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What is e.t.c. How does it work

42K views 15 replies 6 participants last post by  ebaysnyper 
#1 ·
1999 250 2-STROKE TRAIL BOSS

I have owned this Quad since new, always rock solid.
But i cannot get it to start at all. Have worked on every 2 stoke out there,bikes,boats, quads,weed eaters etc. Pretty simple stuff, got good gas,got
spark, got air, got compression, it should go! I will try to summarize the situation
quickly, labor day 2010 was the last time this bike ran perfectly. I let it sit in my
shed at the lake house until Nov. 6 2010 when i tried to start then, just cranks
no start. It's got spark, even changed the plug. Took it home, thought it had bad gas, cleaned out the carb and drained all the gas out. Recently i put fresh gas in ,no start, just cranks, no life no fire.
I have been through checking 3-4 times:
NEW PLUGS - 3
DISASSEMBLE CARB, clean all jets, passages, needle and seat, float level, choke circuit adj. throttle cable adj. vent tubes,everything multiple times
HAS SPARK, COMPRESSION, INTAKE BOOT GOOD, SUCKS AIR IN FROM INTAKE
The last idea is E.T.C. problem possibly? Any ideas please!
 
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#2 ·
Does it ever pop or hit at all? If not it may be electrical. You said it set in the shed at the lake for quite a while...have you checked the exhaust real good? Mice just love to build nests in them and they won't hit a lick if they can't breath. I had a fellow bring one to me couple years ago acting like yours and after I got the pipe off I found it stuffed full of acorns and dog food!
 
#3 ·
It baffles me!
Does not hit a lick at all, I have even sprayed carb cleaner in the intake port
while cranking, tried a spray of brake cleaner (shot a small fire ball out the back of the carb) ,dumped a little gas down the cylinder then tried to fire it up, nothing.
I did not check the exhaust pipe to see if was pushing air out the muffler.
But it is stock exhaust and the opening to the end of the pipe is small and 3 feet off the ground.
I would like to get some direction about this E.T.C. System. How does it cut
RPM to the engine in a stuck W.O.T. condition?

But any and all suggestions are welcome, I will check the exhaust. Thanks
 
#4 ·
Recently i have figured out how the etc works.If you lift the lid carefully off throttle housing you will see that the cable enters in and there is a 2 wire setup.The etc is like a failsafe if the throttle ever sticks open.The 2 contacts will touch and the unit will shut off.Cable adjustment and idle are critical for the etc to work.The Polaris manual gives a simple explanation as to how to adjust.
 
#5 ·
Thanks, I will look at the owner manual i have to set adj. E.T.C.

But I would like to know how it kills power to the engine, does it short voltage to the coil?

Remember I have spark in the cylinder, don't know if it is good or weak spark, but it sparks.
3 new plugs tried. Any body else have this situation? Thanks for any help.
 
#8 ·
This info is based on 1988 year model 2 stroke.
Compression service limit 115 PSI.
ETC Theory of Operation
When there is a problem with the throttle mechanism and the throttle lever is relased, the ETC switch contacts close. Power is delivered to the limiter module through the white wire, and engine RPM is limited to the "ETC limit." It is important to remember that ETC limiting will occur whenever two input signals are present at the limiter module:
1. The limiter module must receive voltage through the ETC switch circuit(White wire).
and...
2. Engine RPM must be at or above the "ETC limit". The RPM signal is delivered to the limiter module via the Yellow/Red alternator wire.
NOTE: The reverse RPM limit will override the ETC Limit when both are receiving voltage.
ETC adjustment: Adjust ETC switch until switch plunger is completely depressed. NO PLUNGER CLEARANCE 1/16"-1/8" throttle lever free play. (readjust idle)
I hope all of that info helps you.
 
#9 ·
One more thing I might add. Disconnect the black wire from the CDI unit. The limiter system will then be disabled. If the problem still occurs the limit system is not the cause.
Just to help me out. You said it fires. That means the spark plug is firing. You said it cranks that means the engine runs(starts). I think you mean the engine turns over but will not start. I will help you all I can. I don't know alot about 2 strokes. I have a service manual that covers 1996-98 Model Polaris.
Glad to help you,
 
#10 ·
Thanks tt425,
It sounds like your the guy to talk to with the Polaris knowledge.
I will pull the shrouds off and check the black wire diag.
And while i am in there will look around for any disconnected or chewed through wires
(rodent).
If you read back in this post about my situation, ran fine Labor Day 2010, sit in the shed
for 9 weeks hasn't started since. Has spark, has good gas in the float bowl, has compression
has air, no exhaust restriction, turns over no start
 
#11 ·
Thanks. I got all that info from a manual I have borrowed. How much compression do you have? Fuel is getting to the carb right? Look at the vacum lines going to the carb and the boots on the airbox for holes,cracks. The fuel goes to the by vacum created by the engine. Also Make sure the fuel lines are not breaking down on the inside. Ethanol fuel is not good for small engines and atv's. It creates alot of problems.
 
#13 ·
That info is based on 96-98 model 2 stroke engine.
After installing compression tester, open throttle and crank engine until maximum reading is obtained(approximately 3-5 revolutions)
Service limit 115 PSI.
Check and make sure that info is correct for your atv.
 
#14 ·
I think so, the 250 two stroke engines haven't changed through out the many years
they offered them.
Do you think that has to be it, not creating enough vaccum to pull ample amount of gas fumes
into the combustion chamber and not enough copmression to start the engine?
The top end is comming apart right now to see what we got. I will keep you posted.

By the way thanks for all your help and info.
 
#15 ·
YEP, the top ring on the piston was stuck into the ring groove.

I really never encountered a situation like this before. The piston was in really good shape,
( Just replaced two years ago) the cylinder looks good,needs a little clean up. The top of the piston was coated
with baked on 2 stroke and bad gas goo, which had the top ring glued stuck ??
One thing i have exprienced is PUMP gas sucks it. With the manditory up to 10% eythanol or alcohol or corn sqeesin's
is that in about 60 days even premium gas goes bad, starts to varnish inner carb parts and makes your bike run like sh@#t
Try to buy gas that happens to be sold at race gas suppliers.
 
#16 ·
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