Topic: Let's go roadracing...continuing saga

[bwaller]

That's what I do to pay the bills Frank, but it's getting more difficult. The difference between here and the Okanogan is the price of land. Growers your way can sell out for big bucks, here....not so much. 


Now back to those carbs.

[bwaller]

Back to larger pilots and these are the ticket, down to a 110 mainjet which is perfect for the bopping around I was doing today. It pulls like a train.

Two little issues, one rubber puck started leaking. I'll re-torque at the same time I fix that and the valves will need to be re-adjusted anyway. Plus I have one brake disc causing some oscillation on heavy braking. It almost seems like loose rivots, but I hope not, I spent a lot of time on those bloody rotors.

[kayaker43]

Hey Brent,  I'm thrilled to see another 550 hit the track, I would have let my project die if it weren't for the inspiration here. My problem is that my old racer was far from stock with a Bimota style rising rate single shock before Honda ever had one. Back then I could run it in Superbike and Formula classes and actually win. Now there's no competitive class for heavily modifed 550's. They either want you to run skinny tires stock frames and dual shocks, or they throw you in some open GP class with RG500's. I hear that situation has improved, its time for me to start reading rule books again. My biggest hangup is limited choice of 18 inch tire compounds and widths.

Your fairing looks just the right size, what's it from? I picked up a Dunstall 1/4 fairing from Airtech. I think they are the best classic cafe fairing as far as looks but the size you have looks more practical for racing. A BMW R90S fairing looks nice too and Airtech makes replicas.

I used a 400F tank on my old racer too, it slims the bike down a lot.

I can't get used to the modern trend toward huge bulbous bloated gas tanks,.. or tails that stick way out,.. or star wars styling,..  ohhh, don't get me started 

[bwaller]

I'm not up to scratch on anything other than production based classes, even then AHRMA's middleweight prod. class is for  stockers. USCRA & the VRRA allows for some tweaks.  Good luck finding a class to suit. Like Tintop and his Curtis monoshock chassis project, finding a class to compete is tough. I think some race associations are missing out on a lot of potential bikes on a grid.

That fairing was from a French company and by the sound of things may be a survivor from the seventies. I bought it from a guy on the Canadian west coast so it has been around. It's very light and I have the lowers, but they'll take more work to incorporate a bellypan.

I've been testing with your batteries. Too soon to say how long a four cell will last, but I'm hopeful one will be fine for a short sprint race.

How goes the big TZ restore?

[kayaker43]

I've been testing with your batteries. Too soon to say how long a four cell will last, but I'm hopeful one will be fine for a short sprint race.

How goes the big TZ restore?

The battery run time will depend a lot on the coils you use? The TZ750 restoration is kicking my butt,. or at least my wallet. Any parts I find usually come from the UK so the exchange rate and shipping kill me. Would you believe $1400 for some NOS swingarm bearings!! I'll be making replicas for those. I'll still get it on a track just to experience history, but its coming out too nice and too expensive to have any real fun with. 

After my wallet heals,.. I'll build an old honda racer to play with  Gotta use up those old yoshimura parts somehow? Instead of running some restricted class I would rather go with a full custom frame and suspension, modern tires, stupid big bore etc,.. then just race against myself behind the open class bikes and GP two strokes. Maybe by the time I get it done there will be a better class?

[turboguzzi]

kayaker,

narrow rims such as?  this bikes run extremely well on a 90/90-18 am20 avon front and the AM23 130/650-18 can work also on extremly narrow  rims due to their cantilever structure.

[bwaller]

I've got two sets of coils to choose from and based on if the dyno shows a difference between the two I'll decide. Pulse coils from a DOHC Honda 750 or Dyna 3ohm. I hope the Honda coils work with the small 550 chamber. I prefer these because of better wires and caps too. I'll check ignition current draw then.

I feel for you with the TZ stuff. It's a pure race machine for sure and the price tag to match. 
 

[kayaker43]

kayaker,

narrow rims such as?  this bikes run extremely well on a 90/90-18 am20 avon front and the AM23 130/650-18 can work also on extremly narrow  rims due to their cantilever structure.

