Motor loses power

[Sick0]

Its seams like my motor loses power after about 25 mins of uses. like if I'm doing laps. I don't think my carb is jeted right. It runs real strong then it seems loike it gets hot and lose a good amount of power.

[Chef]

It sounds like its just gettin hot. Buy one of those FST Oil Coolers, or a Pingry tank or somethin...The cooler is only like 117.

[Sick0]

So you only think its a only getting hot. Do you think it has something to do with jetting, I just worryed. I geuss. I built this motor my self, so I'm worryed I messed some thing up. I was thinking it was just the motor getting to hot. It didn't have this problem before put its fianlly warmer out side so maybe your.

[400grl]

Yeah - sounds like it's hot - mine does that too. Then, if you sit for a minute and then go again - it's like you have turbo for the first lap or two! :) Sounds like you need the same thing I need - a bigger oil cooler!

[UglyMotha™]

it could be jetting if your running your motor too lean it will run hot, and heat causes a loss of hp i would make sure your jetting is right on first and go from there


also you said you built the motor yourself, what did you do to it and what octane are you running if you run 110 or somwhere around you your motor will run cooler

[Sick0]

Well I just put a new carb on and trying to dial it in. I have a 10.8 pistons. I didn't think I need to run race gas,

[EX 80]

i use race gas in mine , good stuff :blah

[toby400ex]

Possibly clutch?:confused:

[Chef]

Originally posted by toby400ex
Possibly clutch?:confused:

No. A clutch wont cause a motor to get hot. But it could be getting hot enough to make the clutch slip, if thats what you mean.

[chad502ex]

Originally posted by Chef
It sounds like its just gettin hot. Buy one of those FST Oil Coolers, or a Pingry tank or somethin...The cooler is only like 117.

Hey Chef,

Just to let ya know, I've found the maker of the external oil cooler. It's a Perma-Cool Universal ATV Oil Cooler Kit (really power steering pump cooler pn#1008) for $35. Jegs Performance also sells this same kit for ~40. Just thought I'd let ya know what I found. It'll help people save $$$.

Chad502ex.com

[Sick0]

Clutch? It could ve that. because it seams like thats could be it. I'm on the stock clutch. But wouldn't the clutch let the motor rev when it slips. It seams the motor will lose power when I'm putting a lot of demand on tyhe motor. Like going up hill orcoming out of a corner real hard.

I think my clutch may be sliping but I don't think its reason for losing power.

I will try to get the carb better dail in and run some race gas see if that helps. I also have plans for aftermarket oil tank.

Thanks for the help.

[toby400ex]

Originally posted by Chef
No. A clutch wont cause a motor to get hot. But it could be getting hot enough to make the clutch slip, if thats what you mean.
Welll yeah, im not stupid.:ermm:

[Jay300ex]

To check to see if your jetting is proper, put a new plug in, go out riding for a while, then take the plug out ( when its cooled down of coarse! ) and observe the color on the ceramic electrode cover thing on the end. Fluffy black = too rich, white or gray = too lean. Wet black = to much oil being burnt ( probably not you ) what you should see is a tan color. This will probably be debated by people thinking of additives in gas, but its how they check them at the races to see how the bikes are running ;)

Jay

[NTPRacing#19]

To check to see if your jetting is proper, put a new plug in, go out riding for a while, then take the plug out ( when its cooled down of coarse! ) and observe the color on the ceramic electrode cover thing on the end. Fluffy black = too rich, white or gray = too lean. Wet black = to much oil being burnt ( probably not you ) what you should see is a tan color. This will probably be debated by people thinking of additives in gas, but its how they check them at the races to see how the bikes are running

uh there is only one proper way to do that test. when you cut the motor it must be revved out you can just putt in a let it idle and turn it off. you should get into like 3rd gear pinned and cut the motor and dont let off the throttle when you shut it off when the motor is dead and your just cruisin you can let go of the throttle. thats the right way to get a right reading in that test

[Jay300ex]

Originally posted by NTPRacing#19
uh there is only one proper way to do that test. when you cut the motor it must be revved out you can just putt in a let it idle and turn it off. you should get into like 3rd gear pinned and cut the motor and dont let off the throttle when you shut it off when the motor is dead and your just cruisin you can let go of the throttle. thats the right way to get a right reading in that test

Ok that sort of doesnt make sence... Cut the motor when you have the gas open? I tend not to do that back fires startle me.. I don't see where it makes a difference.


Jay

The difference it makes it that if you dont shut it down with the throttle in the full position you put the carb into a different circuit (needle not main jet) and not get an accurate reading.

IF you did your own engine work and the jetting proves other than lean you may have the wrong ring end gaps and that can cause the engine to loose power or worse.

That oil/ power steering pump info was great, and thanks. I am looking at getting one with more area for the oil to travel and thus allowing more time for the oil in the cooler.

[NTPRacing#19]

well you let go of the throttle completely when you hit the killswitch.

