jonway overheating By daven68 (Read 8,155 times)

[JR]

Again Cruiser hit the nail on the head, I should have seen the GY-6 thing and said something. Ebay and other sites just like he said sometimes put the GY-6 on everything. No such a thing as a GY-6 250. Some of us have ordered stuff so long that we just know what is and what isn't. Main thing is with this scooter knowing the engine type and going from there.

JR

[tvnacman]

I would look to see if your getting any oil/water mix (head gasket) . Pull the plug and check , I maybe way off but no reason to leave a stone unturned . If you can see in the radiator see if you have flow . double check the cooling fan is spinning in the correct direction . use a garden hose and reverse flush the system .

I'm leaning toward burping .

John

[tvnacman]

No one likes the yankee's thoughts/ideas

[cruiser]

Apr 27, 2012 11:49:43 GMT -6 tvnacman said:

No one likes the yankee's thoughts/ideas

Would you like to clarify this post, John?

[tvnacman]

Apr 27, 2012 21:10:16 GMT -6 cruiser said:

Apr 27, 2012 11:49:43 GMT -6 tvnacman said:

No one likes the yankee's thoughts/ideas

Would you like to clarify this post, John?

Just being a wise guy
nothing to do with you being that I'm from NY and was refering to myself .

John

[imnts2]

Did I miss something? JR is right about the need to burp this scoot. Getting all the air out of the engine is critical. Any air is likely to remain and create a hot spot that Will generate steam and stop the circulation of water.
Since this scoot has a bit of history of overheating (and fan not working) and since it idles and runs as low speed without overheating, I wonder if the problem is not a defective radiator or a water pump not really pumping well.
I think I would remove the radiator and determine if some of the passages are not blocked. Also make sure air flow is not partly restricted.
A compression check would not hurt just to try to ensure the engine does not have a problem.
And read the plugs. a little lean fuel/air ratio increases the cooling load under part and full throttle a lot.

I suspect you really need a good cooling mechanic to work through the Long list of things that can cause overheating.

[daven68]

Here I go again, hottest scooter on 2 wheels. Over heating has improved but still running too hot.
Here`s what we did so far, removed the thermostat ( i know some of you had recommended against it, but by the time I got that post the bike was almost back together so thought I would just try it to see, I`m trying to juggle this repair around work. I do have a new thermostat in the waiting) . Flushed the radiator by forcing water through the radiator cap neck and disconnecting the hose at the water pump. did not see a clear way to flush the water pump though. refilled with dexcool and burped, saw air bubbles and a drop in levels but no gurgling . repeated this and topped off. took on a decent ride and temp stayed around 1/2 way or a little below. took a hard ride up a steep mountain about 2 miles straight up. heated up to over 3/4 , but did not redline. cooled to 1/2 on the way back down. stayed between 1/2 and 3/4 for the ride back. coolant level had dropped about 1 cups worth when i got back , topped off again. My friend , scootforfun, who is working on this with me has a theory. One thing I forgot to mention is that , last year, when the radiator fan originally crapped out the mechanic I was using had the bike for a month and then said he could not find a fan for it . Since I did not know better at that time I believed him and allowed him to cut out the front grill and install this huge aftermarket car fan in it`s place wired to a toggle switch. It sounds very similar to an air raid siren when engaged, and it worked to a degree, but never cooled properly and the bike always ran about 3/4 temp even at idle. now the new fan is installed but scootforfun thinks the big fan in front is possibly blocking the airflow from reaching the radiator at high speeds. I could remove it , leaving a big gaping hole where the grill used to be , if this would help. What do you guys think??

Also, when the scooter was in the shop when this all began one of the things he was supposed to do was a compression test to check for a head gasket leak. He said he did and it was fine, but I have no way to verify this.

[JR]

3 things come to mind, the first is your mechanic didn't know what he was doing and I would get a compression gauge and verify it one way or another myself. If the head gasket is on the way out it could be seeping, any milky looking oil?

Second thing is the first fan has got to go for two reasons, one it is interfering and second if you even try to use it you'll have a dead battery soon. It is not doing any good and is for sure hurting the real fan on the radiator.

