Major Failure Where to Start

[Steveog]

Crank. I hear you loud and clear. So far, I’ve only sourced OEM parts or superior items, such as Timken tapered roller bearings for the 3xv steering head.

Appreciate the warning. Sorry for your issues. We all learn a bit more about these amazing bikes as we go forward.

I intend to go forward.

Steve

[James P]

Going to pre-mix seems more complicated in some ways. Believe I've read here that mixed fuel can't just sit in the bike and doesn't store well in general. There's also the off-throttle issues (coasting) that might cause oil starvation. I find myself either all on or off many times on some tracks.

Steve; I think the problems with pre-mixed fuel and oil only apply if you use certain oils (e.g. castor) and perhaps also certain fuels. Many/most two-stroke oils are self-mixing when added to fuel - I think that kerosene/paraffin is added to the oil by the manufacturer to achieve this. There are some non-castor synthetic racing oils which are not self-mixing, so must be 'shaken' before use. If you are concerned, mix some fuel and oil in a glass jar and see how long it takes for the two to separate. I tried this with the oil I use and left the jar sitting on a shelf for more than a year with no sign of separation.

As for oil starvation; I am open to the possibility that sustained high engine speed on closed throttle may cause some problems. However, no TZ250s have oil pumps fitted as standard (do they...?  ). I know Yamaha used/experimented with oil pumps on race bikes in the 1960s and early 1970s, but seemingly gave up. Did any Yamaha production race bike of the 1980s or later have an oil pump? I don't think so, but there are many things I don't know .
I take the view that using pre-mixed fuel and oil gives peace of mind - if the engine is running, you know it is getting oil. Although uncommon, oil pump systems have been known to fail (whether by drive gear breakage, advanced wear, line or pump blockage, serious leakage, lines falling off etc.) and you'll probably never know until it is too late!
Although some may disagree, I think the peace-of-mind factor is well worth the extra time it takes to measure the oil when filling up. I also like the reduced complexity brought about by removing the oil tank, pump and lines.

Regards,
James

[Steveog]

James. Thank you. I considered pre-mix before this most recent system failure. I was advised by several I trust here on the forum and a local 2T tuner to leave the pump and tank in place. You've given good reasons to consider pre-mix. I've been using Bel-Ray Si-7 (specified for injection pumps), but actually purchased a liter of their oil engineered for pre-mix. So, pre-mix is part of my thinking, but not a done deal. The pump on my 3xv1 is purely mechanical and you can see, the pics of my cylinders only show the wear and tear of a 27 year old 2T that came with 19K on the clock. I added a couple of hundred hard km's this summer.

I'm guessing you've read my plans. This is a track bike, only. I have access to leaded 110 octane, pure race gas, which should add some additional lubrication, if I decided to go pre-mix. Thanks for your opinion James P.

Now, here's a new question: Because I'll have the motor completely apart, I'm tempted to have the engine internals "micro-blued". This process is used to reduce internal friction of moving parts. http://www.microblueracing.com/ This company is centered in North Carolina, US. Guessing it sprang from NASCAR, where the cars are so closely matched, every possible advantage might help. Plus, my local Yamaha dealer/engineeer recommends it for all the 4T race engines he builds.

I'm curious if anyone has used this process on their 2T's? Particularly, the piston and cylinders. The bike shifts up and down flawlessly with only a minor "clunck" kicking it into first. Is this process worthy of consideration or a waste of money better spent elsewhere?

[SeaR1ck]

If your goal is to make your wallet lighter otherwise waste of cash. Money better spent on suspension upgrades and brakes.

[TZRtim]

If you wanted the best 1 change upgrade for your money ( quite allot ) carbon wheels . Paint them if you still want std looks ? 

[Steveog]

Rick. I assume your comment is about "Micro-Blue". I'm not sure what it costs, but it was just an idea my local dealer keeps pitching. I have no "extra money". I figure my rebuild will total about $3K USD. Your opinion is valued and is so noted.

I have modified the suspension with good success. I rebuilt and stiffened the forks and shock was re-sprung, but obviously it needs replacing.

TZRtim - Ha. What about carbon brakes, bodywork, tank? Maybe I could get Pedrosa to ride it. He's available and a 70 pound weight reduction. I do get your point. Thanks for the laugh, too.

Steve


 

[chubba]

manuel fenati is free at the minute it you cant get Danni

[Crank]

manuel fenati is free at the minute it you cant get Danni

Apparently he's a demon on the brakes!

[teezer250]

manuel fenati is free at the minute it you cant get Danni

Also ROMANO Fenati is free.

[SeaR1ck]

Steve he wasn't talking about carbon brake discs. He meant carbon fiber wheels as in lighter weight faster spin up has a positive effect on suspension the whole unsprung weight thing.

But these jokesters are derailing the post with brake jokes. 

[yorkee]

I have modified the suspension with good success. I rebuilt and stiffened the forks and shock was re-sprung, but obviously it needs replacing.

mind to share how you stiffen the fork? 
I tried to work on the R fork, there are no stiffer spring available.  The only thing I cando is to put spacer to aid the preload, which is the same as the preload adjustment.

As for the valving, I can only adjusted by changing the fluid weight, which doesn't have the luxury as the RS/SP/SPR/TZ forks where they can have some adjustment on the fly.  I was told I can drill/cover the valve hole to achieve some level of adjustment, but the fork has to be disassemble every time.  And it won't help if the spring can't go stiffer.

