Overheating and oil questions

**Henk** · 20th December 2010, 19:46

Originally Posted by F5 Dave

CBR 125 with 150 top end.

hope you've changed the jetting & timing to cope with those changes.

time to dig out a carby,

Good point. Remapping the stock fool injection might be a bit tricky. Time for a power commander and some time on a dyno I suspect.

**Moooools** · 20th December 2010, 20:17

Originally Posted by Henk

Good point. Remapping the stock fool injection might be a bit tricky. Time for a power commander and some time on a dyno I suspect.

He has done the power commander and dyno. Don't really know how long he spent on the dyno though.

**koba** · 20th December 2010, 21:34

Originally Posted by F5 Dave

CBR 125 with 150 top end.

hope you've changed the jetting & timing to cope with those changes.

time to dig out a carby,

Compressionage too. And cam timing.

**all4A50s** · 20th December 2010, 22:21

Originally Posted by Moooools

He has done the power commander and dyno. Don't really know how long he spent on the dyno though.

Unfortunately only got an hour on a Dyno, which was enough to see what the power curve and AFR were doing. I'm trying out two directions with the mapping one based around a CBR125 map and one based around the Dyno readings.

**LBD** · 21st December 2010, 03:24

A lower viscosity oil (5 or 10W40)will generate less heat than a higher Viscosity 20W40)....

Any Synthetic will be better than any Mineral at coping with heat.

If you are producing much more power than std you will be producing more heat. If an oil cooler is to difficult how about a bigger radiator ?

I need to read up on race track rules on coolant me thinks....

A higher pressure cap will maintain a higher pressure in the cooling system and lift the boil point a little

**richban** · 21st December 2010, 06:14

Originally Posted by all4A50s

Unfortunately only got an hour on a Dyno, which was enough to see what the power curve and AFR were doing. I'm trying out two directions with the mapping one based around a CBR125 map and one based around the Dyno readings.

Looks a touch to lean at the top and to rich in the middle. Looks like more power to be had quite easily with some fueling. AFR to be in the safe zone at full throttle should be closer to 12.9. If the bike lives on full like most buckets then that could be your extra heat. And you say it all goes wrong the hotter it gets. Lean maybe. Double Ester Motul has served me well.

**Bert** · 21st December 2010, 06:55

thermostat; broken pump blades, lean.

Id also check that the 150 barrel actually lines up with the bottom end; i.e that the ports for the water jacket aren't blocked (half blocked) etc or full of silicon

Oil: AMPS (ducks nuts mate).

You wouldn't have this problem with a two stroke....