Third on your new fan did you check to see what direction it is moving the air? It must pull the air through the front of the radiator and not push air through the radiator toward the front of the scooter. If it is running the wrong way it's vertually useless. Can change direction by simply reversing the wires. Also even Cruiser can tell you there are better, higher CFM fans out there that actually pull less amps. The fan that is used on the sister scooter the linhai pulls about half the amps and puts out more CFM.

Also since you mentioned running it and then topping it off again after it cooled just verified air in the system and there are those that will tell you sometimes it a 3 or 4 time process to get it all out.

Lastly I'll say this one more time, it will run hotter without the thermostat.

JR

[JR]

BTW you still have issues here:

thescooterprofessor.proboards.com/index.cgi?action=display&board=250classchinese&thread=1370&page=1

[daven68]

Hey JR, again thanks for your patience and help. I would love to take this thing to a good mechanic if I could find one and afford it but alas I`m on my own with the exception of scootforfuns help which has been invaluable but we are reaching the limits of his knowledge as well.
To be honest I would not know how to do a compression check however I changed the oil a couple of weeks ago and checked it today and it looks clear and clean.
So basically you agree with scootforfun in that the old fan is blocking airflow to the radiator?
And that plus the lack of the thermostat is what you believe is causing the high temps?
I`d really hate to tear that thing apart again but if I have to I will. Like I said , had I gotten to read your post before I was almost rebuilt I would have replaced it but we were so close to being reassembled I thought we`d give it a try. I did order one after I read it just in case. looks like i`ll need it after all.
Also , i`m curious about the water pump. when I look under the radiator cap i can`t see an actual flow of coolant . should I be able to? However the level does go up and down. Of course this could all be a moot point if I cant get the electrical problem figured out. Starting to look like next summer before I get back on the road.

[JR]

The cooling systems to say the least can be very frustrating on these scooters. Yes my friend you've got to tear it apart again and don't get discouraged. When you said the levels were going up and down and it is now trying to run cool it now tells me you're on the right track.

A recent member here with a linhai 300 almost wanted to pull his hair out until he finally got her to burp. Now she runs as cool as a cucumber.

A list;

Strip it
remove front fan
check new fan and make sure it is "pulling" air from front of scooter through the radiator out the back
install thermostat
fill and burp, fill and burp

look at front of scooter behind the headlight area for a remote alarm module, it will have a little horn by it like this;



It will have a ton of wires going into it and a plug. unplug it.

If you find not remote then it's time to start tracing the black wire off of the CDI and seeing if it has crossed or fused together with the red wire off of the R/R.

The R/R should have 6 wires

3 yellows
red
black
green

JR

[daven68]

Thanks again JR, we will look into this and I`ll strip it down again. may be a few days but maybe i can snap a couple of pictures too. starting to think it would be easier and cooler to leave the body off, remount the seat and just ride around on the frame. ;D

[cruiser]

If you are running without a thermostat, then you will always see coolant flow because there is no restriction. The thermostat slows the flow of water enough to allow the airflow through the radiator to remove the heat. Here's a replacement fan that a lot of guys, including me, have used:

.siliconeintakes.com/product_info.php?cPath=15&products_id=1024&osCsid=2bf68d71e32fe413cbb745cbd96ddb55" rel="nofollow" target="_blank">.siliconeintakes.com/product_info.php?cPath=15&products_id=1024&osCsid=2bf68d71e32fe413cbb745cbd96ddb55

[daven68]

Hey Cruiser , that looks to be the exact fan the mechanic put on there. will have to check when it`s apart to see if it`s blowing in the right direction. From looking into the neck under the rad cap I really can`t see any noticable movement other than the rising and falling of the level. So are you saying Without the thermostat I should see an actual current of moving coolant swirling around? If thats the case maybe im looking at a waterpump issue as well? Where will this ever end?

[billy22]

hi not sure how to use this site . However here goes I have a Yamaha 2001 250 majesty with 12 thousand miles on the clock which is true. It was ok at first say 500 miles .now I have a overheating problem. It runs ok the temp shows just below half way. when I come to stop the engine the temp goes in to the red and stays there to cool.I have a new thermostat new coolant fan but no power coming to the fan.What to test next any ideas would be great thank you   billy 22