250 Roketa 244cc cooling issue By mxmatt (Read 6,772 times)

[mxmatt]

Apr 30, 2016 18:17:20 GMT -6 Alleyoop said:

Don't know what happened but NO when I opened the thead it only showed the 1st page and I responded to that page. It did not show that it was novel and it had 5 more pages.

Why do I feel the urge to come up with some "Rich like" smart remark? ?

Thanks for all you help on this thread.

[billg71]

mxmatt,Bashan,JR,Guitarman,cyborg

I have a Lance Duke Touring 250 (244), with the same Honda Helix drive train. I responded to this thread as billg, but had to re apply as my old password no longer works.

I have an infra red thermometer and know how this works. Unlike the Helix, these Chinese scoots do not have the radiator capacity of the Helix. I went through a head gasket finding that out. I went so far as to dis- assemble my radiator to rod it out. That, or any circulation problem, was not the problem. These Chinese Helix clones will get up and do 70 on the freeway, but as soon as the oil heats up, the radiator is too small to keep up and you will kill the head gasket if you do it enough. Look up a product called K&S Fiberlock, available at WalMart. It will preserve your head gasket until you can solve your radiator capacity problem.

The solution is either more radiator capacity or an oil cooler, preferably more radiator capacity. Some have solved the problem with an additional radiator installed at the front of the frame, just behind the front wheel. That creates an additional problem of too much cooling capacity which they say effects gas mileage.

My first attempt will be installation of an additional fan in front of the radiator to increase air through the radiator at high temps. It will be wired through a toggle switch as well as through the existing thermostat so I can choose when it runs, as these electrical systems are minimal at best. Dumping the electrical carb enricher helps. It will require moving the radiator back toward the engine a few inches to make room for the additional fan, with all the pain that entails, but better than the pain of the piping to a whole 'nother' radiator. If that doesn't work, it'll be an oil cooler which will probably require an additional fan anyway.

[bob123456789]

MXMatt

Thanks for your insight. I learn something new every time I come here. Please keep all of updated as you do it so we can all learn and improve.

Have you considered replacing the existing fan with one with a higher volume (cubic feet per minute)? This could improve the situation and avoid having to deal with the tight spot and the fun of moving the radiator.

[billg71]

Replacing the existing fan with one with greater capacity is a great idea.  It's just that I can't find one that'll fit.  The existing fan mounts on the front of the radiator which is the side the hoses attach, limiting the diameter of the fan.  If you know of a higher capacity fan of the same diameter, I'd sure like to hear about it.

[bob123456789]

Do you know the diameter of the old one?

Is here any way to find out the cubic feet per minute (CFM) of the old one?

When I googled it I came across a couple of options in the US. This one has two options. Both are in the $125-$150 range. The lower price option doesn't list a CFM (it just says 25% more than stock) but the higher priced one does. It is 440 CFM. If you were interested in them I would contact the seller to get the dimensions.

www.mooseracing.com/search/?q=fan&submit=Search&docType=product

The other US based one is below. They don't have CFM or dimensions on the web site:

quadboss.com/radiator_cool_fan.html

Like anything with these scooters their probably is a cheaper Chinese option it you use www.Alibaba.com. I looked at a few and they were in the $25-$30 range, none I looked at had the CFM rating. Some time spent searching there might be really rewarded.

[bob123456789]

Here is another one on Amazon ($24):

www.amazon.com/Universal-Performance-Electric-Radiator-Mounting/dp/B00T3T7IJU/ref=cm_cr_arp_d_product_top?ie=UTF8

I'm not sure if the 7 inch diameter one fits in your application. It has a maximum cubic feet per minute rating of 1730. For the 7 inch fan the outer diameter is 8.5" and it is 2.5 " deep, that is , from front to back.