I understand the Avons are good stuff but even a 130 tire seems narrow these days. I've been saving some vintage Dymags in case I decide to run 18's and they are fairly wide so maybe with an offset front sprocket I can run a 150 if the rules don't limit rim width  Like i said, I'm not up to speed on recent class rules.

[paulages]

A guy here in Portland, Gene "Doc" Brown, has tons of TZ parts left over form his race bikes. He has a whole garage that's just his race stuff he's had through the years (and he goes back far enough to have raced Hailwood when he was on the RC181...), and there is some great stuff in there. Factory expansion chambers, hand made replicas... I think he sold TZ750 last year for $35K or so, but he still has a couple TZ350s. If you need anything specific, PM me and I'll ask him. He knows what he's got and what it's worth, but some of that stuff is simply unobtainable. He has a TZ750 wheel he keeps on ebay (overpriced) just to get the attention of anyone out there looking for more of this stuff.



Anyway, sorry for the hijack Brent. I'll try to peek into my smoothbores tonight and see what's in them.

[paulages]

Ok Brent, here's what's in my 590:

15 pilots
122.5 mains
needle in middle clip

That said, I'm not totally certain that this jetting is perfect, as the story behind these carbs is a little murky. Apparently it was originally tuned to a set of Blue Magnum flat slides, and the runners/carbs that I have now were on the second 590 racer built at the same time. I only had it on the track once, with two stacks missing, and I only got to do a few laps before some dumbass on a brand new liter bike ran wide on a tight turn and sent everyone packing.

Hope this helps.

[bwaller]

There has been a bit of a snag. When I returned from my plug chop on Sunday there was a bit of oil showing. Thought it was a rubber sealing puck, but was actually the head gasket leaking and running down a stud. Three problems actually, one the sleeves had settled (like Paulages) two, the deck surfaces weren't perfectly flat, and three I'm not sure copper gaskets are "dead soft" as they arrive from the manufacturer.

Both head & cylinder were machined, but I never took the the time to check on a surface plate.  Both were high to the outside and I worked them flat on a plate. The outfit that bored the cylinders came highly recommended but has been one problem after another. First they bored too big, then I waited for them to replace sleeves and re-bore. When I got them back they hadn't bevelled the sleeve bottoms, and now obviously they didn't final press the sleeves when they replaced them and they sunk into the cylinder with a few heat cycles........never again for these guys. I thought about using something other than a copper gasket but I can't find anyone offering MLS at all or even fibre gaskets thinner than 0.043" stock. So I'll anneal this one and the engine can go back together.

Another issue than became evident is with oscillation under heavy braking. I mic'd the disc circumferences and they're within 0.0015" so I think I can live with that. I figure the best check is for wobble with one or both while on the bike with dial indicators on each disc face. I'll get to that soon. 

The plus side is the jetting is close enough to dyno now so, more to come......

[Tintop]

To bad about the oil leak issues, everything was going along so nicely.  Wonder if you thinned those disks out too much, and they are already starting to warp.  The dial indicator(s) will answer that.  Good news is the six speed seems to be working, as you haven't reported any issues.  Going to have to add that to the race bike's growing list of mods.

[turboguzzi]

mmm.... not nice. how about going to someone who can check sleeves are fully pressed, then shave the block and use a stock thicker gasket?

discs sound easier to sort out. maybe check their seating well on the hub? any trace of paint could throw them out a bit

[kayaker43]

I've seen that happen several times with the sleeves. Quite often its just because the corners weren't chamfered after machining the cylinder casting. Outside corners are always sharp unless you chamfer them but inside corners always have some tool radius causing a conflict. Shove a square shape into a round corner and it won't seat fully.

Also it just takes one stray glassbead or speck of sand to keep from seating. I'm not a big fan of abrasive blasting engine parts.

[bwaller]

The discs are fine, I did use a piece of aluminum sheet to make a spacer for one side and never thought to check for runout. I'll set up to indicate.

I already checked the sleeves and have reworked the head & cylinders with emery paper on a surface plate so hopefully I'm good to go again. I wish there were MLS gaskets available.

