421 cheetah help

[alex2218]

I can say the map is perfectly designed to get the maximum HP because i know with a little more it's detonating, also, with less advance i can fell less power.
Okay it's nothing like a dyno but there is no dyno close to my home. The map as been designed according with an other map designed on dyno from a friend with the same engine / exhausts / carbs.
And his engine is heating too so he tried to change stinger size... but 23mm was supposed to be the best

If you lower the advance, the exhaust gas temperature is rising as you virtually blow the performance through the pipe

Totally true

Actually the impeller is a chariot performance and cannot be bigger because it's 0.1mm clearance from the pump cover

I can't go for a thicker rad but maybe a CBR 600 F1 one with 3 more rows...

Changing the flow is interesting, do you really think it's going to change anything Martin ?
I mean, its going to heat anyway from the top or from the bottom
Also i don't know how you want to do this since the INLET is always on the bottom of the rad and outlet must be on top of the rad

[MK]

I wasn't referring to the rad but to the head.

Route the hose outlet from the pump to the thermostat on the head.
And then connect the old head inlet to the rad inlet - voila, you inverted the head flow.

[(F5)]

The cooling flow is pants anyway. Its like aiming a hose into a bucket with a lid on and putting the overflow at the other edge of the lid. Better if it entered at the back of the barrel with a virtually sealed off head, was forced past the bores and ex port before then entering the head at the front and exiting the rear top.

But its a bit hard to change that now. I too have limited rad space. I nodded mine so it the water is forced from the top 1\2 of the RH rad tank to the left, it travels down the left tank and then exits out the bottom right.
Saw, insert and spot weld a plate to separate the top and bottom, best you can. Then swap exit over to other side. . . actually exit is on that side, I swapped the inlet. . .

[alex2218]

Hi guys,

Just tried new ignition maps, i lost some power at high revs by reducing the advance between 9k and 11k but i gained 10° so it's now 58°C when runninng hard.
Do you think i'm overheating at high revs when i use a map with maximum power because i may have a too hot plug ?

I'm using BR9ECMIX spark plug and this is what i got yesterday with a reduced advance map at high revs, actually it is rich, it's because i run safe during tests :
(I noticed spark plug are leaner with the powerfull map)

20170513_182352.jpg (196.34 KiB) Viewed 1041 times

So i want to get back my lost HP at high revs and i would know if using a racing spark plug like a 7376-10 will change anything because i fear it will be too cold.
It may be a cooling rad issue too but i know the spark plug can change lot of things and the rad is already much bigger thank stock.