One significant difference between the two times you mention is that the float bowl would have been empty the first and full the second. The first time fuel would have rushed in, allowing a bit more to work up into the throttle body through the jets, thereby enriching the mixture for an easier start. The second time the fuel just kind of sat there leaving the mixture too lean, especially if you haven't drilled out the starter jet yet.*
This is why some folks have gotten into the ritual of running their float bowls dry before turning the bike off.

 

Duncan, interesting thought, but I can't see any way the t-bob would have any influence on cold starting whatsoever.

 

Dear TNC: With the TB kit, coolant flow is completely unrestricted when the bike is cold. It comes out of the coolant pump, flows into the cylinder base, up through the cyl. water jacket, into the cyl. head, out of head where the stock thermostat USED TO BE, up to the bypass junction and directly back to the intake side of the water pump. Until it's warm, the radiators and the relocated thermostat are not part of the coolant flow. It's a really well thought out and developed system. You really should go to Thermo-Bob's page for a decent description. Very cool stuff. If you have questions, phone him. I did. A nice guy. And smart.

 

TNC: What I neglected to do was to describe what the stock cooling sys. does when it's cold. Coolant comes from the output side of the pump and into the cyl. base. It then goes up through the cyl. coolant jacket, into the cyl. head and then to the thermostat on the left side of the head...then it STOPS! That closed thermostat is the plug at the end of the pipe. It takes a very, very long time to open because there is NO FLOW OF COOLANT THROUGH THE THERMOSTAT! NONE. Oh, I'm sorry. The micro bleed hole in the thermostat does let a few drips through. Go to Thermo-Bob's page. There are drawings of the sys. and it's flow path.

 

I agree with TNC. The t-bob will help with a rapid warmup etc.

 

Wouldn't the bike warm up quicker if the coolant was not flowing?
Tbob or no Tbob, no difference in starting.

 

Yes, cooling system would have no bearing on cold starts. Assuming spark & adequate charge, it's a mixture problem.

 

Info re Thermo-Bob:

Information, Articles

explains the working of T B

edit: this link may be better

http://shop.watt-man.com/Thermo-Bob-...-NEWER-TBX.htm

 

Go-cytosis: I guess I wasn't clear. I'm suggesting that because the output side of the coolant pump is blocked shut when cold, the pump is causing a drag on the motor. You know, FRICTIONAL LOSSES. This has NOTHING to do with warm up. Let me put it this way: The blocked output of a water pump will create a power ( you know, like HORSEPOWER ) loss greater than the power gain of an aftermarket muffler. You are incorrect, Sir. The coolant sys has a large bearing on cold starts. Remember, FRICTIONAL LOSSES.

 

Water pumps used on engines (and for irrigation) are mostly centrifugal type therefore not positive displacement and will not create excessive pressure under low flow conditions.
A hydraulic pump which uses a positive displacement gear or vane pump will load up if flow is restricted creating pressure.