O.S. No.7 Short Body Standard Glow Plug "Medium Hot"
About this part
This is an O.S. #7 Glow Plug. Recently developed to focus on easier running at low and medium speeds, this plug is a slightly hotter heat range than the O.S. #8 plug. This plug is ideal for helicopter engines with superior performance around hovering RPM range, which is critical for smooth and powerful 3D and F3C type flight. Also great all around plug for most 2-stroke standard plug airplane, helicopter and car engines.
| Model | Heat Range | Description |
| No.6 | Hot | Formerly known as the OS A3 plug. This hot plug will provide a more stable idle and crisp acceleration when compared to a cold plug. This plug is recommended for low nitro content fuels and .12 class engines. |
| No.7 | Medium Hot | Slightly "hotter" than the #8 and ideal for the constant "on/off" throttle action in 1/10 and 1/8 scale racing. |
| No.8 | Medium | A medium heat range plug for 1/8 scale racing and most .12-21 car, boat and truck engines. |
| No.10 | Cold | Formerly known as the OS A5 plug. This is now rated as a cold plug and is recommended for high nitro content fuel. This cold plug will produce the most power, but will provide a less stable idle and a narrow tuning window |
Reviews4.3 · 6 reviews
Very good glow plug for low & high rpms. Also grade idle in my engine. I use it in my savage with 5.9 engine & power master 25% fuel. Engine works 100-110c with body shell & many time to play. Exterior temperature in my place was 20c. Better from os no.8 in that engine.
Excellent with 16% nitro on hot weather with GX-21
Exactly as described and fast shipping as always!Great product!O.S is where it's at!
These are amazing for small engines (.12-.15) running higher nitro content or that like to cut out in colder temps at idle. Seems that these give a better idle than the 8 at the expense of a little top end.
I have been using these plugs in my SH.28 and works fine. Holds idle well good power range too. I cant tell the difference from the No:8 and this except the price..
Six reviews, mostly for the Medium Hot standard-body plug. Five rate it 5/5 and report good idle, stable tuning and solid power across rpm range, including in hot weather with higher nitro fuel and in small engines such as .12-.15 size. One reviewer says it gives a better idle than the No.8 at the cost of a little top end, and another says it performs like the No.8 and differs mainly in price. One 1/5 rating accompanies a text that describes the plug as working fine, so the rating appears inconsistent with the review body. No recurring problems are reported.
- + Holds idle well
- + Good power range across rpm
- + Performs well in hot weather with higher nitro
- + Suited to small engines
- − Slight loss of top end compared with No.8
- − Little difference from No.8 apart from price