3XV De-Restriction Options Database

[Kneedown]

Gents

While I await the arrival of my little 3XV from across the country, I have been trolling the various forums and pages to see what cunning methods various owners are using to get the most out of their 3XV engines.

As far as I can tell there are plenty of options out there, but they also do seem to follow a very similar pattern. For example the impossible to find Sugo CDI seems a common requirement, as are new expansion chambers, there seems to be some copying of the SP porting, fiddling with power valves etc. etc

Just wondering if it would be a good idea to set up a database here so that we can all list the various options and results achieved, in one location, so that it can serve as a one step reference to 3Xv owners?

I was thinking of something along these lines...(which is not a complete list but just something I hashed up in a couple of mins)

Item                                Bike 1   
Model                              3XV1            
Exhaust               
Expansion Chambers                
Muffler                                              
Engine               
Cylinder Heads                 
Cylinder Barrell                 
Pistons                
Porting                
Power Valve                 
Reeds                 
Crank               
Ignition               
CDI               
Spark Plugs               
Fuel & Air               
Air Filter               
Carburettor               
Jetting               
Miscellaneous               
Speedometer               
Expected Power Output        45hp

I did up an excel sheet but was having trouble inserting it here. Happy to collate the data that is provided and figure out a way to link the excel sheet.

What do you guys think?? 

[entropy]

cool idea, but -- from what i've learned in this forum -- there isn't nearly enough data to fill in the last line of your spreadsheet. Just too many combinations of things. I mean its probably doable for bolt-on mods of something modern like an R6, just not the TZR. Of course there's plenty of info (in books and people) about what makes 2-strokes in general and TZs go fast... I'm definitely a non-expert, but I think the Bell book is pretty good for understanding why things are the way they are and how to change them.

RGVspares is supposed to get some sugo stuff soon

[entropy]

on 2nd thought, i bet yamaha either had or still has most of that data.

[twosheds]

45 nags is not so bad for such a small bike doncha know.

[EEKNOWS]

45HP is disgraceful. Bolt on bits rarely provide much in the way of improvements the real gains come from hard work and testing.
Sugo stuff might be great period bling but has been since superceeded by 3 and 4D ignition modules, not bolt on you have to do the work.
As with all road going versions of race bikes the main difference is the case volumes, race bikes will have the bigger volume.That be where the power is.

[entropy]

so you're saying that similar year TZ and TZR have different crankcase volumes? I had thought the 3XV and 3YL bottom ends were almost the same.

[ash33]

Have to agree 45HP is a little dissappointing.

However don't write off the Sugo gear, Yamaha factory techo's with unlimited research funds, parts and equipment developed a package that best suited the over all set up, which we still use as a base point.

Have to agree cases are where it's at, even if you just debur and match them (which Yamaha seemed to do fairly well compaired to other 2T's of the same era) it's a start.
The one thing that is confusing is why early TZ250 racers stuffed the cases with the reed block? I know it was intended to raise case compression, but at the same time it's reducing the case volume.

[EEKNOWS]

Almost isn't the same is it? If they had unlimited budgets you would think they would have done better than 45HP now wouldn't they. The Sugo stuff is WAY over priced and isn't 1% of the performance aftermarket ignitions available now for less than half the cost.Has a Sugo CDI got an in-built flatshifter and shift light?Other wise the Iwata guru's would have put that all in at the start.
It isn't confusng about case volumes at all,people copied off on another not really knowing what they were doing. Large case volume=top end small case volume= low end. You get either or the other but not both.

[Warwick]

It was the legislators not the engineers that gave the Jap market bikes the 45 Bhp limit. There's certainly plenty more potential within a 3XV motor.

3XV and 3YL/4DP TZ case volumes are pretty much identical AFAIK. SP cranks have meatier - TZ style - webs - thus taking up some volume, but porting and pipes is where you need to start your work if trying to improve an R/RS model 3XV.

[Collieman]

Although very happy with the 91 R that I have just bought, I don't think it will be too long before I am contacting Martin re pipes and porting. From what I have read on this site, that should liberate 60BHB with standard CDI. That should be fine for road and the odd track day 

Luke

[ash33]

Does anyone know of a full RC sugo kitted 3xv? I'd be very interested to know what peak output HP is. Or even a fully kitted 91'-95' TZ250?

At a guess I'd say it would have to be similar to other V twins like the RGV & NSR that make around 70 bhp factory kitted.

[EEKNOWS]

Depends on how you set the TZ up, but a top end set up will make 80 odd HP at peak, a mid range will be 70-75HP.
Ports and pipes can only go so far, the real tricks are control of ignition/pv is where the easy, cheap HP comes from. It isn't sexy or a bling but it works.

[entropy]

mine was fully kitted and has 3YL cylinders, but I have no idea on the HP.  it did pull really nice on the pipe, though. my brother didn't have it jetted right and seized it going ~100 mph in front of his house. a real bummer, but he didn't wreck.

I'm changing up the top end some and putting regular airboxes back on since its a street bike. maybe i'll dyno it after its jetted.

[mcyclenut]

Does anyone know of a full RC sugo kitted 3xv? I'd be very interested to know what peak output HP is. Or even a fully kitted 91'-95' TZ250?

At a guess I'd say it would have to be similar to other V twins like the RGV & NSR that make around 70 bhp factory kitted.

My RC Sugo kitted 93 SP makes 68 hp on a Dynojet 250.  I don't have the wire harness(I modded mine) or the carb-insulating mat foily thingy 

[ktzr]

Hello, what is "carb-insulating mat foily thingy" & what does it do & look like?