i'd play it safe & put in the 2 copper & 1 alloy till you know how the pinch is, then take out 1 copper when the stress has been relieved off the piston. jmo

i'd also replace the rod if you haven't already

I replaced rod and big bearing.

Thanks Magpie.

let me know what you need and ill ship it your way.
starter box, clutch shoes, springs, flywheel, 3 ports , 5 ports, 7 ports, glow plugs, any shim screw or engine part, rods rebuild kits ect call me @ 214-779-1824 Wes. for info or email [email protected]

Hi Guys,

I have a gx 5prt in a truggy. Today went and did some practice and the first tank it ran ok. Second tank and it wouldnt run as soon as i went over 1/2 throttle it bogged heavily. So i leaned the HS needle 1 hr same went another hour better another hr better again and still good smoke, but everytime i top up the tank it runs boggy once i go for full throttle. Any ideas?

just keep going 1 hr lean until no problem!...also try NOT to let the fuel tank SNAP SHUT!...cause that alone will push fuel into motor and cause it to run rich

there's not a 1/2 tank lean issue with the gx5r or 7r is there?

nope

BIG SIGH OF RELEIF.

1/2 tank lean isn't a symptom of any particular engine. This symptom is caused by fuel tank height/shape of some manufacturers. For example, the HPI Savage has exhibited this symptom since it's introduction. I could give you a long, drawn out, explanation as to why this happens. Here's the short version. If you examine your fuel system closely, you'll see than at a certain fuel tank level the fuel has to be forced upwards to your carb's fuel nipple. The lower the fuel level is, the more pressure it takes to move it up to the carb. This causes a slight leaning of your mixture.

Tune with your engine at full temp, while the fuel tank is low, and you'll never "lean out" when the fuel tank level becomes low.

which carb insert is better for top end???

8.0mm but you WILL lose run time compared to the 7.0mm

so which one is the best for bottem end???

6.5

Basically the bigger restrictor (8mm) will give you more of everything except economy. So if you want raw power and have no concerns about run time or smooth power control, the 8 mm is the ticket.

Conversly the 6.5mm restrictor will give you a much smoother motor. You still get good power, but itīs not as brutal as the 8mm and you will get better run times. You will loose a little bit of top end, just by the nature or the smaller inlet size restricting total air flow into the motor. On some tracks it does seem as though the 6.5 mm restrictor actually boosts bottom end repsonse at partial throttle openings, due to a ram air effect caused by the more tapered throat of the smaller restrictor, but this effect is pretty negligible.

Most people go for the 7mm in truggy, which gives a nice compromise between power, smoothness and economy.
Buggy either 7mm or normally 6.5mm. Most buggy drivers like the smoother power of the smaller restrictor, plus the added run times with the buggy gearing. The power offered by the bigger restrictors is normally lost in wheelspin and lack of control in a buggy.

Great sumation Grizz