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Post by rcq92130 on Jan 25, 2015 20:38:16 GMT -5
When I first got this scooter last year it had, of course, the OEM CDI. It worked ... but was boring.
Like everyone else, MoPower was not an option. Lots of stuff got upgraded.
CDI was a natural to upgrade - if nothing else, to get rid of the rev limit.
So I got one of the typical "red" (orange, really) :"advanced angle" CDIs. The thinking with these is to advance the point in the ignition cycle so that more power is captured. By igniting the spark plug just BEFORE TDC the engine transfers more of the explosive force to the piston, which in turn gives more torque.
~~~ BUT ~~~
Like many, as soon as all of this upgrade stuff was added 'starting' got really difficult. The engine would start to turn via the electric starter, then slam to a halt, then turn again (maybe repeating this several times) and finally catching. Once started it was fine - good even. Nice power. But the SLAMMING to an instant halt was worrisome. In fact, my first BBK 'melted down' (figuratively) after only 600 miles. Most likely this was because the in/exh sides of the piston were reversed, but i always wondered just how much damage that "slamming to a stop" caused.
The actual cause of the 'slamming" is the reverse preventer on the valve carrier - designed to prevent the engine from rotating backwards. With the ignition happening just BEFORE TDC there wasn't enough momentum in the flywheel (at starter rpms) to keep the engine turning forward. So the reverse preventer caught the cam and slammed the entire engine to a sudden halt. The starter motor then continued to turn, and after one or 2 of these cycles the engine would start and be OK.
~~~ FINALLY ~~~
So finally someone (maybe JerryS) explained what was going on and suggested the ADVANCING (not adcanCED) angle CDI. The notion with this thing is ignition is NOT advanced at low RPM (like when starting), but as RPM rises the ignition curve causes spark' earlier and earlier in the cycle.
So I got one from John (tvnacman, or something like it). Arrived last week.
FOLKS - THIS IS THE SINGLE BEST THING I'VE GOTTEN FOR THIS SCOOT. No more slamming to a stop at all; still good high RPM performance.
HIGHLY RECOMMEND!
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Post by alleyoop on Jan 25, 2015 20:45:21 GMT -5
Should of posted it as a question or problem you were having much earlier: Actually you have it backwards, advance timing means to fire much earlier on the compression stroke and NOT CLOSER to TDC. That is why the kickbacks occured it was FIXED advanced and firing early and not allowing the piston to get a good start off the block to get it past the compression stroke. Alleyoop itistheride.boards.net/thread/48/kickbacks-when-starting |
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Post by scooter on Jan 25, 2015 20:59:55 GMT -5
When I first got this scooter last year it had, of course, the OEM CDI. It worked ... but was boring. Like everyone else, MoPower was not an option. Lots of stuff got upgraded. CDI was a natural to upgrade - if nothing else, to get rid of the rev limit. So I got one of the typical "red" (orange, really) :"advanced angle" CDIs. The thinking with these is to advance the point in the ignition cycle so that more power is captured. By igniting the spark plug just BEFORE TDC the engine transfers more of the explosive force to the piston, which in turn gives more torque. ~~~ BUT ~~~ Like many, as soon as all of this upgrade stuff was added 'starting' got really difficult. The engine would start to turn via the electric starter, then slam to a halt, then turn again (maybe repeating this several times) and finally catching. Once started it was fine - good even. Nice power. But the SLAMMING to an instant halt was worrisome. In fact, my first BBK 'melted down' (figuratively) after only 600 miles. Most likely this was because the in/exh sides of the piston were reversed, but i always wondered just how much damage that "slamming to a stop" caused. The actual cause of the 'slamming" is the reverse preventer on the valve carrier - designed to prevent the engine from rotating backwards. With the ignition happening just BEFORE TDC there wasn't enough momentum in the flywheel (at starter rpms) to keep the engine turning forward. So the reverse preventer caught the cam and slammed the entire engine to a sudden halt. The starter motor then continued to turn, and after one or 2 of these cycles the engine would start and be OK. ~~~ FINALLY ~~~ So finally someone (maybe JerryS) explained what was going on and suggested the ADVANCING (not adcanCED) angle CDI. The notion with this thing is ignition is NOT advanced at low RPM (like when starting), but as RPM rises the ignition curve causes spark' earlier and earlier in the cycle. So I got one from John (tvnacman, or something like it). Arrived last week. FOLKS - THIS IS THE SINGLE BEST THING I'VE GOTTEN FOR THIS SCOOT. No more slamming to a stop at all; still good high RPM performance. HIGHLY RECOMMEND! Good deal, RCQ! I put one on "Scootie". I don't know if it helped, because I was fixing it up at the time, but it didn't hurt and I got 60 on the speedo with no major mods. Plus it was the same price as a regular one. |
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Post by JoeyBee on Jan 25, 2015 21:59:56 GMT -5
rcq92130 Thank you for the recommendation and great explaination. Ignition moding was next on my list since my carburetor and CVT are in tune. tvnacman I hope you have these in stock. I'm ordering one tonight.
