Am I too cool?

[irk_miller]

On my RD350 that's been converted to LC, I am running an electric coolant pump with no thermostat, but switched through the right handlebar controls.  If I let it run from start up all through riding, I am sitting in mid 160s in the summer and so far mid 140s in the winter.  I have also noticed more bog during early, cooler parts of my runs since winter started.  (I am in Georgia, so the notion of winter is up for debate) 

I am curious, generally speaking, if I am hurting performance by keeping it too cool.  Power still feels like it's there, but I haven't been able to consistently keep it between 180 and 210 with the switch, so I typically just run it switched on and keep the temps where they are. It's my thoughts that I am probably burning less off and that's contributing to increased early bog, and possibly affecting atomization or the something I don't know enough about throughout my rides. 

[teazer]

I suspect that there are two different forces at play here.  140F is about right for peak performance and 160 is OK.  But in the colder weather you may find that your jetting is a little rich for the ambient conditions.

[m in sc]

i never run my fan and i'm usually settled in around 170f measuring out of the top hose of the head on the LC. anything under 125 it will bog down low sometimes, and on real raucus runs i'll hit 190 or so, but rare and that's in the summer.  id recommend a thermostatic switch for the fan. .02

[rodneya]

Adjusting your air screws should help with some of the cold days bogging as long as you take time to warm up for a few minutes before riding.

[irk_miller]

i never run my fan and i'm usually settled in around 170f measuring out of the top hose of the head on the LC. anything under 125 it will bog down low sometimes, and on real raucus runs i'll hit 190 or so, but rare and that's in the summer.  id recommend a thermostatic switch for the fan. .02

Appreciate the feedback. 

m in sc, I don't have a fan at all. I think you misread me. I am shutting down the pump to let the bike heat up, so a thermostat would turn the pump on and off, not a fan. I don't think a pump should turn on and off, personally, so my lead was to figure out if I am good running at the temps the pump keeps it at but maybe get some other information from you guys that know so much more about these engines. The reason I switched the pump at all was to get quicker heat up times and an emergency shut off in case something happens with the tiny 2.3 Ah battery on a ride. 

[m in sc]

thats' right....
however, it actually may not be a bad idea to control the pump w a thermostatic switch, its not going to hurt anything. you're basically doing the same thing now, just manually. the one i had w an electric pump used to take a while to warm up as well, longer than the mechanical pump.. for obvious reasons.   

another thought , have you considered an actual thermostat in the water neck?  the rzs and my tzr has them.

[rodneya]

You can get an inline thermostat with a bypass made for cart motors with an external water pump. It keeps the water moving, but within the motor only until warm

[m in sc]

^ there you go, thats a great solution. 

[irk_miller]

Yessir!  Thank you.

[sav0r]

Maybe add an inline thermostat? You don't even need a bypass, you just let the pump cavitate.

Edit: lol, well I see that idea was mentioned as I left my post open since this morning. On our racing stuff we just drilled a hole in the thermostat to bleed some coolant. We never did the bypass.

[teazer]

Many TZ racers gutted the thermostat leaving only the outer ring, but they also make sure the bike is properly warmed up before a race.

[Vintagetz]

I have 3 of those bypass thermostats for my TZ and RZ's.  you can have a cold seizure.   It also manages a larger radiator which can be needed on hot days but can make the motor to cold on cold days.

[busa1300]

Tape over radiator or a restrictor in line somewhere to slow down water flow?
Less voltage to the motor to slow it down?

Just ideas.... Never had an electric pump on a bike.

[m in sc]

ive done both, mech and elec water pumps...all my experience ON A STREET BIKE with similar mods w the same cyls is that things don't start 'working' right until the water temp out of the head is -at least- 125 degrees.  optimal seems to be in the 160-180 range. on some hot rod cars with electric water pumps, ive seen a thermostatic switch used to control the pump. as soon as that pump starts flowing, it cools down very quick.  on the RD i did w an electric pump, i used a stock thin rz radiator that ran a bit warmer than the big aftermarket LC one i have on my LC, so it got up to temp quick ish. the downside to electric is that its full flow at any engine rpm.  theres multiple ways to deal with it, you just need to pick your poison.