[Bill/BentON Racing]

Hang in there! You'll get it.The six speed all OK!Damn them new bike blues...sounds like a country song. ::)Dyno time soon...real interested.
Brent,one beautiful ride! 8)Bill.....off to work on Samauto's NBB's

[paulages]

Brent, I thought the same about my Cometic copper gasket when I got it. They said it was already annealed, and it seemed soft to me. However, I broke out the oxy/acetylene torch this past time and it got MUCH softer. I say gove it another try, unless you're sure that both surfaces are flat and true. I
never have problems with copper gaskets on British bikes.

Sorry to hear about your woes. Hope I didn't rub off on you.

[bwaller]

There's been a little water under the bridge since the last issues. The oil leak was addressed, discs redone and after some last minute set-up we made a track day at Shannonville where the first race will take place. I'm pleased with how the bike handled, the brakes are strong and I gained a trust for the great Avon race tires. The engine is strong and really pulled well through the different circuits but broke up around 9000 on the straight. Even jetting up the main only gained a bit. There was also a bit of oil showing from the same spot on the head gasket.

Two days later I had a dyno appointment and again installed larger mains, plus set both Dyna pickups airgap to 0.022" and retimed ignition to 30 degrees where it had been at the track. Once on the dyno it ran like crap, broke up @5500 and wouldn't rev cleanly no matter what I did to the carbs or ignition. It idled as well as it ever did though and ran on all four. Frustrated I wondered then if it was a pickup or the Dyna 2000 box itself, but why when it ran so well when thrashed two days earlier. Off home I went to work alone.

Luckily I have the same igniton on my 750 and when I exchanged the whole ignition plate it revved cleanly again. Bloody Dyna, those pick-ups didn't have three hours run time. That company needs to do something. I imagine parts are being produced elsewhere and in the last several years their reputation has suffered. I like what the D2000 offers with different maps and a rev limiter but it's hard to develop a trust. I'm going to call tomorrow AM and we'll see if they step up to replace.... and quickly.

After more carb work it still breaks up @ around 9K but I'm missing some jets before going bigger on the main. It almost acts like it's hitting the rev limiter even though the limiter is set @11,000. I need to wait for help and a drier afternoon and do some plug chops.

Does anyone have another suggestion, could v-stacks have a similar effect?                     

[scottly]

It almost acts like it's hitting the rev limiter even though the limiter is set @11,000.

Does anyone have another suggestion, could v-stacks have a similar effect?                     

Can you switch back to the stock points and mechanical advance? This might narrow it down to either the Dyna or the carbs.

[bwaller]

It almost acts like it's hitting the rev limiter even though the limiter is set @11,000.

Does anyone have another suggestion, could v-stacks have a similar effect?                     

Can you switch back to the stock points and mechanical advance? This might narrow it down to either the Dyna or the carbs.

No I'll work through this without points. I'll try the ignition box off my 750 first and see if it may well be defective too.

[scottly]

Since you are running a total loss system with a minimally sized battery, you may want to check the battery voltage with the motor running? 

[bwaller]

I mentioned it was showing a bit of oil again after I had flattened the surfaces. I never believed there was any gain in re-torquing copper head gaskets but since I had nothing to do this evening.....

As soon as I pulled the cover it was evident one of the sealing pucks was leaking and there was a touch of oil around the stud below. There is no quarantee the gasket isn't weeping some too but at least the puck won't now so that's a positive!

First race this weekend.

[tweakin]

Don't think I have chimed in yet, but this build is epic in my opinion.  I love everything you have done here and look forward to hearing the results of this weekends race.  Not as much about how well you placed but how much fun you had on that beaut.  Hope you get the oil leak worked out, I am sure you will.

-tweak

[bwaller]

scottly it's a good point. Last weekend was a good learning session with the Lithium batteries. I only had two 4-cell and they had to be used together to manage a thirty minute session. I know have another eight cell and can have one charging and ready to exchange. Great little batteries but "hit the wall" without much warning when voltage drops below a certain level. The engine acts just like it's run out of gas.

As part of my troubleshooting I installed a regular lead acid battery just to cover all the bases.... there was no need.

By the way tweakin, last weekends grin didn't come off until I got to the dyno. An absolute blast, plus vintage racers are among the best people anywhere. 

[Tintop]

+1 on the vintage racing crowd.

So that's Shannonville on the 4th / 5th?  Bit of a hike on the 400 but....