Losing power at 55 down to 40. Coolant full yet overheating

[GeorgeSK]

Interesting point, Mel. If the oil is really cruddy (and it sounds like it is!), then there is probably a number of places where there is build up that should not be there. New oil run for a hundred or so miles will act as a rinse.

Does anybody have any favorite additive that might help what I will call "temporary oil" do a better job of cleaning?

[springer1]

Does anybody have any favorite additive that might help what I will call "temporary oil" do a better job of cleaning?

Just change the oil again after 100 miles or so if you want, DON'T put any solvent or etc to intentionally loosen and circulate crud thru the engine and scar it up until you change it again. Will do more harm than good.

BTW, this is the same reason why if your older car/truck has run substantial miles (40k or more) with regular oil - you should NOT switch to synthetic. You'll loosen and circulate more crud than your filter can handle thru your engine until you change it again. I did this once and then pulled the oil filter after 50 miles or so because my buddy warned me (but too late). NO oil would drain from the filter, rather it was completely filled with heavy crud. I ended up changing the filter again every 100 miles 4 or 5 times before oil would finally drain from the filter. If you have been using dinosaur oil, stay using dinosaur oil - it's perfectly good lubricant.

[easyrider]

Marvel Mystery Oil

[alx123]

I would say the TPS sensor in the FI coz I had the same problem before. But mine didn't have that burning plastic smell and the overheat light on.

TPS in the FI?
Please elaborate and tell me how to check/fix if possible please.

here's the link discussing my TPS problem

https://www.hondapcx.org/viewtopic.php?f=19&t=9329

[springer1]

Those diagnostic tools are super in sorting thru FI & ignition issues - LoL a miracle of modern technology.

[maddiedog]

When I swapped the engine on my 125, I had the overheat light come on with the first ride. I didn't properly fill the coolant, so there was a bunch of air in the lines. Is it possible they tried to swap the coolant and didn't fill right, leaving a bunch of air in there?

I've seen a lot of good suggestions so far on oil -- I 2nd the recommendation to do another oil change after ~100 or so more miles. Any w30 synthetic should work great (0w30, 5w30, 10w30). Make sure you use synthetic though.

[mhallida]

Did you ever figure out way was causing the power loss. I currently have the same problem with my 2019

[Valeriy7]

Please tell me, if you close pipe 8 of the small cooling circle, will the coolant be colder, especially in the heat? In order not to open the constant cooling of the engine in a large circle. Thank you!