I would like to turn this thread in to something that can be very useful for anyone with a 7.5 Tunnel. Information on stock or modified 7.5cc engines can be shared here as well as all the tunnels available on the market.
I'll start with my DPI 33" Tunnel that I have owned for a little over 4 years after purchasing it used, and it is still my absolute favourite boat.
It sports a K&B with a Silver Bullet pipe from HTBboats, muffler and prop shaft rebuild kit from www.ovalexpressracing.com
, Hitec 5645 steering servo, futaba S3004 throttle servo, 4+8oz tank, failsafe and 4 cell 4.8v receiver battery. I'm pretty happy with this setup. Using 25% nitro and a Prather 230, I'm in the low 40's. I'll have an accurate GPS figure soon to come.
Here are a couple photos. I hope together we will come up with a very valuable thread and shed some more light on the 7.5 OB class.