250 cc watercooled cooling problems By grbell1834 (Read 4,018 times)

[grbell1834]

Had to replace the CF Moto radiator cap, with another from a bike shop locally. The new cap had a higher spring tension than the original one supplied. The fellow at the store told me the new cap would help things to run cooler. The opposite seems to be true as the temp gage now runs all the way up to just a smidge under "hot". However, I cannot seem to get the radiator hot enough to trip the cooling fan on. I am afraid to run the run the thing without causing major damage to the engine? Could the fan sensor on the bottom of the radiator be defective? Don't know where I can obtain one of those. Does anybody know a source for the CF Moto radiator cap?

[JR]

First of all Welcome to the forum! Can you tell me which moto you have? Fashion V3 etc.?

We had a fellow just s pell back with the same issues and simply put it was air in the system. The slightest amount of air will make it run hot ........and cause the fan to not cycle as it should in fact most of the times it will not even come on.

Now here is my burping procedure for the linhai 257cc but it works well on other scooters;

thescooterprofessor.proboards.com/index.cgi?board=cool&action=display&thread=24

Now as far as the radiator sensor (it's actually a thermoswitch) we have manuals for all the motos and when you tell me what you have then we can look this up.

Don't know why he sold you and told you the higher pressure cap would be OK?

The cap needs to the right designed pressuer for the coolant to work in the reservoir tank properly. When the scooter warms up it may pull extra coolant from the reserve tank and when it cools it puts excess fluid back in the tank. If the cap pressure is too high then this will not function correctly.

Now on the fan you can test it by simply finding the radiator thermoswitch and jumping the wires together in most cases but again when I know which one you have I can tell more.

Now I'll look for cap but am in the dark with no knowledge of your model or engine. You may have to go to CF Motos website and find the closest dealer to you but lets see what we can find first.

Again get back to us and we're glad you're here!

JR

[grbell1834]

Thanks for the response. The China bike I bought (in 2006) was a BMS (Baron Motorcycle) and nameplate also indicates bike mfg by Shanghai JM Star Motorcycle Ltd. BMS is defunct and out of business. The radiator cap was a CF Moto2125 as stamped on the top of the cap. The inside diameter of the cap measures approx 2.9 cm's, and the outside diameter of the cap measures 4.5 cm's. The engine says 250 cc displacement. I can send photos if necessary. Thanks for the tip on the proper cap and working properly with the overflow reservoir. I'm sure I can return the one I purchased. I can send pic's if need be on any of this, ie cap, engine, etc.

[JR]

Then it has the wrong cap to start with? Did you buy this new or used? Yes please send some pics of the scooter and I'm sure we can help find a cap and fix this problem. Will be gone for a couple of hours and check back in later and we'll find a cap.

Once we get the correct cap then it's a matter or getting all the air out.

JR

[alleyoop]

Yea wrong cap might be to strong of pressure required to open.
Alleyoop

[grbell1834]

How does one attach photos on reply? I try to attach and then I get an error that I cannot post.

[alleyoop]

Are you using PHOTOBUCKET or some other Video or photo website? WE have a HOW-TO for photobucket on here ITS free and you can load up pictuers from you computer onto it and then copy and paste the link onto here and they will show up.
Alleyoop

thescooterprofessor.proboards.com/index.cgi?board=directory&action=display&thread=90

[grbell1834]

Ok, lets try these photos of engine and radiator,

[JR]

Nice pictures and for sure thats a 244cc CF Moto cloned or OEM engine. I'll have to look at the BMS 250 didn't know they used this engine.

Doesn't matter we now need to find the correct cap and burp it and I figure she'll be OK.

Now I can see the radiator and the fan thermoswitch down at the bottom in the third picture. Since we know we need to find the correct cap we can still test the fan. Unplug the two wires to this swtich jump them together and turn the key on and lets see if the fan comes on.

I've got to see if I got or have a manual for this scooter also. Does this scooter have a fuse box and a fan fuse? If so make sure the fues is good.

I'll get back as soon as I get some more info.

JR

[grbell1834]

The fan works, so no further need here. Probably have not gotten the temp high enough in the radiator for it to go on. We'll see what happens with new radiator cap, when you can find me the right one. Thanks.

[JR]

OK there are 3 basic body styles for the 06 Baron 250 type scooters and from what I'm seeing in your picture it looks like you have a 10" rear tire? If so then it's the 2006 Touring 250 which is a Bali, and tank look alike. Look at this site and click on the larger view of each of the 250's and tell me if that looks like your scooter?

.scooterpartspro.com/?sef_rewrite=1" rel="nofollow" target="_blank">.scooterpartspro.com/?sef_rewrite=1

Now this engine goes in several scooters and the radiator and cooling system parts are for the most part the same from one model to the next. Here is the cooling parts for this engine from a trusted friend and vendor who has a banner above:

absolutelyscooterparts.net/catalog/cn250-honda-based-244cc-c-1_16.html?osCsid=mfbf3la906u9klnt9tlsjtp421

As you can see he has the neck, theromoswitch and cap along with other cooling parts. He's a good guy, Dave and tell him what you have and he'll fix you up.

Tell him JR sent ya!

[grbell1834]

Here is picture of BMS Macho Man 250. Looks as if the rear whell measures 10 in on the radius. Thanks for the links, as it appears the source has the parts and the right parts. Next issue I have is with the ABS brakes on this and getting the fluid replaced and getting pressure to build, but I will take out a new thread on this issue.

[JR]

Yep tank. bali style scooter and a pretty one at that. Get the cap on and let's burp her and I'm betting she'll cool down and the fan will cycle.

JR

[grbell1834]

JR I received the correct radiator cap and new neck filler from your parts dealer up in Elgin, Ill. I have gone thru the burping exercise at least a few times now. The temp gague continues to run up toward hot, before I shut it down, let cool down, cycle and re-fill. The fan does not come on either. Got any further ideas? What is the function of the temperature device up near the carb? This device has a sensor for the temp gague on the instrument panel. That part seems to work ok, because if I disconnet the wire, there is no temp reading on the instrument panel gague. Does this part do anything else which could cause the temp to rise?

[JR]

OK we know the fan will work and if you got all the air out then it's one of two things, either a stuck thermostat or a bad waterpump.

Not trying to sound smart but sometimes even my burp takes several times. When you pull the cap and start it do you in a few minutes see the water level change like when the thermostat opens?

Also again not tring to sound smart you are letting the scooter go what I call bone cold before you pull the cap and check the level right?

I know if I remember runningslow saying he had to burp his about 5 times to expell all the air.
any air whatsoever will make it run hot and the fan not come on.

In answer to your other question the the device by the carb is indeed the temp gauge sensor and it's only function is to send the temp signal to the gauge.

Now you said shut it down and re-fill, if this is happening then it still has air in it, when al the air is gone you will not need to re-fill it at all.

I had another fellow have this problem once and he quickly filled his, put the cap on and took it for a quick spin around the block and got her circulating real well, shut it down and let it sit about 5 hours, came back filled it up and all was well.

Also no matter what anyone tells you do NOT run this scooter without a thermostat.

JR