350x Issues (Saga III)

[ps2fixer]

Nice, was also going to mention last I knew Mike's cdi's had issues with the 85 style stator, unless he worked out a solution on that, my guess is the CDI needs a smaller capacitor inside, but I don't know the design well enough to know 100%.

The 400ex CDI I tested with did work on my machine for idle and med rpm, but high rpm it cut out like a rev limiter, ok if you drive the machine easily and never go above like 4000 rpm, I tend to run my stuff hard, so I want it to hit the high rpms lol.

No experience with Risk's, but I suspect there's a possibility that they would also have the issue with the 85 style stator.

From my old testing, the only good CDI was OEM.

Btw do you still have the bad CDI's? I have one bad 350x CDI that can't be turned off, would be interesting to get the ones off you and mess around with them some day. I doubt I'll be getting into the CDI reproduction side of things, but I have the experience for like 80% of the process. I've had custom circuit boards made, can solder connectors, have a 3d printer for a housing, I just haven't done the epoxy potting before. If I ever did anything like that, I'd defo want to have a solid way to measure ignition timing and energy transfer (aka how much energy goes into the CDI, and then outputs to the coil). Since it's all analog on these machines, I'm pretty sure everything is balanced out in design but would be nice to validate that's the case. I've done similar with the voltage readings before but that doesn't tell the whole story.

[ATC King]

Is there an obvious bad part in this? What fixed it?

[ps2fixer]

I could be wrong but pretty sure OP just put on a known good working CDI and it just works. I suspect that means the other ones he had issues with were bad or about to fail and had bad luck.

Guessing the replacement CDI is for the orig machine the OEM CDI came from.

Btw worth a mention, even though 85 and 86 style stators are different, the OEM CDI is the same for both.

[patriot1]

Since I fixed everything at once-I never isolated the issue.

Could have been 3 bad CDIs that worked but then didn't?

Engine wasn't grounded?

Chinese switch?

Runs good now though.

I have not tested the Chinese 400ex cdi on the donor bike but Rick's showed up today so hopefully donor will run off one or the other.

[ATC King]

At least you got it running.

That's a lil bit of a load off.

[Dirtcrasher]

Nice, was also going to mention last I knew Mike's cdi's had issues with the 85 style stator, unless he worked out a solution on that, my guess is the CDI needs a smaller capacitor inside, but I don't know the design well enough to know 100%.

The 400ex CDI I tested with did work on my machine for idle and med rpm, but high rpm it cut out like a rev limiter, ok if you drive the machine easily and never go above like 4000 rpm, I tend to run my stuff hard, so I want it to hit the high rpms lol.

No experience with Risk's, but I suspect there's a possibility that they would also have the issue with the 85 style stator.

From my old testing, the only good CDI was OEM.

Btw do you still have the bad CDI's? I have one bad 350x CDI that can't be turned off, would be interesting to get the ones off you and mess around with them some day. I doubt I'll be getting into the CDI reproduction side of things, but I have the experience for like 80% of the process. I've had custom circuit boards made, can solder connectors, have a 3d printer for a housing, I just haven't done the epoxy potting before. If I ever did anything like that, I'd defo want to have a solid way to measure ignition timing and energy transfer (aka how much energy goes into the CDI, and then outputs to the coil). Since it's all analog on these machines, I'm pretty sure everything is balanced out in design but would be nice to validate that's the case. I've done similar with the voltage readings before but that doesn't tell the whole story.

If anyone could, I know you could reproduce them, everything you make is sweet, and those parts are just mechanical connections. I wouldn't let the epoxy hold you back at all, that's the easiest part of it all. I'd probably pour the epoxy and then place it in a small vacuum chamber.

Nice to you you still kickin around!

[Dirtcrasher]

Just to clarify my statement on the fly wheels for future reference for anyone. If you have ever had to deal with the Goki starter kits you will discover that the 86 fly wheel is closer to the centerline of the engine than the 85. The starter gear for the Goki will either bind or miss the ring gear because of it if you have the wrong Goki kit. If the taper on the cranks are the same, than the taper on the fly wheel is in a different location . The stator has to match the fly wheal you are using. The 86 fly wheel will fit over an 85 stator but have a weak spark because there is too much of a gap. The 85 will not fit over an 86 stator. I believe you can swap fly wheel / stator combo between the two years, but they have to be a matched combo.

"The 86 flyweel will fit over the 85 stator" - That is EXACTLY what I did one time many years ago, I'm sure there's a post here about it. I had multiple new take out motors, and somehow I mixed up the parts. As you said, I had a real weak spark and it would try to fire, but never fire. I bet that has stumped quite a few people in the past. That issue haunted me for quite awhile. Everyone kept saying sheared flywheel key, but I had changed the flywheel because I lightened one. That was my clue.

I would guess it's the flywheel that chages that depth, I don't believe there's any differnce to the taper cut on the crankshaft.

And yes, it caused lots of GOKI issues for people too. IDK why Honda messed with the stator, but they are/were always striving to improve anything and everything 1mm at a time...

