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Mat Oxley 1986 IOM TT


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Messages - idr5c

#1
Did you replace the condensers when you did the points? I've had a bad condenser behave like this, work fine and then start missing/cutting out when warm. 
#2
WMRRA Round 1 is in the books! Lots of wind and insane weather made it a challenging round. The weather forecast also scared off a lot of riders, Vintage included. Between no shows and attrition (mechanical and practice crashes) we ended up with only 4 vintage bikes on grid  :confusing2: WMRRA did change our gridding up this year so the Vintage crew race as a wave with the smaller modern bikes so at least we had some people to dice with.



I only had practice on Saturday so I volunteered for corner work in the afternoon. Was fun to zoom my 71' R5 street bike up to T12! Only picked up one bike, but it was my pal Tico so that kinda sucks. Between wet practice and 30-40mph gusts/squalls all afternoon it was exciting for the racers and the corner workers.










Sunday morning practice came around and the track was mixed damp/dry but still cold from the evening. My friend Duncan binned his Seeley/Westlake in T3 so that was another V750 competitor out.

Race 1 went well. The front half of the track was warm, dry, and sunny. The back half was pouring rain with standing puddles  :eek:. On the sighting lap I thought "Oh shit here we go".  I got the first and only good start I've ever gotten with this new engine and left everyone at the line. It was pretty weird to run full wet pace from T4 to T12 and then flat out T13 through T3. I've never experienced anything like it. Ended up with first but only had one other 750 I was racing against.

Race 2 was fully dry and so the game was on to chase down the Ninjas! I did manage to reel in a few of them (their wave starts 10s before ours) and to my complete surprise I was running a solid 3rd place laptime for the ULWSS class! That was kinda fun actually. I also lost a silencer. She got real loud on one side!

Only action shot I have, sorry about the watermark. Not paying for pics.





 
I had lots of issues with the front tire/front end this weekend so it's time to go back to the Avon AM26 race compound front and see how that does. If I can improve the front end chatter and get better grip on corner exit that will really help against the other 750's. 

It's only money $$$$$  :vroom:
#3
Race season is upon us again!  :olaf: 2021 was a weird race year for me. I had surgery in the Spring and that put me out of commission for most of the race weekends. I did take advantage of the latter half of the 2021 season to test some new components however and prepare for this year.

Garrett set me up with a great R5 top end. He made some porting tweaks from the prior 2020 350cc engine and trialed some ideas he had for making the engine work well for my skill level and our tracks. I also dialed in the jetting for his pipes.

Parts ready for the maestro


Parts back!


On the dyno


The new engine made good power so I spent the last rounds of 2021 learning to ride it. Other than forgetting that I still had my hillclimb gearing installed  :stupid-1:, things went well but I didn't mount a significant challenge in V750 having missed most of the rounds. I zoomed around and had a good time  :vroom:

So now the 2022 season is here and it's time to get serious about racing this new iteration of the bike. There are some things to address:

The Good
-The bike brakes well, seems reliable, and makes a lot of power   :burnout:

The Not So Good
-The higher speeds and power levels have pushed the handling of the bike in undesirable directions. I now have more chatter, some odd oscillation on fast corner exits, and overall the bike is not as settled.

I've got some ideas for the suspension and tires to get the bike settled out and I'm working on improving the aero so I can keep up with the big 750's at faster tracks like Portland.

WMRRA and OMRRA schedules are below and we have 4 shared rounds this season. As per usual, if you'd like to stop by please look me up in the pits. I'll be with the other vintage hooligans, just look for the 494 pit board. See you at the track  :wave:



#4
General Chatter / Re: Don't know if I believe this.
September 28, 2021, 03:17:14 PM
In the winter we had pump pre-mix at the local gas station when I was a kid, catered to the snowmobilers. 
#5
A bittersweet time, the 2020 WMRRA season comes to a close :( We were suppose to have a joint race round with OMRRA at PIR Sept 26-27th, but they bailed on us so our final official round of 2020 was cancelled. Disappointing to say the least but that's how it goes. I was feeling good about the round: Garrett's pipes and the fact that I have more laps at PIR than many of my 750 compatriots made me think I had a shot at mopping up the V750 class but I'll have to wait and try again next year. It's not official yet but by the points I ended up in 2nd for the championship  :whoop:.

And so the story ends................ or does it?  :evil2:

Faced with no circuit racing prospects I did what any self respecting racer would do: signed up for the Maryhill Loops Road vintage hillclimb!!! This event is put on by the Maryhill vintage car club and they welcome those of us with old bikes. It's an incredible experience, but very different than circuit racing. The "send it" mentality has no place on a road like this.





Lots of cool cars were there, I especially enjoyed the Bentley.









When all the runs were tallied up I came out with the 2nd fastest V750 class time!!!  :righteous: :metal: I was pretty stoked about that, having never run the course before.




And now the season is truly done. I owe Garrett some data regarding the engine and pipes and we need to develop our game plan for 2021. I expect a fairing, better ergos, and porting refinement will be part of that. I need to thank Garrett and the forum for helping make my race results possible  :clap:. As always, if you have an interest in motorcycle racing send me a message and my pit is always open. Until next time!



#6
Another race weekend done! Overall it was a success, but it didn't start out that way..... :umm:

Round 5 was at Pacific Raceways so I had a few things working against me: Pacific is a fast, flowing track with a long straight (compared to The Ridge) and my competition has been racing there much longer than I have. I really enjoy Pacific but I'm usually not as competitive there for some reason. For extra practice and setup time I signed up for the track day on Friday.

