efish

My Feedback: (5)

Hi, I have a CRRC Pro GF26 (the older machined crankcase version).

Anyhow, it was running fine and then the top end started giving problems. At WOT, it would run erractically as if fuel feed is intermittent (but there do not appear to be any bubbles in the fuel line) and just wouldn't rev up. Idle and mid range seem to be ok. Thought there was a problem with the carb/HS circuit, so I cleaned it out and reset the needles, but the problem's still there.

I would like to eliminate the EI as a source of the problem. On hand, I have a SPE26 EI that I know is working for sure. Can I just hooked it up to test using the CRRC Pro sensor? I understand that the curves may not be optimised, but at least I'll be able to take the EI out of the equation.

If the SPE EI is ok to swap in, the next question would be how do I tell the polarity of the sensor? Or does the sensor have any polarity? Both EI units/sensors appear to have polarity specific connectors. Or would it be better just to stick with the matching sensor. (Which I'll have to remove from the SPE engine)

Thanks.

540horses

have you tried changing the spark plug,a fouled plug will give those results. fouled sparkplugs do not always result in a nostart. they will idle but breakup when throttle is advanced.

efish

My Feedback: (5)

Hi 540horses, no, that didn't occur to me!

Thanks for the tip. I'm a newbie to gas, so I guess it did take me a while to get the engine in tune prior to which I guess it was running a little rich. Will give it a go and see what happens.

soarrich

My Feedback: (98)

You may have to change the sensor too when you try the new IE, they changed the order of the wires into the plug. You can use the old sensor by rearranging the wires, but it's easier to swap out the sensor IMHO.

A weak battery can give you those symptoms too.

tim220225

My Feedback: (4)

You also need to consider what the engine is timed at. I have a Falkon twin unit that is at 2 degrees BTDC IIRC so none of my other CH units would work without re-timing the engine. No big deal just need to remember that too.

efish

My Feedback: (5)

Thanks soarrich; a weak battery was the first thing that came to mind but as it turned out, the problem lay elasewhere. Guess chnaging the sensor isn't too difficult.

tim220225, thanks; guess I'll have to check it if I swap out the EI.

Funny thing was that the engine had been running fine; just suddenly wouldn't rev up normally.

Anyhow, will try a new plug first and hopefully all will be well.

rgoldy

You may also want to look at the distance between the magnet and the pickup. It should be as close as you can get it (.015 or so). If the gap is a little big at low speed the magnet still has time to do its thing-at higher speeds it just blows on by without tripping the sensor.
Could be your ignition is screwed too (sound like a auto mechanic...) but at least checking the distance thing is free.

efish

My Feedback: (5)

Well, I removed the spark plug and yes, it was oily and probably fouled. Put a new one in, but sadly, the problem remains.

Thanks for that Rich. Had a check and the gap seems ok.

Well, I'm about out of ideas. Pretty certain that the problem is with the EI since the engine appears to be mechanically sound and I've cleaned out the carb (twice). The engine was running fine before, but started showing problems within about 10 tanks. Guess I'll have to swap out the EI and see if things change.

efish

My Feedback: (5)

Well, just in case someone else has a similar issue sometime down the road, I'm posting to say that the problem is solved - sure enough, it was a faulty EI. Took me about 3mins to change out the sensor, wrap the SPE EI in foam and strap it in on top of the CRRC Pro EI; kicking myself for not trying this sooner cuz it took much longer to clean out the carb.

I'm sure other experiences may differ, but I've had rotten luck with these Chinese EIs - My first was a SPE 26 EI that worked flawlessly through testing and setup then died the day before its maiden flight (a blessing in disguise, I guess). This CRRC Pro EI died within 10 tanks on the ground.

But the replacement SPE26 EI has been pretty good; and it seems to work fine on the CRRC Pro engine. Haven't fiddled with the needles much, but even at 1.5 turns out on both needles and the factory timing with the old EI, idle seems fine and top end sounds good! Got my fingers crossed.... gonna break out the tach and start tuning next.

Thanks to all who offered help!

Mitsu1

My Feedback: (13)

The "Melody" brand EI unit that comes with most, if not all SPE engines is well known to be CRAP! Everyone with a SPE seems to have this thing crap out ... often before the maiden flight. My brother has a SPE 40 with the same problem. He bought a RC ExCell ignition and solved his prob as well.

captinjohn

Where can you buy this RC ExCell ignition? Thanks Capt,n

mistydee0

My Feedback: (103)

captinjohn,
Take your pick, Here are three that sell them.
ls pro engines
bcma engines
rc1 ignitions

mistydee0
LS PRO ENGINES

karolh

Don't forget that they are also available from CH under their CH label.

Karol

arobatx

I doubt highly that you will find a better price than buying an ignition from Ralph at RCignitions. I will not quote the price here...but check with him and I think you will be glad you did.

Ralph Cunningham
RC Ignition
1783 Whitehall
Williams, AZ 86046
928-635-2455


Chad