3xv: Project Phoenix

[Steveog]

Thanks, guys.

Warwick - Yes. Returning from that track with the engine as one lump, is a testimony to new parts and Wossner pistons. There were more than one 4T that needed a ride back to the Paddock.

I didn't do a proper chop (but ran WOT for much of the day. It would seem the RH carb was on spec (#270 main). The LH carb by comparison appeared more lean, but had a bit of tan on the electrode. Maybe going to a 210 would be best for our summers. Pic of the LH plug included.

Dan - Thanks for the input on the Zeel. I was using the map as it came with the TPS turned off.

Yes. I can understand how the PV setting would be a good place to start in an attempt to re-gain the mid-range. Good suggestions. Thanks for following my set up.

I also believe returning the needles to their #3, stock position and going back to #15 pilots may help. I backed the air screws out 1/2 turn, but that made the 1/4 to 1/2 throttle response worse. I believe I was going the wrong way with the low-end settings.

Too many changes at once was probably my biggest problem on this track on this day. Time to start being more deliberate before going to the track, again. That may be mid to late September.

I'll try your PV suggestions first. Thanks for your input. I know this engine has potential yet to be unleashed. But, as strong as it is on the mains, it's simply harder to ride, fast...at least for me.

I also felt as if I had fuel starvation issues. On/off throttle at high rpm sometimes created noticeable hesitation. Plan on a modern fuel cap and adding a more TZ-like vent tube to the tank itself.

Also, going back through the LH carb is a priority I skipped over trying to get the bike ready for this adventure.

Finally, The throttle system must be changed to a dual-pull, TZ-Style. That would eliminate a big variable in the carburation.

Calling the 2T dyno guy in the morning. Just to see what his schedule might look like.

I have a lot to do before a dyno session. Including adding the slide adjustment screw to the RH carb.

Thanks for hanging with me, guys.

Steve

[Steveog]

Since my last post, attempting to find a dual-cable pull throttle for my 3xv has been frustrating. I understand frustration is part of 2T addiction, but...

Buying the new TZ pieces is absurdly expensive. Are there any opinions, besides those intended for Harleys?

I've tried to communicate with specialized vendors about this. No joy. Unless I'm willing to pay for a custom application.

I've asked this question before. Perhaps I'm just being lazy and hoping one of you guys has an answer to work with, while I work on other issues.

I'm wanting a quicker than stock "turn" throttle mechanism for a 7/8" bar, dual cable-pull (which I can source once I have the throttle).

Yes, I'm cheap, lazy and yet want something very specific. I may also be delusional.

Thanks in advance.

Steve

[ybk]

The TZ ones come by on yahoo from time time if you want to investigate that route..can also be expensive though (something like this ? : https://page.auctions.yahoo.co.jp/jp/auction/t550336035 )

Regarding that spark plug - it looks a little on the lean side?

[thump566]

In the UK, these guys spring to mind immediately. Appreciate you are in the US but may be worth a look albeit yet another custom cable you may end up considering?

https://www.venhill.co.uk/

Just a thought.

[41juergen]

Steve, onother suggestion from my side: as the bike is running now I would highly recommend to put in temp sensors into the pipes before going onto the dyno . That is the fastest and most reliable way to get the correct carb setting, also when having significant weather changes on track over the year. Maybe a Koso type of setup is affordable and (kind of) easy to build in...
Juergen

[Warwick]

You need a lesson on how to use Google, Steve... 

https://www.fondseca.com/index.php?main_page=product_info&products_id=1467&zenid=3186c316f64db8538151b04fdea624d5

http://www.meadspeed.com/products/yamaha/tz250/throttle

https://www.ebay.com/itm/Domino-Motorcycle-Twin-Pull-Throttle-Grips-For-Yamaha-TZ-Honda-NSR-Style-250cc/303147539287?hash=item4695005b57:g:S18AAOSwMEdc0vc2

Or perhaps the easiset for you:
https://www.treatland.tv/domino-dual-carburetor-throttle-assembly-1335-03-p/domino-dual-throttle-1335.03.htm

You'd then just need a universal throttle cable kit to make up the cables to suit - o get a pro outfit to make you up some? A local bicycle shop may even be able to make up you what you need? 

[Steveog]

Thanks to all.

