Tri-z Runs Hot. What's with that?

[Just-Tri-It]

My Z is still on the stock bore and setup. I put the DG exhaust on it. I noticed a few things that I need to adjust.
It seems to get better top end but some of the low end grunt is gone and it tries to bog a little at take off.
If I do several donuts at low speed it tends to run hot because the red light comes on.
I haven't adjusted the main jets up any at this point but that may be part of the trouble. But it runs good out side of that.
It had plenty coolant and the pump seems to be working. It only seems to run hot after I stop running up and down hills and start the donuts.
The plug is brownish but not very wet when I inspect it.
Anyone running stock motor with the dg exhaust and have had this problem?
Thanks

[MTS]

How dose the idle sound when its hot? Steady low consistant..or ring a ting ting up and down? rad fins good and straight? Puking out the overflow?

[CRAZY70MAN]

Are you running a thermostat? Have you ever replaced or inspected waterpump impeller? It could have gotten hot and is not spinning now all the time? Try taking the thermostat out or at least testing it if you leave it in.

[Mosh]

Call me crazy, but doing long extended periods of donuts with no airflow over the rads, is going to make anything run hot.

[fabiodriven]

The Z's have obvious cooling issues that need to be addressed, but let me ask you this- Did you jet it for the DG pipe when you put that on there?

You mentioned changing the pipe but you never said you jetted the bike after that. You also mentioned the bogging off-idle. Very typical symptoms of improper jetting. I would imagine a lean motor would also run a lot hotter as well.


Call me crazy, but doing long extended periods of donuts with no airflow over the rads, is going to make anything run hot.

Except a first-gen Tecate! But then again, not everyone can have pickup truck sized radiators. :D

[Just-Tri-It]

The Z's have obvious cooling issues that need to be addressed, but let me ask you this- Did you jet it for the DG pipe when you put that on there?

You mentioned changing the pipe but you never said you jetted the bike after that. You also mentioned the bogging off-idle. Very typical symptoms of improper jetting. I would imagine a lean motor would also run a lot hotter as well.



Except a first-gen Tecate! But then again, not everyone can have pickup truck sized radiators. :D
I didn't jet it bigger till last night. Went up from 470 to a 480. And may go higher. Any idea what would be the highest it could take on a stock bore cylinder? That was the largest I have till I can pick up some more.

[Just-Tri-It]

Call me crazy, but doing long extended periods of donuts with no airflow over the rads, is going to make anything run hot.
You may have a point there as well.

[Just-Tri-It]

Are you running a thermostat? Have you ever replaced or inspected waterpump impeller? It could have gotten hot and is not spinning now all the time? Try taking the thermostat out or at least testing it if you leave it in.
I think the thermo is still in it. May just take it out till I can get a new one and see if it helps...or just replce it with a new one while I have it down.

[Just-Tri-It]

How dose the idle sound when its hot? Steady low consistant..or ring a ting ting up and down? rad fins good and straight? Puking out the overflow?
I will idle well and not go dead. But it does ping some when the light comes on. That's how I knew it was running hot before I noticed the light.

[Mosh]

Tri-Z's with stock carbs are jetted rich from the factory. Even if you put a DG pipe on with aftermarket reeds, and pull the airbox lid, you would be fine and still a fuzz rich, more than likely. Alot of Z guys with stock carbs will tell you that they actually need jetted down. My ported z with a coolhead and reeds and pipe ran stock jetting in the 85 carb, and was a tad rich .