Can someone please help me?

[dxcody]

Ok so my gas was getting mixed with my oil, so i bought a new/used carb off a local guy, he asked what kinda exhaust i had, my quad is bone stock with the exception of a stage 1 hotcam. He said the carb had been jetted for a slip on. I threw it on without messing with the jetting, (my topend has about 15 hours on it.) My engine got so hot when i started it today. My buddy wanted to see and he took it around my 1/8 mile flat track and when he brought it back it was so hot you couldnt even hardly touch the gas tank. And it was smoking from the top end, not exhaust smoke either. I am supposed to go riding in like 8 hours and i was wondering if anyone knew anything about why this is doing this. None of the oil lines are clogged i can assure you. Is this from the jetting? i have JETS I CAN REPLACE THEM IF ANYONE KNOWS THE STOCK JETTING IF THAT IS WHAT YOU THINK THE ISSUE IS. thank you very very much.

[slightlybent47]

Boy you new guy’s sure keep the parts and shop guy’s busy! Lol

First off you should not be getting oil in your gas form the carb, so I don’t understand why you changed it.

Secondly you should never trust anyone’s word for something with out checking it out.

Next, if was getting hot just idling then why did you let someone ride it?

Why did you wait till you had a ride coming up to make the changes without knowing exactly what you were doing?

It sounds like you cooked the top end because it was too lean.
Sorry but the damage is probably already done.

Sorry but it sounds like an expensive lesson.

[dxcody]

the old carb was junk it bogged and flooded out everytime i rode, if it floods bad enough it can seep through and get down in your oil, i have been told that by many people. AND replacing the carb did stop that. and i let my buddy ride it because he is pretty mechanically inclined so i was hoping he could tell me if the valves were burnt or what. I only ride it for about a total of 10 minutes today, i dont think the top end it shot. can someone just tell me why they think it overheated. im not trying to be a d*ck i just need help, i dont want to hear about how i screwed up i just wanted to know if anyone had this problem before and if it could be a jetting issue. or maybe if i didnt get my timing right.

[slightlybent47]

Is the new one the same as the old one?
What jets were in the old carb?
Set the new carb to the old carb specs and that should get you real close to where it was.

Sorry but you can’t get by that easy on this forum. lol

[dxcody]

thanks, i am kinda in panic mode right now and now that you say that it seems like the most common sense way to do it but when im in panic mode my brain doesnt opereate normally. Well it never works quite right but you know what i mean. With this carb, it pops and cracks and backfires alot.
Normal jetting does that on this quad too because i have a hald dollar sized hole in the back of my muffler but this new carb does it way worse.

[dxcody]

ok so the only difference was, the A/F was 4 turns out and my old carb was 2 1/4 turns. do you think that could have been my problem?

[flyboy1294]

No I don't.

It sounds like you have a lot of issues all wrapped up into one mess.

1st, there is no such thing as a 'junk' carb. These things, especially on a 400ex, are so simply that any person with basic mechanical knowledge can totally rebuild one. You said it was bogging. Where on the RPM range did this happen? If you were idling then pinned it, or if you were in the high RPMs or what?

2nd, gas and oil mixing IS NOT in your carb! That is a separate issue entirely. Mostly internal. And I have never heard anything about flooding an engine mixing the gas.

3rd, the new carb needs to be rejetted also. SlightlyBent was right when he said you could've cooked the top end. Smoke coming from the head means oil has been exposed to a hot external surface at some point. This says to me that you either have a head gasket or a valve cover gasket leak.

4th, what was that about having a half dollar sized hole in your exhaust? Exhaust leaks are generally bad things. May want to pick up another stock one for cheap.

Letting your friend ride it was the wrong thing to do. When something is not right, running it isn't a good idea. And if you go ahead and ride it today, I can assure you that things will only get worse.

Now, here is what you need to do.
-Look up a carb diagram on this sight. Find out where your main and pilot jet are.
-Tear apart your carb and remove those jets.
-Tell us the symptoms your quad is having.
-Replace the jets with whatever is recommended and try it again.

Please understand that I am not trying to be excessively cruel, I am only warning you that you are getting ready to destroy your engine if you continue to run it like this.

[DnB_racing]

yes gas can blow by the rings and mix in the sump, or bad valves and a stuck float needle,and a bad vent ,

but either way its worse then just a carb issue, if you have really fixed the stuck float issue with a different carb, you probably still have more issues, even before the damage that riding with gas in the oil caused...

if you ran the gas oil mixture in the crank then you greatly sacrificed the lubrication properties of the oil and there's a good chance that's why its running so hot, and there is alot of damage including valves, piston, cylinder, bearings, basically everything that needs lubrication from CLEAN oil

[dxcody]

I changed my jetting last night, as you can see i didnt go riding today. last night before i even posted anything it was backfireing through the carb also. I just bought this quad about a month ago and its been nothing but problems since i bought it. Everytime i go riding something breaks. Like first i had to put the hotcam in. then it was the gas/oil thing which it did stop doing btw. and now its this i am about to just sell the dam thing for like 800 bucks.

[chronicsmoke]

I'll take it off your hands for 800$ ;)

[dxcody]

ok so say you guys were in my position, do you spend prolly $1000 on a rebuild or sell it and save up and buy one that works decent. Riding is my life. i love GNCC and if i am riding i am happy. What do you think i should do?

[CJM]

Gas going into the coulda been solved (if it was indeed a stuck float) by just rebuilding or cleaning the carb.

You probably will need a new topend since you cooked it by running to lean. Whenever gas mixes with the oil the oil basically doesnt lubricate as already stated. Dont go riding it, you may do more damage, crack it open and see wtf is going on in there

Ill give you 500 bucks :devil:

Id really recommend you take it to a qualified mechanic tbh.

[dxcody]

oh yea this time i am taking it to a shop but i just wasnt sure if it would even be worth it. or if i should just sell it, i just took it apart and the piston and rings and cylinder still look good, but the valves are more than likely shot. any one have any idea what a quote would be for a head/valve job and running it that hot i am sure it streched the hel! out of my timing chain.

[CJM]

Depends on shop rates, some can charge as much as 125 per hour.

[slightlybent47]

Well it would depend on what suspension mods have been done to it, if any.
If it just plane bone stock all the way around then it may only be worth parts, but if it is set up with good stuff then I would just do a rebuild on the motor.
If you don’t plan on doing suspension mods and want to just ride it as is: then a rebuild would be cheaper then a new/used quad.

Then ask yourself, will a stock 400ex do what you want it to do? Or will a better built bike be better for you? Are you at the point where you can handle a built bike?

Weight you options before you spend good money on it.

[dxcody]

well i talked to Donny Ockerman and he said his dad will hook me up with a top end rebuild and he will go through the entire motor and he has alot of parts that is just laying around his house, and he said it wouldnt be more than 5 or 600. That sounds like a good deal, and i can ride a 450 just fine, BUT i have rode 400's for so long i am 2x as fast on my 400 than a 450 and i am actually just as fast in the woods as my buddies on 450s. I can keep up just fine but when i turn 18 i am going to take out a loan and try to buy a 450r, hopefully one of Ockermans 450r's. They are beast. I am 17 now so hopefully i will be able to get this one rebuilt and it will last me until then. Thanks for the help everyone and sorry i didnt listen to some of ya from the get go.
(i have the mind to think i am a Professional mechainc sometimes)