need help with my kfx400

Bigred93

New Member
Jan 2, 2014
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leaking coolant into oil. Not sure where. i have the clutch cover off and its in good shape. When i drained the coolant from the rad there wasnt much in it. there was alot of milky oil tho in the engine. idles and rides fine. Really need help with this.
 
There could possible be a head gasket leak between a water jacket and oil passage. Do not run the engine until this is figured out, coolant mixed in the oil is not good on bearing surfaces.
 
i have the water pump off and im going to replace the o rings and mechanical seal. how could i tell if its a gasket or cracked head tho? the oil was milky but the quad ran fine. idled fine to. no problems starting.
 
You have a bad gasket or seal, I'm not familiar with the kfx 400. The pump gasket may be shot?
 
It will run fine because it's not affecting compression.....yet. Coolant in the oil is a typical head gasket issue. You'll have to remove the head to examine. The leak will happen more when the engine warms up and coolant pressure raises.
 
if it was the head gasket wouldnt it be coming out the exhuast as white? i will deff check into that tho.
 
how hard is it to get the head off one of these? i assume aloooot harder then my blaster...
 
if it was the head gasket wouldnt it be coming out the exhuast as white? i will deff check into that tho.
If it was a leak between a water jacket and cylinder, then yes it would be noticeable by white smoke (steam) coming from the exhaust. There are passages supplying oil and coolant to the head. These passages are sometime close together and not much sealing them apart. A small leak can make this happen and will continue to get worse
 
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how hard is it to get the head off one of these? i assume aloooot harder then my blaster...
A KFX400 will be more difficult of coarse because of timing components. I replaced both head gaskets on a friends KFX 700 ( external leak). It's not that bad if you take your time and have a service manual near by for torque specs.
 
now when i emptied the rad it was near empty, that kinda hwy i thought it was the pump, it just made more sense that the coolant was flowing thru a crack in mechanical seal. but i see what ur saying now
 
now when i emptied the rad it was near empty, that kinda hwy i thought it was the pump, it just made more sense that the coolant was flowing thru a crack in mechanical seal. but i see what ur saying now

Of coarse change the water pump seal and see if that will fix the problem first. I have seen more head gasket issues when oil and coolant mix, but you might have a different issue. Report back after the seals are changed, hopefully that's all.
 
deff will. thank you. iv been on so many forums and this one is always the best. really, thanks!
 
 
did you order a new seal? I looked through the forum and those ideas are all over the place. 45 mins to change a head gasket? Maybe for a pro... Not very helpful it seems. Can you post a pic?
 
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there in the oppostie order....last pic is what it looked like at the start...then the first pic is what i have now...cant seem to get that metal peice out. and im not a weakling...channel locks and all
 
Do you have a pair of vise grip needle nose? It will offer a better grip then channel locks. Or try a medium size flat head screw driver to carefull pry up on the seal.
 
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yup tried that too...im just wondering tho it theres a step, before pulling it out...like if im supposed to get the bearings out first.