for 20% being a hotter plug than the 97T.
That P7 should be fine. Going cooler on the 20% fuel is not going to do any harm. Performance might suffer a little, I'm not sure, but you won't hurt anything.

Have you thought of changing up to 25 or 30% fuel with an OD 97T ? The Taiwanese motors seem to like the higher nitro content fuels, and I think you would find the performance increase quite pleasing.

that was the OS RP7 T cold plug, sorry :blush:

Gee you guys have been busy :lol: I just had to read 3 pages to catch up since my last visit !

Everything has been answered, so nothin for me to post. ;)

Tho I would like to say the MG66 in a truggy is sweeeeeeet too, there has been a lot of talk of the GX5 port in a truggy, yes it's good too but don't forget the MG as an option.

The US distributer is Answer RC USA.

yes I'v run a OS p7 in a pinch and worked quite fine...actually increased torque but the tune has to be spot on.

I recommend the Odonnel T97 med in all GO based engines, rather than the T77 hot, the only time I run the T77 is in a new engine for the first littre, then I go to the T97 and race tune the engine.

There was talk of long vs short bottom end needles again, I find the long needle type VERY easy to tune once you understand how to set it with the pinch method and then the only adjustment you need to make is from the top end. There is more on this on the MassiveMods web site.

Yeah - where have you been Flanno :p. Get with the times bro :lol:

That's what happens when you work shift work, come off a night shift and have most of the morning free to talk shop on here before you fall asleep :cool: Jeez, that reminds me, the other half wanted me to do something around the house this morning !!! Never mind, tomorrow is another day ;)

A lot happens in 24 hrs :D

At least I know there is someone else on here to help out if I'm at work ;)

I've converted mine to short needle. Its just easier as i've been running nitro for 10 years and have always been used to having and tuning with a short needle. Just for future reference how long does the needle need to be and how do you properly grind it down. Also should you retaper the needle once shortened or just leave it blunt? I just basically copied my other needle that was shortened by a professional go engine tech, but would like to know the specs for future use. I plan on running go engines from here on out on both my buggy and truggy and even have a spare on hand just in case.

i can get you a new short needle for $5.50...so you dont have to modify the 1s you have!

If you really want to change, just buy a short needle from deadmancourt, it's less hassle and you have the factory product.
But if you want to do your own thing, the original long needle is 1.6" with a fine taper. You need to shorten it to a finished length of 1.42". Leave the end rounded (I would call it "bull nosed" for want of a better description). The tip after you have trimmed it, will be close enough to the correct diameter, it just needs rounding off. No tapering or anything else required.
We did a few of these here until the factory short needles became available aftermarket. However most of the guys have now gone back to the long needle after getting some tuning tips.
These motors do have a nice powerband with the factory long needle fitted, and once you have the low speed needle and idle gap set using the 7 sec pinch method with both needles set flush to start with (before the motor warms up too much), you basically have a one needle carb (HSN), which makes it real easy :cool:
It's not difficult, just different. Worth a try, as they do run nice on the long needle.
All you have to remember, is if you get lean bog as the tank level drops you need to richen the HSN a screwdriver blade width at a time until the lean bog goes. Don't richen the bottom end like other (short needle) carbs. That's really the only difference.
In return you get a very smooth powerband from idle to WOT because the long tapered needle controls the fuel flow right through the entire rev range, with no transition tuning required around when (in a short needle carb) the HSN takes over from the LSN.

if anyone is looking for a cheap gx5r lmk. It has 14 tanks on it.=) ad ill include a 0801.

HOW CHEAP FOR THE GX5R?....as for the SHORT needle is there a pinch test number of seconds for this needle?....or is it the same 7 sec. as for the long needle?

pm sent:)

long needle = LSN plays a bigger role
short needle - HSN does...

Pretty much the same (5 - 7 sec). The pinch test gets you in the ball park for the bottom end tune. Perhaps the most important thing when doing the pinch test is setting the idle gap by the amount the motor spikes up in revs when you pinch off the fuel line.
As you know, the LSN is directly connected to the throttle slide, so getting the idle gap set right so the throttle slide (and LSN) are correctly positioned before you start tuning is paramount.
If the motor spikes up quite high in revs when you pinch off the line, you need to reduce the idle gap. What you want is a slow steady rise in revs (only 500 rpm or so) which will indicate the idle gap is correct. Now that the throttle slide is set in position you can tweak the LSN to get the 7 sec period before the motor dies, which indicates how rich or lean the LSN is set.
7 sec will put you in the ball park with a short or long needle carb.

I have found at 7 sec the LSN is still a little rich, but that is good, because when you set the HSN you invariably need to lean it some to get the crisp top end you require. Leaning the HSN will effectively lean the LSN too, so after you have set the top end, your 7 sec bottom end which was a little rich, will now be pretty close to spot on. Just fine tune if required.

The biggest difference with the short and long needles is the amount you will need to go in from flush on the HSN.
The long needle requires the HSN to be rich enough (flush or a couple of hours in) to let sufficient fuel past the longer needle which stays in the receiver jet even at full throttle - which is why you adjust the HSN to cure the lean bog on this carb as opposed to the LSN like normal.

The short needle will see the HSN some .5 - .75 turns or more in from flush, as on the short needle carb the HSN is totally controlling the amount of fuel the motor gets at full throttle as the LSN will have come completely out of the receiver jet at around 2/3 throttle (completely different to the long needle set up).

Jeez - sorry if it seems like I am rambling guys, but there is no short way of explaining this I don't think. Apologies to those who have read similar posts before, but hopefully people will read this and the light will come on for some of them as regards some aspects of tuning the different needle carbs.
Cheers :cool:

that is pretty much exactly how i tuned my gx5r and runs great!....screams on top and pulls like a tractor on bottom! and that was with a .4mm shim stack!....i pulled out the 2 copper .2mm shims and put in only the 1 alloy .3mm shim!...i havent had a chance to run it yet but it should be perfect with 20% and the od77t!.....wich is mind boggling cause it already ran like a bat out of hell!

+1

Explained well Grizz :nod: