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And the same issues exist for the Hyosung setup as they do for every other swap, you still need spring rate and damping corrections to get everything where it needs to be. Most forgo that work, which IMO is why swaps generally aren't that much, if any, of an improvement over stock. Granted the stock RD forks are about as garbage as you can get, but tuned up they seem to be okay. So doing a swap isn't some magic bullet.

This  I'm astonished how many bikes I've blown past on the track that had a fancy USD front end but no setup work put into it, while I have the "shitty" (their words, not mine) stock SV forks with the correct springs, oil and preload for me.

So, I got a box of parts from Garrett.......





Nothing too crazy here, but they do look nice! I wonder how they run? Only one way to find out 





Assembly and squish measurements. My base gaskets were a little thicker so the squish ended up at 0.038" (was shooting for 0.030").




Got my carb situation sorted out using an RD350 high top throttle junction and cables, plus a spacer that I machined. I will be running the cables that John @EC sells specifically for this combination after the upcoming race round.






Then we were here! Did some jetting work today and I am pleased with the results. This thing rips! I can't wait to get it on the track. Now to get my numbers back on and finish the safety wire.

 

Thanks John, I'll call today to get the right cables on order.

For this weekend I figured out that I could use a RD350 junction block and cables, but then they were too long so I machined a spacer to take up the slack at the junction end. Not the most elegant solution but it will work until the proper cables arrive.

Thanks everyone!

I've run into a snag on my racebike prep, hoping the brain trust can

I'm switching to a ported R5 top end and VM30's (large frame type) and I realized last night that the stock throttle setup doesn't seem to have the needed adjustment/travel to pull these carbs. I'm going to disassemble the junction block today and see if I can get more travel.

Can the stock R5 throttle setup work with these carbs? If not, I'll need to convince John to 2-day ship one of these   

https://www.economycycle.com/shop/yamaha-rz-350/frame-related-yamaha-rz-350/cables-yamaha-rz-350/vm30-38-throttle-and-cable-kit-not-for-tm/

Are you guys allowed to do any serious port work?

Yes, engine modifications are open. They do need to be reasonable for the period (no flatslides, etc.) and adhere to the displacement limits. 

Things are happening fast now  . Garrett has been making chips getting my cylinders and heads together. He is planning to ship them Wed.

Port/sleeve alignment was terrible!




Ah, much better!




Also......






I too have been busy getting my crank together and trued. Cleaning up this case has been a major PITA. Whatever sealant the last person used was really hard to remove! Also this engine was apparently run on castor so it's got that gunk in the crank area.







Sorting jets is tedious..

Watching from Washington with great interest  go get 'em!

We'll see!!!! V750 has some serious competition: the combination of well developed bikes and experienced riders means I'll have to work my ass off to catch them. Mick Hart was collecting points and podiums on a factory Laverda long before I was even a thing. But they all do have valves and as we know in the enlightened 2T forum, valves are for toilets.   

Crankin'! I'm building the new engine on an RD350 lower end I had laying around.





This one was crusty as hell, but new parts are on the way to get it ready for a new life  .

For the engine I decided to seek professional help. I knew an R5 350cc top end was in order but I was unsure what direction to take the porting and how far. I initially thought about using the TR3 port specs as a starting point, but I was concerned with both the reliability of the engine and my ability to ride it. I reached out to Garrett (GRA2Strokes) for advice and after some conversation about what I was trying to achieve we settled on a plan: He would port the top end, not a full on roadrace port job but something to give me more up top and take advantage of my pipes and a bigger set of carbs. He would also cut the heads and make good use of the high octane fuel I run. Carbs are VM30's, with the spigots turned down to fit in the stock boots.

Before


After, almost done

To be competitive the DS7 is going to need significant upgrades, but as Kevin Cameron said "Simplicity and light weight are never out of place in racing". On the plus side the DS7 is much lighter than the CB's (268lbs vs. 400+lbs), narrower, has better geometry, and is easier to make it handle well. The negatives are it is down on power (they make 80+hp), currently doesn't stop that well, and gives up a huge amount of displacement for the 750 class. The strategy is simple: a well sorted disc front end so I can charge deep and trailbrake into corners while maximizing my theoretical mid-corner speed advantage AND enough smooth power to get after it before they do on corner exit and stay in the draft on the longer straights. A fairing is also in the works for eking out those last few mph.

The front end is pretty straightforward. I had found set of TX500 forks, triple, and front wheel a while back, so I re-laced the wheel with an 18" rim, rebuilt the forks, put a fresh Conti CR3 on there. Jamie @ Sonic Springs helped me choose a spring rate and they are winding those as we speak. For grins I went with a dual disc setup, mostly so I could use the spare 1st Gen SV650 brake setup I had laying around. We'll see how it works, but I may go to a single disc/RD caliper later on to save weight. Those discs are heavy!!!!

The pandemic has delayed our roadrace season a bit here in the PNW, but we are finally on the track again! 2020 has held lots of surprises, including a significant injury for me back in January that I am still recovering from. That said, I am getting serious about my next WMRRA race build so it's time to post up some progress.

I've successfully campaigned  in the V250 and V500 classes over the past few years, but it's time for a new challenge. Initially I thought about the V160/175 class, but those losers submitted a rule change to keep 2 strokes out (I think they were sore about that OMRRA guy with the CT-1 that spanked them), so my attention turned to the V750 class......... >:D.

750 Vintage allows disc brakes in WMRRA (and OMRRA) and is dominated by SOHC CB750's with the occasional Seeley-Westlake, Norton, CB720 (550 bored/stroked), GT750, and so on. While a stock CB750 isn't that concerning on the track, most of these are CR750 replicas with fully built engines so it will be a real challenge to bring the fight to the front runners on the DS7. For 2020 I've mothballed the SV650 so I can focus on getting the DS7 updated and dialed in.

Great ideas! I pulled the cover and zoomed around, no sticking of the cam. Clearance in the idle position is in spec. I need to pull the side cover to freshen up the clutch (has the classic R5 slip) so I may just swap the pump, but I hate to throw parts at it.

I recently pieced together a basket case 71' R5 that I got awhile back. It's had a storied history, but it's all there and runs well. Anyway, prior to startup I put on new oil injection lines (feed and delivery), bled the pump, and everything appeared to be working well (cam turns, plunger works up and down, oil advanced up the lines, etc.). On my test ride though, I was getting lots of smoke, way more than my 72' R5. This bike has 14k miles on it so I figured it was just the pipes burning off, but it never died down and was mosquito fogging everywhere I went.

After 25 miles or so of test riding I looped the injection lines back to the tank, capped the fittings on the jugs, and filled it with 32:1 premix. Smoke dissipated within 5 miles and no more issues.

Hmmmmm... I've never had an oil pump fail, much less flowing too much. Pump plunger still moves as expected (up and drops to the cam position). What am I missing here? 

The WMRRA race season is finally going to start!  We will be racing at Pacific Raceways this weekend (July 10-12th). I'll be working the track since my leg and ankle are still recovering, but my pits are open for anyone that wants to stop by.

It's good, watched it a couple days ago. Of course all this free content became available..... after I had renewed my VideoPass