[patriot1]

Yes crasher: I actually read about your ordeal when I was investigating this!

PS2: You should be receiving the box of CDIs any day now-let me know when they arrive.

The Ricks CDI works great on the donor bike (as far as I can tell)

A little progress:



Waiting on a clutch cable before I can test ride it. I actually had a new motion pro cable for an 85 but this is an 86 engine so I ordered the proper one.

I'm not sure what direction I will go with the tank? Trying to get everything mechanical worked out first then I will figure the tank out.

[MrConcdid]

I'm glad you got it figured out, hopefully PS2fixer can shed some light on those CDIs
I'm am learning the 85 350x valve guides are different than the 86 and the 85 are discontinued.
I was able to source some compatible guides from www.jrtrikesports (greg jr)

MrC

[patriot1]

Well, I guess it took me over two weeks to get the clutch cable situation figured out but that's what I did today and I got to ride it.



"White Power", this is a bada$$ machine. Too much for me to be riding until I get some brakes on it; also it wouldn't idle today so I'll deal with that situation later too.

Can anyone tell me anything about that exhaust? I have only saw a picture of one other one-sounds awesome.

I know it's a long shot but does anyone have about 8 inches of left side mud flap they want to sell?

[ATC King]

That muffler looks similar to the old FMF Megamax and White Brothers from days past. They are likely rebranded somewhere along the line, as far as the can goes, with the oval disks. The mid pipe looks to be an actual reverse cone megaphone but without looking inside, it may just be a megaphone. Either way, it's probably one of the better performing pipes for a 4 stroke single.

It's certainly vintage, as in you can't buy them new anymore or even hardly find them used in good condition.

I had and FMF Megamax, in really good condition, sold it and later realized the machine I had it on ran the best with it. Several years later I found another one, in rough condition, but bought it anyway. I'm still working on putting that one back in action. Have it apart, some damage repaired, blasted and painted right now just waiting to set something up to cure the high temp paint, then put it back together.

They're loud though. Not much getting around that without choking them down. The FMF came with a quiet insert but that really defeats the purpose and may as well run stock with the baffle removed as they'll probably make the same power. The FMF is loud because it has a large diameter, short length baffle, really not much of a muffler and yours looks abut the same. More of a resonator than a muffler. Stealthy they're not.

The reverse cone megaphone is what helps the power, not the loudness, but one long enough to actually muffle noise would be heavier and unsightly.

If you haven't guessed by now, I say keep it as long as you have a 350X. If you change exhaust you'll probably end up going back to it unless quiet is your goal.

[patriot1]

Dang...You really are the King! Thanks for the information. Pretty cool.

[ATC King]

Thank You

Something that is missed by most now, because they don't even research recent history, is the majority of budget priced modern exhausts are just peddling marketing. They're a waste of money for power, a bump in compression makes more power for less money, if DIY It's all about the looks now, because most don't even sound good. That's even more true for modern single cylinder engines because they sound terrible with a loud exhaust. The high revving singles of today aren't exactly pleasant sounding. On a race track, with a race tuned engine, they sound as expected, but for normal riding...

I've spent a lot of time and money on exhausts as an average rider. It's the last thing I'd spend money and time on now. I have what I have and don't plan to be dropping coin an any more fancy aftermarket exhaust until I have an engine that needs it, then I'll only build my own or buy an actual performance exhaust that's the best match for my build.

One bike I put the original muffler back on is only because I'm working on a used exhaust to go on it. I've had many on this one bike and hardly anything is original or untouched about it now. It doesn't even have the same engine anymore. Not a replacement, an engine from a different model. I've had the bike over 20 years and it's been changing every since. It was nothing special to start with so I had no reservations about modifying it.

Here's a picture of the FMF Megamax (top) pipe without the silencer, and the same of a typical Supertrapp midpipe, that goes on a similar bike.



FMF is a reverse cone megaphone. It's made from at least a dozen parts, welded together. No way would anyone offer it now unless it was $$.

The Supertrapp midpipe is the typical 'performance' pipe most have anymore. That was what came on the bike it's on an this is the second time I've refurbished it. I'm not spending anything more for another pipe on that bike and I've had it about 15 years with the same pipe.

The FMF is replacing this.



The stainless head pipes are OEM Honda. The stainless muffler is a direct fit Supertrapp. The separate head pipes join the collector WAY on back.

All the pipes are very different and it's noticeable in how the engine responds to them. I've not just been swapping one humdrum Amazon special for another, I had to look for them, they're all vintage.

Pipes, real pipes, are seriously needed for performance. They really need custom built, but some off-the-shelf ones can work pretty good.

There's formulas, but they're always just guidelines, at the best. It takes trial and error to come up with a pipe that makes the most of the engine it's bolted too.

Here's a link with a lot of typical generic talk, but some good pictures of single cylinder, four cycle exhausts for racing.
https://www.thumpertalk.com/forums/t...-a-big-single/