Retard!

[keatonx]

That info you referenced is talking about a 2 stroke, that naturally requires timing retard at high rpm (and in this case, the CDI isn't giving it). Yours is a 4 stroke that likes timing advance at high rpm. There probably isn't anything too wrong with your stock timing (not to say that it can't be further refined, but styll)

 

[keatonx]

My guess is that if anything, you'd want to advance the timing

 

[HeadSmess]

complete concurrence... dont get the requirements of two and four strokes mixed up...and ignore most of that drivel dragged in by a certain cat. close examination reveals several flaws here and there...

fourstrokes...ive always found ignition on any engine to be pretty irrelevant. yes, you can go too far both ways...advancing will reduce power, and make things hot...retard will reduce power but the thing will always start... but usually the factory is pretty spot on, even after doing major surgery elsewhere...which is a definite must on a four stroke!

it does help to get it in the right spot but its usually fixed for a reason... these days of CDI, nobody has to remove and readjust points... the manufacturer has spent the money on research and development...

not saying what engine it is, i can only assume that its a standard industrial engine...meaning, more than likely, a single lobe cam operating both valves.shame. not much you can do to the profile to improve it. can experiment, but each change affects both valves, and the curves they follow are NOT symmetrical! ie...you need a lab for conclusive results. old briggs and stratton, and other similar engines have separate cams...which can be modified

cam design is complex and theres things like "j3rk" and "float" and g-forces and strength versus load versus wear/life type things to consider... not for the ametuer to go making new cams! some engines, the parts are out there... most arent!

ports... removing manifolds will usually expose nasty casting flash, brutal square and right angled airways, gaskets that arent cut properly, the works... the smoother, and curvier the ports are, the better airflow will be, the better performance will be.

you can use jbweld/epoxy in the intake port to make it pretty... bigger is not always better!

exhausts... theres an ideal length pipe for any rpm with a given set of cams.

carb... most industrial carbs are junk...


slots...yep, should be obvious enough... the ones that the bolts go through to attach the thing to the cylinder...assuming its a cylinder mounted coil... move in direction of crank rotation is retard, against rotation is advance

 

[KCvale]

Does a jaguar cdi work for 4 strokes?

NO! And it was incredibly ignorant to even be talking about 2-stroke CDI's in the 4-stroke forum to begin with.

If you have the HS 49cc 4-stroke get yourself an NGK 7544 (CR7HIX) Iridium spark plug, that alone will be something you imminently feel, pull of the stock box exhaust and throw a real tailpipe on, heck even a 2-stroke non-epa goes right on, and boost it some more.

Start with the cheap easy stuff to let it run and you'll see the timing is just dandy ;-}

 

[darwin]

OK I cannot let this go. Why is a spark from an Iridium plug more effective then from a platinum plug? Gotta hear this. Platinum gives more durability.

 

[El Sid]

thanks guys. Good info. In my research I have learned the lower the number on a plug the hotter. Now I need to look for iridium and platinum. I'll try them both, what the hell. I did get another pipe and broke the governor of the carb. lm looking at opening the case and taking the governor out there as well.

Check out my latest in my project. and please feel free to advise. Especially if something rubs you wrong.

Apollo creedo take 2: http://youtu.be/Xbf73934IYY

 

[El Sid]

One quick question, Valve gap, 0.003 for both intake and exhaust?

 

[Robot]

I don't know what you expect to gain on a $95.00 2 stroke but if that's what you are working with then you will get more accurate timing with pure silver brushes or coil portion of the ignition I'm not sure which it is but likely spark is advance via tin or copper once establish MMMMMK ?and plug wire on this engine or any working with a magneto type ignition the rpm range is limited for more than one basic reason.

 

[KCvale]

OK I cannot let this go. Why is a spark from an Iridium plug more effective then from a platinum plug? Gotta hear this. Platinum gives more durability.

http://densoiridium.com

---
Q. What makes Iridium better?
A. Until recently, platinum was considered the best material to use on the top of an electrode because of its durability. However, Iridium is 6 times harder, 8 times stronger, and has a melting point 1200 degrees higher than platinum. Put that into a harsh environment such as an engine piston chamber, and you have a spark plug that can resist wear much better than platinum. Additionally, the DENSO Iridium Power alloy is so durable; it allowed our engineers to produce the world?s smallest center electrode (.4mm) which reduces the voltage requirements, concentrating its sparking power. Also, its smaller size, combined with the tapered U-Groove ground electrode, allows more room for the flame kernel to develop and produce a more efficient combustion.
---

I use them in every 2-stroke build because I can actually feel the difference and there is no manual gapping, they come pre-gapped with a cardboard cylinder over the end you slide off when installing

Why?
The end is a touch longer than stock so a slight compression gain I assume, but it's a nice big spark I like as I also re-wire every Magneto to CDI build with excellent wire so every iota of the ignition can muster makes a nice big concentrated spark.

You don't have to 'let it go' Darwin, it's like $8 to feel for yourself.

 

[HeadSmess]

I don't know what you expect to gain on a $95.00 2 stroke but if that's what you are working with then you will get more accurate timing with pure silver brushes or coil portion of the ignition I'm not sure which it is but likely spark is advance via tin or copper once establish MMMMMK ?and plug wire on this engine or any working with a magneto type ignition the rpm range is limited for more than one basic reason.

do you ever talk sense, mmmmmmkay?


where exactly, are the silver brushes?

tin? wtf are you on? because ive its ever prescribed to me, im not taking it!

rhenium...why dont they use rhenium?

never tested it it out, but in theory, an engine will run on methanol with a platinum plug...without the spark.