Linhai OVERHEAT FRUSTRATED By rob00757 (Read 4,190 times)

[rob00757]

Ok, I am at my witts end on this. MC54B with linhai engine, put new radiator in with new fan sensor. Drained and coolant. Drained oil because that is what you do when you put in a NEW water pump. Even took off the right side cover where magneto is to get a look at the drive sproket that turns the water pump. The oil pump sproket drives the water pump sproket that is connected to a four inch shaft which is then connected to the water pump on the left side of engine. sprockets looked good and even spun the fly wheel to watch them both rotate as my wife observed the water pump blades rotate on the other side of the engine. So where does all this lead to? AN OVERHEATED ENGINE!!! I have taken out the thermostat, removed the water pump, blew compressed air up from the bottom where the coolant enters the engine(under cylinder by exhaust) and air blew out the thermostat hole, then did the same from the top. them blew from hose that connects to water pump as air gushed out the thermostat hose. blew air everywhere to make sure there were no clogs in the system. boiled the actual thermostat in suspended hot water. it checks out good. Filled system with coolant while small hose was disconnected from thermostat housing to let air escape. fired her up and watched with cap off. it seems to be backing up and overflowing the overflow bottle. The fan cycles on and off as it idles, but when i rev to 5000 and hold it, the fluid backs up and overflows the at the cap. then with cap on and i ride it the needle goes to red after about 15 mins of good hard riding and out it comes from the bottle. I suspected the water pump because the red lining was intermittant, like the pump was sometimes pumping throughout system. No cracked head or anything as i don't have coolant in oil. what is causing this overheating? Where to turn to next?? FRUSTRATED !!!

[Alleyoop]

Well it appears nobody seems to be able to help you, so I am going to send you to someone that has that same scoot and can help you. It is on another Scooter forum but like I said he has the same scoot and knows the cooling and electricals on your scoot.
The site is ScooterProfessor go and open up a thread with your problem.
Alleyoop

[rp]

Did you do anything to the scoot befor the overheating started? Valve adjustment, Carb adjustment, new plug??.
Just throwing it out there. RP

[rob00757]

O.K. thanks to all who read my troubles with overheating. As there was no coolant in the oil, i figured head was ok. but as i flused it with water, ran water from garden hose hooked up to the water pump intake and wham...white smoke out the back. so figured head is cracked or warped or something. so I called a guy and 20 minutes later I had in my possesion a newly rebuilt whole engine. 200 bucks and I am swapping them out. will use my old one ( with 22,757 miles on it for parts) hope to put 20,000 or more on this one too... happy scootin y'all......

[Cruiser]

Happy to hear that you pinned down the problem. Sounds like what I described in a PM that I sent to you on 4/5/2012.

[rob00757]

cruiser and alleyoop, thanks for the reply's on my troubles. I was unaware of the personal messages we can get on this site. I just happened to see i had messages so i clicked on them and wow, read each one. This is such a great resource, thanks to all who run and put this out. my new used engine works great after i swapped out the stator and magneto from my old one. Seems the new engine had the smaller stator that was incompatible with my electrical system. Now I will ride that thing daily. I have a question about breaking in a new engine. I read somewhere you shouldn't baby the engine, wide open from the start. any thoughts?

[Cruiser]

Your welcome, rob00757. Here is the Motoman method of breaking in a new engine.

www.mototuneusa.com/break_in_secrets.htm

He advocates the "hard break in" which I have used on my two scoots with success.