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Post by rcq92130 on Jan 25, 2015 22:18:27 GMT -5
Good decision, Joey!
I might be wrong, but the "slamming to a stop" of the engine during starting was pretty damned worrisome to me. Thought at any moment the whole thing might just snap. And, maybe the violent halt contributed to the early demise of my 60mm BBK ..... dunno.
Anyway - tvnavman isn't yet paying me, so I have NO RESPONSIBILITY in case you are disappointed! But I'm pretty damned sure you will be thrilled! I was --- and seriously --- if I had to choose between a sensible variator and this CDI I'd go first with the later.
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Post by JoeyBee on Jan 25, 2015 22:32:04 GMT -5
Good decision, Joey! I might be wrong, but the "slamming to a stop" of the engine during starting was pretty damned worrisome to me. Thought at any moment the whole thing might just snap. And, maybe the violent halt contributed to the early demise of my 60mm BBK ..... dunno. Anyway - tvnavman isn't yet paying me, so I have NO RESPONSIBILITY in case you are disappointed! But I'm pretty damned sure you will be thrilled! I was --- and seriously --- if I had to choose between a sensible variator and this CDI I'd go first with the later. No worries, I'm not expecting significant gains. A BBK is far down the road since my scooter is only a couple months old. I have been planning on switching out the cheap stock ignition parts for better quality parts. But quality is more of a consideration over claims of being "performance" or "extra hot". |
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Post by rcq92130 on Jan 25, 2015 22:46:15 GMT -5
Welllllllll
My scoot had only 600 miles (3 months) when it saw a BBK!
RE: CDI
I just urge you to AVOID "performance CDIs" that are "advanced, not advancing, angle". I'm thinking the advanced (normally what is meant by "performance" are pretty darned destructive to the engine because of the starter issue.
IN FACT ---- I have a slightly used "advanced angle" CDI you can have for the cost of postage! No responsibility, though!
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Post by JoeyBee on Jan 25, 2015 22:55:59 GMT -5
Why so early on the BBK? We're you having engine problems that soon? My commute to work is about 4 miles with the highest speed limit of 45. So my 150cc has power to spare.
As for CDIs, hard starting with advanced timing CDIs was the reason I have been avoiding them. Plus the tests I have seen with them showed no noticeable gains, only causing starting problems. However, advancing the timing only in higher RPMs sounds like a solid concept.
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Post by rcq92130 on Jan 25, 2015 23:16:11 GMT -5
Why? Oh, I just wasn't satisfied with the stock 150cc power. And I like to mess with engines. And I'm stupid.
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Post by geh3333 on Jan 26, 2015 6:15:27 GMT -5
The problem I have with mine only occurs when my battery is low "which has again been often ". When I'm hooked up to a 10a charger or being jump from a car it turns over and starts with no problem , however one of the cdi's u mention will probably cut it out all together.
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Post by JoeyBee on Jan 26, 2015 7:16:19 GMT -5
The problem I have with mine only occurs when my battery is low "which has again been often ". When I'm hooked up to a 10a charger or being jump from a car it turns over and starts with no problem , however one of the cdi's u mention will probably cut it out all together. I ordered the advancing one from John last night. I'll update the tread with results when I get it. |
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Post by xyshannen on Jan 26, 2015 10:47:51 GMT -5
The problem I have with mine only occurs when my battery is low "which has again been often ". When I'm hooked up to a 10a charger or being jump from a car it turns over and starts with no problem , however one of the cdi's u mention will probably cut it out all together. I ordered the advancing one from John last night. I'll update the tread with results when I get it. I got my CDI from John and love it. With all I've done to my scoot it is very temperamental about the cold and doesn't like to start or run right when it's below 60 outside. With a stock CDI it seems like it's next to impossible to get it started without constantly having to restart it until it warms up. With Johns CDI it starts much easier and performance is great through the whole power band and I turn my scoot all the way up to 8k RPM all the time. I went through 2 DOA advanced CDI's before I found John. In fact in all my looking I never found any other vendor who sells a variable timing CDI. I wish I had found John before all that wasted time and money. John's price is very reasonable and I can attest that he not only pre-tests them but also stands by his product. My point to this post is that with the price and the person you are dealing with, there really isn't any reason not to buy this CDI or to go to any one else. |
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Post by ricardoguitars on Jan 26, 2015 12:25:42 GMT -5
I was experiencing hard starts as well after replacing the stock CDI with the "blue one", I had the habit of opening the throttle a bit when turning on the scoot, after having troubles starting it, I turned it on without touching the throttle, now it starts with just a quick touch of the start button always, even after a couple of days sitting on the garage.  |
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Post by tvnacman on Jan 26, 2015 18:35:42 GMT -5
Joey are you in TX ? If so your cdi went out today .
We are getting hit with a storm I suspect the post office is delayed .
Thanks for the kind words and support guys.
John
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Post by alleyoop on Jan 26, 2015 19:26:54 GMT -5
For those of you who have never used and or seen a timing light and never have seen the timing change on a car or a scoot here is JOHNS(TVNACMAN) demo of the ADVANCING CDI.
Alleyoop
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..BAD TO THE BONE..
