spooly
New member
Will your bike still run
ec 300 sudden power loss, wont rev
- Thread starter Fastboysparky
- Start date
Fastboysparky
New member
Yes. Bike starts 3rd kick from cold, 1st kick when warm, just lacks bottom end power and wont Rev into power band. I managed to finish an enduro but it was a pain having to short shift all the time.
Sent from my i phone whilst doing a tail whip.
spooly
New member
Me to I actually came 3rd in a hair and hound. Lol (technical track) mine suddenly went coming towards the end of a race. . I first thought exhaust then when I seen it was still there I thought fule.. if I hold my trottle open sometimes it give a kick like it wants to go, and I noticed that if I put it in gear and put some load on at very low revs there's a strange crackle off the exhaust or maby piston slap or something like that. .I also tried riding it with the pv held open with no avail. .
barossi73
Gold Level Site Supporter
my money is still on the ecu.electrical faults often show up under high load,eg when lugging in too high a gear, or high rpm,or when hot.besides I think you've ruled out almost everything else.another long shot,have you had a good look inside tank?could the fuel pickup be blocked and starving your fuel?old school problem with rusty metal tanks but its possible.also check your breather hose,if its blocked it will allow vacuum to build in tank,which will starve fuel supply.
Fastboysparky
New member
Fuel supply is good. Breather is clear.
Sent from my i phone whilst doing a tail whip.
Fastboysparky
New member
What spark plug was in the bike when it failed. Exact code if you can please, I have some new information.
Sent from my i phone whilst doing a tail whip.
Fastboysparky
New member
My new ECU arrived today and the instructions clearly state that a resistor spark plug and resistor plug cap must be used. After doing some research, I have found out that any engine using an ECU ignition should use resistors to stop ECU failure. Your BR8EG is a resistor plug but is your plug cap? I will be fitting the new ECU tomorrow and if my plug cap has a resistor, I will try the bike.
Sent from my i phone whilst doing a tail whip.
Sent from my i phone whilst doing a tail whip.
Fastboysparky
New member
The 'R' in BR8EG stands for resistor. I don't know how to check a plug cap so I'm just going to buy a new one.
Sent from my i phone whilst doing a tail whip.
Sent from my i phone whilst doing a tail whip.
wrench
Gold Level Site Supporter
I have been running standard plugs in my bikes for nearly 35 years.
Not a single ECU gone bad, or stator etc.
I am not telling you to go against what the mfg says, just saying.
I doubt that resistor/non resistor plug is your problem. Now, if the electrode is worn or the insulator is cracked, then I could see it.
But hey, I am human so I could be wrong.
Zman
Platinum Level Site Supporter
I agree with your comments. I personally have never purchased a resistor dirt bike plug. I have only killed one CDI and that one died trying to kill a run away WOT engine. I recall hearing that resistor plugs are often specified by mfrs to limit electro magnetic interference (EMI) and emissions.
Fastboysparky
New member
I have just fitted brand new ECU, warmed the engine and took it for a run. Absolutely no difference. Now I'm getting really p.....d off. Going to try the coil off my gas gas txt 250 tomorrow. I now have for sale a brand new ECU. Grrrrr
Sent from my i phone whilst doing a tail whip.
Sent from my i phone whilst doing a tail whip.
Fastboysparky
New member
I have never bothered about plug types before but when you get to the point of checking or replacing nearly everything on the engine, you start to try anything. And the new ECU has instructions with it printed in BOLD CAPITALS. Lol
Sent from my i phone whilst doing a tail whip.
spooly
New member
Sorry to hear that. .. have u taken out the power valve and cleand the carbon off it? I took off the side casing last night to make sure the pv activater was working correctly. Yes it was... im going to double check the pv again
barossi73
Gold Level Site Supporter
is it possible that the actuator plate is working correctly but not opening the valve?ie.broken shaft or such?sorry the ecu didn't solve it.has the ignition plate come loose or shifted?could the kill switch be faulty?is the pipe/muffler choked with carbon or split seam?eliminate muffler by running bike without(loud and a fire risk if its dry tho)does the bike just go flat or stutter/misfire?broken piston skirt?(unlikely but I had an old pe175 that broke a skirt and still ran(albeit very badly).same bike also developed a leak in float,which messed it right up and took some finding(twin floats,you could hear fuel sloshing in 1 float).breather hoses on carb restricted?stator winding?perhaps someone with some electrical know how could chime in with testing advice so you don't have to buy parts to test.did you check float level setting when carb was stripped?
Fastboysparky
New member
I removed the exhaust and watched the pv move. I checked the float. I had carb and exhaust off and inspected piston from both sides, not checked the ignition plate, not hot a puller. Expansion pipe is good, I can see clearly through the silencer. I reduced the float level slightly as it always spilled fuel on the slightest incline. Going to try coil and plug cap today.
Sent from my i phone whilst doing a tail whip.