Karl - Yes. I've found some TZ throttle pieces. Cost is usually my issue. That said, maybe this mod is just expensive and I need to suck it up.

Juergen - I've seen the EGT systems. It will be a bit before I get to the dyno. But, an EGT reference could only help. Appreciate the recommendation on an affordable solution. Our riding season can run through October (if we're lucky, even November). The temps and humidity can be comfortable to cool, as compared to right now. Jetting will obviously change.

Thump - Venhill seems to have only push/pull throttles. I just ran a quick scan. Could have missed it.

Warwick - Yes. Apparently I do need lessons...in many things. (HA). I've checked Fondesca and Donimo. They do offer some solutions, but as you pointed out, a bit of creativity is needed to build up a working system for a 3xv. Ebay in UK often returns results that yield "won't post to US". We both know this is a problem, specific to businesses, but does stop the incentive to find an answer, then need a bloke/broker. As I said, I just got Lazy. Yes. A bicycle shop would seem to be a good solution for custom cables. I do appreciate your help...deserved the sarcasm. HA.

I did purchase the Motion Pro throttle slide adjustment mod kit Martin suggested. I'm ready to get this throttle/carb sync issue behind me.

I knew this was a punk question. Glad you boys offered good solutions. I'll go hide in the shop now.

Steve

[Warwick]

Yeah, I suppose the issue really is that once you are into this level of bespoke tuning/modification, few solutions are available that are simple 'bolt-on' or off the peg. The last link for the Domino set-up is a US company, and the second to last came up on a US eBay search, so both of those should be good for postage to you. Personally I use a TZ throttle on mine, which works really well. I had some TZ cables too, but we couldn't get them to route as neatly as we wanted so Martin very kindly made up the cables to hook up the TZ carbs when the bike was over at his place from a build-your-own-cable kit - the soldering of the nipples being the crucial part here.

The TZ unit is pretty 'quick action' though, and will have an even shorter pull with the 28s of course.... Might even feel a little too short in use with the 28s as there's effectively 10mm less slide movement than with the TZ carbs? I don't know how the Domino compares in terms of action, but I'd imagine that it too is really designed with a 36 or 38mm carb in mind?

The feel/pull being a possible variable with the smaller carbs, might it be worth looking again at buying a universal DIY cable kit (Venhill kits are good) and simplifying your existing set-up instead, maybe? A new single cable from the stock throttle to lose the first 'splitter' but running direct to the actual splitter box instead, with two all new cables from there to the carbs?  That would probably be no more work than rigging up the dual pull throttle I reckon, and you still won't know how that set-up will actually feel with the little 28s until you are finished. And you'd save a chunk of cash too! 

If you don't feel comfortable tackling the cables, as I say, maybe have a chat to the local mountain bike workshop and see if they can help with making up the cables for you for that kind of set-up? That would be my own preferred course of action I think if I was running the 28s. Quite satisfying I reckon. And saving the price of the throttle would be a nice bonus too! 

[Steveog]

All good, Warwick. Details are very helpful.

I've seen some of the those single throttle cable-to-splitter systems on Motion Pro. Perhaps a phone call is in order, as they all appear to have only equal lengths following the splitter. As you discovered, cable lengths are crucial. I've got a text message into a good friend who's a bicycle nut who should be able to hook me up to his shop and tech(s).

Must be a luxury to have Martin as your "go to" man. He's helped and inspired me, long-range. If I had him available to tune my bike, "I'd be Bob's Uncle". Yes? (I have no idea what that means, BTW). I did find a great vintage bike guy with a modern machine shop, but while he's hip to 2t's, he's not a Guru.

I really want that dual cable "all the way" set up. I can live with a single cable splitter, if the cost gets out of hand. I got this.

Thanks.

Steve   

[Scotty4321]

Steve,
It's Bob's your uncle.
https://www.phrases.org.uk/meanings/bobs-your-uncle.html

I used pushbike cables for my power valve motor. They had screwed clamps to the inner but could have been soldered.
Not messed with throttle ones though. Would need to be heavier.

[Martin77]

Haha... I admire your attempts as weird british sayings Steve... 

Making cables is very satisfying, but can take a few attempts sometimes. Reminds me, I need to buy some better quality cable cutting snips.