[bob123456789]

Here is another one from Amazon ( 7.5 " 440 CFM and $54):

www.amazon.com/Spal-30100393-Straight-Blade-Profile/dp/B003PB4444/ref=cm_cr_arp_d_product_top?ie=UTF8

[billg71]

Bob,

I really appreciate the help with some fan links.  It turns out I bought a Chinese made fan some time ago that is about 8" in dia.  The stock fan 5.5" housing dia.   I think I can wedge it between the hoses on the radiator to replace the stock fan for a test installation.  It doesn't matter if it's not centered exactly.  I don't know the CFM capacity but it's a bigger fan and draws more amps.

I'd have it done by now except I had to take care of an oil drain plug leak.  I bought a Smart-O plug made to solve the problem.  I didn't have my glasses on when I installed it and didn't notice it was half a mm undersized.  It stripped the threads in my case.  Yes, it was the right thread pitch.  I ended up having to glue the old plug in with JB Weld. 

I bought this pump for future oil extraction through the dipstick hole:
www.amazon.com/gp/product/B00P9W8NLW/ref=od_aui_detailpages00?ie=UTF8&psc=1

Here's a video on you tube testing it: 


Seems to work pretty good.  I have a manual pump buts its way too messy to use.

[bob123456789]

Good to hear from you.

In fans, bigger and drawing more amps should mean more CFM. Not having to buy a new one is great.

We are all watching to see if you are successful in getting improved cooling with this solution.

Tough going on the oil plug. It looks like you have a working solution. The important thing is to change the oil.

[billg71]

I finally got around to installing the big fan. It's this one I think.

www.amazon.com/Spal-30100393-Straight-Blade-Profile/dp/B003PB4444/ref=cm_cr_arp_d_product_top?ie=UTF8

It does cool better even though I had to wedge it in there a little cock eyed. A piece of aluminum from an aluminum flu section helped to close a gap on one side. I have not been able to make it go beyond the temp shown when it normally comes on but I've not had a really hot day to test it against yet.  It does bring temp down maybe 1.5 times faster than the stock fan.

Meanwhile it looks like I'm due for another head gasket. This'll be 2 in less than 7K miles.  According to the plug color, it is not running lean.  My oil is clean but I am getting oil in the coolant.  I also have intermittent bubbles through a brimming full open coolant cap.  That's a leaking head gasket I'm pretty sure, this side of a cracked head or cylinder block.   It looks like oil might get into the coolant through a failed water pump shaft seal but I doubt it.  Treatment with Fiber Lock didn't work forever, but it sure sealed pesky hose clamp leaks nicely.  It's also slowly losing coolant although I can't smell it in the exhaust.



Meanwhile I've heard the Chinese 250's have a flatter exhaust cam than the Helix to make US emission requirements the Helix didn't have to meet.  When I change the head gasket I'm going to a Helix cam for a bit better exhaust breathing, assuming that's true and it fits.  I'm wondering if that is why I can't keep a head gasket in this thing (Lance Duke 250). Maybe a milder exhaust cam causes over temp at WOT, all other things being equal. If anyone knows, I'd sure like to hear about it.

[bob123456789]

Bill

Thanks a lot fore the update on how well it worked. I've been wondering.

Cooling 1.5 times as quick looks like a big step in the right direction. The big question now is once you get back to the hottest time of the year whenever you were overheating (in traffic,...) does it make a difference?

The rest of us in a similar situation as yours will be wondering. Come July and August can you give us an update?

Does the charging system seem to be keeping up with the added load? If not you may want to add the headlight on/off switch so you can turn the headlight off during the day when it isn't needed and the extra juice is needed for cooling.

Is the fan you link to the one you had laying around or did you have buy it?

[jct842]

Nov 18, 2016 15:01:50 GMT -6 bob123456789 said:

Bill



Does the charging system seem to be keeping up with the added load? If not you may want to add the headlight on/off switch so you can turn the headlight off during the day when it isn't needed and the extra juice is needed for cooling.

stick a led in the headlight housing and it will appear the head light is on in case the cops in your state want to see a light.

[fwd60]

i have repaired at least six of the 244 cc engines everyone had the thermostat housing stopped up.remove the one bolt that holds it in and remove the housing and clean it out and clean
the end of the thermostat at the same time.there has been alot of corision in side of the housing and the water pump housing