I end up ditching the R fork and go with the SPR fork....  Now my set of R forks has been sitting in basement reminding me of all the time I spend to try to make it work...

[Steveog]

Thanks, Rick. Yeah, I took the lighter wheels comment to be a joke, based on your comment about priorities in spending money on micro-blue. Patricularly when he said, “Paint them”. My comments that followed were more examples of absurd spending, when I’m dealing with a blown engine. It’s all good. Your opinion is always welcome.

Yorkee - I’m on my phone, so sending pics is a bitch. I too had many dead ends trying to find TZR specific fork upgrades, so I went old school. Cut 20mm from springs, used a 1”, 20mm PVC spacer at the bottom of the fork tube and added the spec amount of Maxima 10 weight fluid. This worked wonders and is not the same as adding pre-load. I left pre-load on three bands from the top of the fork. Is it as good as a race-prepped Ohlins fork? Of course not, but there are no chicken strips on my front tyres. I “feel” exactly what the bike is doing, now. Much less “braking dive”. It cost about $20 and improved the front by 50%.

Now, for the rear, I used a NASCAR trick of adding a hard rubber do-nut to the top of the rear spring. This stiffened the spring-rate. It did not use up pre-load. Obviously, better, maybe 20% improvement. The stock shock is 27 years old. It obviously need a replacement, but fixing the motor has now taken on top priority. I will try to post pics of my suspension mods. Next couple of days are hectic. Hope this helps.

Steve

[Steveog]

Yorkee - Here's some pics of my suspension mods.

The fork spring is self explanatory. Used a Dremel tool to cut through the spring, then smoothed and cleaned out the area that would contact the spacer. Adding a washer between spring and PVC spacer would be a good touch, but this was only a test. Will cut an aluminum spacer and add washer after engine is rebuilt. Until I get faster, an expensive fork seems irrelevant.

The do-nut for rear spring is shown, as it was cut and then installed. Snug fit is crucial. This is industrial strength, very hard rubber. An entire track day showed no abrasion or restrictions to the shock. The do-nut was held in-place by two large cable ties. Again, as a test. The best solution is a new spring and shock, but this works for virtually no added expense if you DIY.

Both mods were obvious improvements for track duty over the relatively "soft" 3xv R model's suspension. Well worth the effort.

A complete tear down and cleaning of all parts in the fork are crucial. I used kerosene and washed all parts before re-installing. Be sure to clean out all the crap collected at bottom of fork tube. Let it soak in kerosene overnight, if possible. Then clean it out with a wooden dowel and paper towels. Follow the manual or any standard damper rod assembly process for hints on purging air. There are many posts on how to add fluid to exact levels for a 3xv1 fork here on the forum. I used Warwick's suggestion of 116mm to fluid from top of a collapsed fork to rim of fork without spring. Its a potentially messy process, but not technically difficult. 

Good luck.

[yorkee]

Yorkee - Here's some pics of my suspension mods.

The fork spring is self explanatory. Used a Dremel tool to cut through the spring, then smoothed and cleaned out the area that would contact the spacer. Adding a washer between spring and PVC spacer would be a good touch, but this was only a test. Will cut an aluminum spacer and add washer after engine is rebuilt. Until I get faster, an expensive fork seems irrelevant.

The do-nut for rear spring is shown, as it was cut and then installed. Snug fit is crucial. This is industrial strength, very hard rubber. An entire track day showed no abrasion or restrictions to the shock. The do-nut was held in-place by two large cable ties. Again, as a test. The best solution is a new spring and shock, but this works for virtually no added expense if you DIY.

Both mods were obvious improvements for track duty over the relatively "soft" 3xv R model's suspension. Well worth the effort.

A complete tear down and cleaning of all parts in the fork are crucial. I used kerosene and washed all parts before re-installing. Be sure to clean out all the crap collected at bottom of fork tube. Let it soak in kerosene overnight, if possible. Then clean it out with a wooden dowel and paper towels. Follow the manual or any standard damper rod assembly process for hints on purging air. There are many posts on how to add fluid to exact levels for a 3xv1 fork here on the forum. I used Warwick's suggestion of 116mm to fluid from top of a collapsed fork to rim of fork without spring. Its a potentially messy process, but not technically difficult. 

Good luck.

ha!  cutting a few coil and replace with a solid spacer, that will improve the spring rate... That's a good trick!  I like how you do the rear as well, similar effect as the front.  Thanks for sharing! 

[Crank]

Yorkee - I’m on my phone, so sending pics is a bitch. I too had many dead ends trying to find TZR specific fork upgrades, so I went old school. Cut 20mm from springs, used a 1”, 20mm PVC spacer at the bottom of the fork tube and added the spec amount of Maxima 10 weight fluid. This worked wonders and is not the same as adding pre-load. I left pre-load on three bands from the top of the fork. Is it as good as a race-prepped Ohlins fork? Of course not, but there are no chicken strips on my front tyres. I “feel” exactly what the bike is doing, now. Much less “braking dive”. It cost about $20 and improved the front by 50%.

Hi Steve, do you mind if I ask how much you weigh with relevance to the above fork mod. Thanks Scott