Originally posted by chad502ex
Hey Chef,

Just to let ya know, I've found the maker of the external oil cooler. It's a Perma-Cool Universal ATV Oil Cooler Kit (really power steering pump cooler pn#1008) for $35. Jegs Performance also sells this same kit for ~40. Just thought I'd let ya know what I found. It'll help people save $$$.

Chad502ex.com

does that replace the stock little oil cooler or is that like the one that is an add on to stock so u have 2:confused: Thanks:cool:

[chad502ex]

Originally posted by QuadMX18
does that replace the stock little oil cooler or is that like the one that is an add on to stock so u have 2:confused: Thanks:cool:

This cooler is an addition to the tiny litt'l stock cooler

Chad502ex.com

Here is a pic of the front of the 502. you can see the external cooler behind the metal grill.

Originally posted by chad502ex
This cooler is an addition to the tiny litt'l stock cooler

Chad502ex.com

Here is a pic of the front of the 502. you can see the external cooler behind the metal grill.

ok thanks;)

[Sick0]

Well I raced my 400 to day. the problem gotton alot worst.

[400ex99]

order some air scoops from tinner, they help alot... i use them on my 416; go up one on the main jet

[lilpoppy]

Hey Chad502ex that picture of that aftermarket oil cooler that you posted is that the exact one you put on yours? If not which one did you use? Did it make a big difference and are you useing in with a bigger oil reservoir? I was drag racing myne this weekned and it was getting fairly hot and I'm woundering if this is going to help.

[Sick0]

Airs scoops don't really help to cool a motor down. there more for looks.

[chad502ex]

Originally posted by lilpoppy
Hey Chad502ex that picture of that aftermarket oil cooler that you posted is that the exact one you put on yours? If not which one did you use? Did it make a big difference and are you useing in with a bigger oil reservoir? I was drag racing myne this weekned and it was getting fairly hot and I'm woundering if this is going to help.

lilpoppy

Yes the picture I posted is the exact external oil cooler I use and run. It helped cool my BIG BORE 502 alot. I'd guess the cooler helped reduce oil temperature of 40 degrees. The oil temperature used to be ~240-260 degrees, now its running 180-220 degrees, and as you know heat is the enemy (robs power and causes warpage). This cooler basically adds another quart of oil, and you can probally add another back to back if ya want to. Perma-Cool sells the same cooler as FST but for half the cost. The oil cooler is designed as a power steering pump cooler, but fits perfect on the 400ex. If you decide to buy this cooler from Perma-Cool, you'll have to make a grill like I did in the picture above to protect the cooler from punctures. The cooler can also be bought from Jegs Hi-Performance or from Perma-Cool for about ~$35. One more thing, I did not use the rubber oil lines they supply with the cooler kit, I went to a hi-performance auto shop and bought some braided oil lines the same diameter size to prevent the exhaust heat from bursting the supplied rubber lines (which I didn't use). Hope this helps. I'll shot digital pix if more detail is needed.

Chad502ex.com

[chad502ex]

Originally posted by lilpoppy
Hey Chad502ex that picture of that aftermarket oil cooler that you posted is that the exact one you put on yours? If not which one did you use? Did it make a big difference and are you useing in with a bigger oil reservoir? I was drag racing myne this weekned and it was getting fairly hot and I'm woundering if this is going to help.

lilpoppy,

I found a pix in my digital archive that might help visualize the oil line motor connection a little better. As you can see, the header was not installed either in this snap.

Chad502ex.com

[Jay300ex]

Originally posted by 440EX4me
The difference it makes it that if you dont shut it down with the throttle in the full position you put the carb into a different circuit (needle not main jet) and not get an accurate reading.

IF you did your own engine work and the jetting proves other than lean you may have the wrong ring end gaps and that can cause the engine to loose power or worse.

That oil/ power steering pump info was great, and thanks. I am looking at getting one with more area for the oil to travel and thus allowing more time for the oil in the cooler.

Ok I get yer lingo now. But I just can't seem to imagine that it would make a huge difference in the insulator color if you rode, then stopped, shut if off, then checked it when it cooled down. A split second of pilot will really throw off the readings that much?

Jay

Originally posted by Jay300ex
Ok I get yer lingo now. But I just can't seem to imagine that it would make a huge difference in the insulator color if you rode, then stopped, shut if off, then checked it when it cooled down. A split second of pilot will really throw off the readings that much?

Jay


Jay,
I used to think just that till I was shown how different it can be.

How this was explained to me years ago is that there is some pretty violent explosions happening inside the engine and a small change in rpm, fuel delivery or even temp can make some pretty big differences in those explosions.

So backing off the throttle or letting the engine continue to run on a different carb circuit will make a change in the combustion conditions and the plug.

[YZROOSTINYA]

CLUTCH SLIPPAGE will cause a tremendous amount of heat!!!!

what happens when the plates slip? they rub each other at high rates of speed!

what happens when things rub each other= FRICTION!!1

what is FRICTION? HEAT!!!

if your clutch is slipping you are not only building up heat but killing your oil!

[max400EX]

Change your oil after you ride or something and see if there is some glitter in it, if so, the glitter = fragments of... yes, you guessed it....... clutch plates!!!(and if not clutch plates... i am soo sorry)