Be careful not to use bicycle cables though, they're usually stainless steel (hard to solder) and much too stiff. I buy inner/outer cable meant for kart throttle cables, and often make my own nipples ( ). The smaller end nipples that go in the carbs are often soldered on even from yamaha, and thus cab be removed and used for your own cables. I often keep old broken cables just to take the nipples off. 

[Steveog]

Steve,
It's Bob's your uncle.
https://www.phrases.org.uk/meanings/bobs-your-uncle.html

I used pushbike cables for my power valve motor. They had screwed clamps to the inner but could have been soldered.
Not messed with throttle ones though. Would need to be heavier.

HA. Even the phrase dictionary doesn't explain why its used to mean "things are as they should be". I love the other derivations, too. Obviously, I'll just have to go with it. Fortunately, we all speak 2T. I'm using pre-mix with no TPS, Scotty. Thus the reason for wanting the lower carb to have its own cable. Thanks for your tip.

Haha... I admire your attempts as weird british sayings Steve... 

Making cables is very satisfying, but can take a few attempts sometimes. Reminds me, I need to buy some better quality cable cutting snips.

Be careful not to use bicycle cables though, they're usually stainless steel (hard to solder) and much too stiff. I buy inner/outer cable meant for kart throttle cables, and often make my own nipples ( ). The smaller end nipples that go in the carbs are often soldered on even from Yamaha, and thus cab be removed and used for your own cables. I often keep old broken cables just to take the nipples off. 

Yes. I get it, Martin. Thank You. I'm pretty good with soldering and have good quality cable cutting/crimping tools from my video production days. Digital coax, 110ohm is about the same diameter as motorcycle cables, so my current tools should work. I also have at least one nipple that was cut from the stock multi-cable. I can use that to test my effectiveness. Not sure if there's a Karting shop near me. The nearest kart tracks are at the same locations as the road course we use for track days.

"Robert's your auntie's husband", boys.

Steve

[Steveog]

Steve, onother suggestion from my side: as the bike is running now I would highly recommend to put in temp sensors into the pipes before going onto the dyno . That is the fastest and most reliable way to get the correct carb setting, also when having significant weather changes on track over the year. Maybe a Koso type of setup is affordable and (kind of) easy to build in...
Juergen

Thanks, Juergen. Been reading up on the EGT and wondering if the Koso system (which has a warning display) might not act as an insurance policy if a overheating were happening faster than I might see on the water temp gauge. Such as a cooling system hose/connection failure. An EGT system with "quick response" sensors isn't cheap, but one cylinder/piston failure would be far more expensive. 

Where on the pipe is it mounted? There seems to be disagreement here on the Forum. What say you? I'm guessing the sensor mount must be welded into my pipes.

Appreciate your getting me to think about this. I don't have great resources, but this seems as if an EGT is a very sound investment in reliability. Jetting advantages notwithstanding.

All responses welcomed.

Steve

[Steveog]

Spent some of my shop time yesterday adding a screw-type slide adjustment to the RH carb. A minor problem: the thread pitch on the only existing spot to mount the slide adjustment screw was slightly too, big. The kit I bought was intended for a Banshee and its carbs have a blank space for this kit to be mounted. So, last Friday, I filled the Vm28SS hole with JB epoxy. Yesterday I drilled and tapped the epoxy for the slide screw and lock nut.

I've included two pics and a video that should explain things.

I've since cleaned up the outer surface of the mounting hole (it came to me cracked a bit), but believe a rubber washer or o-ring is needed between the lock-nut and the carb body to avoid an air leak and make it less necessary to tighten the nut to the point it might strip the epoxy's threads. A spring between the head of the adjuster and the lock-nut might also add some reliability without putting stress on threads.

Comments and critiques appreciated, as always.

Steve

[Warwick]

Have you looked at if it would be feasible to replicate the stock set-up of a spring, washer and O ring on the inside rather than thinking about sealing it with the locknut on the outside? (check the other carb to see how it works). Personally, I would have used an oe upper carb adjuster for this mod as I have spares to hand, but I reckon you could broadly replicate the stock set-up from the upper carb fairly well with a bit of modification to the kit you have there? Having the adjuster 'spring loaded' for easy adjustment like the other carb has to be better than the slightly 'agricultural' lock nut set-up doesn't it?