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937 Posts
Discussion Starter · #1 ·
First question is - does a reservoir tank that is overfull effect the cooling of the trike ?

I filled my overflow tank to the top of the neck by accident, not paying attention to it while filling, and I didn't take any out because I didn't think it would be a problem. It's easy to do, I was in a hurry and just buttoned it up and left for a ride. No problems occurred during the next two months.

I'll try to be as descriptive as I can because I want to solve this "problem" if I can.

The first time it happened when we were climbing up the twisty road to Jerome AZ in 95*. I attributed it to the fact that we were 2 up loaded down with an 8 day trip of stuff on a rack.

While on a 2 up ride yesterday, we were going up I-15 towards the high desert on a pretty steep grade at about 60-65 when the temp gauge started moving up from the just under half mark to the 3/4 mark. The OAT was 95*

I had plenty of airflow as we were moving in clear traffic but it was definitely heading north on the gauge. When we crested the hill onto a level stretch it went back down to it's normal position on the gauge. That was occurrence #1 for the day.

After we got off the freeway we were going up a mountain road with a lot of twisties going about 40-45 when the needle started to move up again slowly. The temps had gone down to 80*. On to a long flat stretch and it went back down.

Now we are going up a long straight steep incline and after a few miles the needle starts moving up again to the 3/4 mark.

Here is the odd part ! The rest of the day up at 5000'+ was spent driving through the mountain roads at low speeds (15-40 MPH) and low RPM's, through twisties, inclines, declines, sitting it traffic and the needle never moved from the normal position. The temps were in the low 80's.

When we came down the mountain we were met with 105* temps on the freeway ride home of 40 miles. The needle never moved from normal ! We had stop & go traffic and 70+mph sections and nothing changed.

I only seems to do this on a a steep incline when the engine is under a heavier load. The RPM's do not make a difference. I have tried lower RPM's - 2200-2500 and higher RPM's - 3200-3500 - no difference.

What could be causing this ? It has never puked coolant and it looks like the overflow has never been used because if it was it would have puked out the overfilled stuff I put in. The level is the same as it was when I overfilled it.

I've pulled the radiator cap and it is full to the top.

Any help is appreciated !


Firm Member
3,159 Posts
The reservoir has an overflow tube on it. Overfilling the reservoir will have no impact on the radiator or its cooling capacity.

Good Luck!
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