Pulse adrenaline cruising speed?

**Pulse125** · 11-18-2012, 11:39 AM

Hello there new to the forum and just passed my CBT yesterday and I am looking into the pulse adrenaline for commuting to work. What would you say the maximum cruising speed is? Also I don't mind doing a few mods to it e.g. Exhaust, sprocket to increase the max speed

Thanks Ross

**spencer2004** · 11-20-2012, 04:39 PM

Without mods about 60mph, with mods about 70mph, even higher on a good day.

**Pulse125** · 11-20-2012, 06:03 PM

Ok thank you for the reply

**Pulse125** · 11-20-2012, 06:04 PM

Also do you think the 150cc big bore kit improves the top end much?

**spencer2004** · 11-25-2012, 10:45 PM

TLDR version: with the addition of a bigger carb and a larger front sprocket, a little

Long version: On it's own it ruins the top end since the intake will no longer be wide enough to supply enough fuel and air to get the engine up to 10k RPM, for 20% extra capacity you get 20% less RPMs. However the engine will still be producing more torque at the same RPMs as before so you can take advantage of that and fit a bigger front sprocket and/or a smaller rear sprocket which will change your gearing so you can do more speed per RPM. I changed my front sprocket from a 15 tooth to a 17 tooth so now I can do 70mph at 7k rpm and if I'm very lucky 80mph at 8k RPM so the reduced RPM limit is holding me back so much. It is however massively over gearing so 60 - 70mph is very slow and the speed is very very dependant on which way the wind is blowing.

I partially overcame the air flow restriction by fitting a bigger carb going from a 22mm to a 26mm which game me an extra 500 to the rpm limit which is an extra 5mph. The only other options are a bit more extreme but would have the most effect; firstly a performance camshaft with a longer duration would help with the airflow restriction, I have one that I got a while ago but I am too lazy to fit it so I don't even know if it would work. Porting the intake on the cylinder head would also help a bit and it would probably be fairly easy to do as it's a single cylinder engine. Ultimately the size of the valves are going to be holding the RPMs back, apparently you can stick the 200cc cylinder head on it with some modification but that's a bit extreme.