Hello All,

My extech cooling head split in 2 pcs..

Where can I buy extech .21 cooling head?

Anybody using different head and what kind?

Thanks..

i think a main has the trinity phat heads, they were out befo the motors were but look just like the engine stock ones. Sure they would work??

SMracer, thanks for the help.

Pinoy, I know there were problems with some of the first gen Extech heads and they were replacing. You might contact Chad and see what they say about yours.

Dishsoap, what someone said earlier is correct. Put your idle gap b/w 0.5 to 1mm and leave it alone while you tune. If you get the gap too big or too small then you can't get the LSN right. Once you have the tune right then you can make small adjustments to the idle gap. Your problem really sounds like either an engine that's lost pinch (if it has a few gallons through it) or a small air leak that's making the tune wander.

Thanks cjtamu..

Do you have Chad's e-mail or contact #.


Thanks..

I know it still has pinch as I can feel it and plus it new and only has 8 tanks of fuel through it. I am guessing that its an air leak as well. I am starting to lose my patients with this engine.

You can PM him here, or go to the Epic website and see if you can contact him there. Don't know if their e-mail addys have changed with the move and merger.

Dishshoap, unless you didn't get something tight they normally don't leak when new. Mine was about 4 gallons old before the carb leaked and it's easy to fix with a little sealant. If you have a leak, there should be fuel somewhere (front bearing, carb boot, HSN assembly, etc.). Also possible that the air leak (if you have one) is in your fuel tank or in a line somewhere. I had fuel tubing tear at the top of the clunk in my 8ight tank and it caused off and on pressure problems. Last place I looked LOL.

Man I have checked and double checked everything. There is no fuel coming out from anywhere. Look below as to what I have done.

Update!!!!!

Here is what I did.

Front Diff. Bearings good gears good filled with new oil.

Center Diff. Bearings good gears good filled with new oil.

Rear Diff. Bearings good gears good filled with new oil.

I took apart the entire clutch. Shoes were good, springs were good, all bearings were good. The front engine bearing was good as well. I did notice some wear on the clutch bell.

Pulled the gas tank off and did a leak test under water. No leaks.

I put everthing back together cleaned every part and made sure everything was in working order.

As usual started right up and the idle was perfect. Put it on the ground good punch on the low and at high speed performed perfect. 4 minutes into it once the temps were at the appropriate tempatures it flammed out.

Pulled into the garage and put it on the box and it restarted no problem.
Leaned the low end 1 hour. After 5 or 6 minutes flammed out again. Pulled it in again and it restarted no problem. Leaned another hour on the lsn and had to stop.

I have nearly torn apart the entire buggy and everything seems to be working perfect. Power band was awesome and it ran flawlessly until it hits the 5 minute mark.

I am clueless now!!!!!!!!!
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When you re-fire it are you filling up the fuel tank prior? we had a similar issue this past weekend, what had happened was inside the fuel tank where the rock filter connects to the tank had a small leak. As we ran the car and the fuel level got right to the connection of the tank and rock filter it began sucking air and fuel. This wont show up if you pressure test the fuel tank under water. The easiest way to check if it is a fuel leak is look at the fuel line, make sure you have a portion of fuel tubing that is clear, and run the car until it dies, then look at the fuel line, there should be no air bubbles. Try re-firing the car and see if it continues to have air in the line, if you have air then you can narrow it down to a fuel delivery problem and not an engine problem.

I got your email Dish but figured I would post here. To me it sounds like you are too lean on top and too fat on the bottom with a slightly large idle gap. Be sure to adjust your idle on the linkage before you adjust your trim on the radio.
Also, check your carb boot. There has been some that have issues with leaks there. It really only takes a small hole. Chad can seal it up for you if you send it to him or tell you how. I put a small ziptie around the boot as well.

Make sure to seal up the carb neck. I had the exact same issue, I used some RTV and sealed the carb and boom, she will run all day now.

What smracer posted is what I'm talking about. It's a bear to find until it happens once, something I check regularly now. Dishsoap, if I were you I'd look at the fuel clunk. Then I'd set my idle gap properly and leave it alone. Put the engine back to factory settings, then get the top end where it's running pretty well. Then adjust the low. One other thing I haven't seen mentioned is to check your linkage. Be sure that the barrel is fully closed at idle and doesn't close up any more when you hit the brakes.

[QUOTE=cjtamu;5884249]You can PM him here, or go to the Epic website and see if you can contact him there. Don't know if their e-mail addys have changed with the move and merger.



Just send e-mail and pm. Hope he will answer back.

I will try OS or NR cooling head.

If extech is sirio base can I use the regular sirio green cooling head?

How much fuel do you think you have thru the motor to date?

anyone know where i can get a carb boot for my extec or know what other brand carb boot might work

8 or 9 tanks. The linkage is good on it. Based on today I think I have a serious problem. I took the time today to really focus on just getting it tunned with no luck. No matter which way I turned the needles the same thing would happen.

I tried every combination 1 hour at a time one at a time. It continues to make the same noise with the idle going high then going low and girgiling off throttle no matter what I do. In fact the more I got into it the worse it became.

Off throttle the only way I can explain the noise is like a high pitched girgiling noise that sounds like is blubering and its loud. Its not a normal noise and becomes worse when it hits operating temps. No matter what I did it didnt make better or worse but more worse. The noise sounds like a clunker of an engine.

At $360.00 I am pissed!!!!!!!!!!!!!!!!!!!! I havent done anything to cause this problem no serious crashes nor have over temped it.

I am stuck!!!!!!!!!!!