I spent most of Friday coming up to speed and figuring out my shifting/braking points. I was not as "on it" as I had hoped. With the new tires I'm still working up to pushing the front hard since the feedback they give is quite different than the Avons I've raced with prior. Duncan towed me around a bit and I got the back section put together well so I could carry lots of speed. My big competition for this weekend was a couple of well developed Nortons (+70hp) and a CR750.

I continued to dial things in during practice on Sat and Sun, did some practice starts, and then prepped for my races. The CR750 was off pace for some reason so I had that going for me. In the 1st race I boned the start (dammit! :bang:) and ended up in the back. Have I mentioned how difficult it is to get a good start with this engine? Anyway, I put the burners on and started passing people and closed in on the Nortons occupying 1st and 2nd place..... but then we came to T10 and went out onto the straight where they zoomed away. I reeled them back in during the next lap but they pulled me pretty good on the next straight. And so it went, lap after lap. I pushed until I almost binned it in T9 and at that point I realized I had a secure 3rd... maybe it was time to go for the bronze.

I got a much better start in Race 2 and used the fortuitous presence of a DOHC CB750 to box out one of the Nortons into T1. I put my head down and really pushed: late into T3, fast momentum lines through T5-6, sliding the front on the exit of T7, flat out through T8, and made it over halfway down the straight but the Norton would not be denied and he came zooming past. The chase had also lit a fire under his ass and he put in some solid laps afterward so I wasn't able to challenge him again. A lonely 3rd it was.

Not a win this weekend, but I didn't fall down OR hit anyone so that's a success I would say. More refinements will be needed.... stay tuned...


Trackday fun



Chasing the Nortons out of T10


On to the straight


Rolling onto the throttle out of T2






And a hot air ballon landed at the track!!!!


   

#7
Race Discussions / Re: MotoAmerica 2020 Schedule
August 31, 2020, 04:45:02 PM
Just got back from working the Washington round, lots of fun  :toot:
#8
Quote from: 1976RD400C on August 18, 2020, 05:51:54 PM
Wow, excellent results for the maiden voyage, sounds like the R5 will dominate. :clap:

We will see, some of the fast CR750's didn't make this round but I least I know what to shoot for.
#9
Quote from: pdxjim on August 17, 2020, 04:48:07 PM
Fantastic writeup Stephen!

Pretty sure my buddy Austin McCabe (snaggletooth77x on here) was up there on his 690 powered KTM 390 racing against the Kramers.

He was! 3 pits down from me. I saw his dirty & beat up KTM loaded in a pickup so I think he binned it at some point during the weekend. The Kramers are fast for sure, but it was fun to see DiBrino mow them down with an old SV650. That guy is un-freaking-believable.   
#10
What a weekend! I was a little apprehensive because I didn't have much time on the bike and there have been a lot of changes: different front end, front brakes, tires, top end, primary ratio, 6 speed...etc. Even the track was different since The Ridge added a chicane to the front straight. But in the end, there is only one way to get a bike sorted: go ride it !  :vroom:

It was hot for WA this past weekend, 98F in my pits that afternoon. First practice went well: I didn't hit anybody or fall down, plus the bike didn't seize :dawg:. All my shift & braking points were different so I spent most of the time feeling out where I could use my newfound power and how to keep the engine above 7.5k rpm so I could get good drive out of the turns. Once I got that worked out I began pushing my braking points closer and doing more trail braking. In all of this I neglected to do a practice start... doh!

1st race: I got a terrible start (see above mistake)  :'( and the rest of the 750 pack zoomed away. This engine/carb combo is not the easiest to launch and I need to practice that more. I worked my way up to 3rd place behind Duncan's Seeley-Westlake but didn't really have a solid move in mind to get by him so I tucked in to learn his riding style and get a plan. Then in Lap 4 he went wide in T6 (big carousel turn) just as I was practicing closing up on him at corner entry, so I swooped in for a clean inside pass and got on the gas early. I knew he was slower through T8 so I blitzed through there at svelte Yamaha twin appropriate speeds and gapped him. He reeled me in a bit on the WOT run to T11, but I went in deeper and used T11-16 to pull a big gap. Since they added the chicane and shortened the front straight, his straight line pull was less of an advantage and I maintained the position to take 2nd. The 1st place bike was on a CR750 replica and was waaaay out front.

2nd race: I got a better start and left with the pack. The winner of the 1st race was out with a mechanical issue so I got to thinking that I might be able to win if I got my head screwed on straight. Of course, Duncan had the same idea so I worked my ass off to try and pass him. By the start of Lap 5 I was ready to accept 2nd place: I was hot, tired, beat, and didn't have much left. Right about that time Duncan got on the binders early for the chicane so I stepped out of his draft, braked late, and made the pass entering the chicane. I hodged up the turns but he did as well so I didn't immediately get passed again and now had clear track. I put the burners on, gapped him through T2-4 and consolidated 1st place  :toot:

Garrett and I have lots of work to do to develop this bike and engine, but it was a great start! I can't thank him enough for sharing his experience and skills to make this happen  :clap: . I am tired, and that's all I've got for now.


Chasing Duncan through the chicane




#11
Quote from: Yamaha 179 on August 13, 2020, 08:36:00 PM
It has been my experience that the needle reduces he flow of gas more than the slide reduces the air flow therefore leaning out the mixture.  Less gas but almost the same amount of air = seizure.
Lyn Garland
PS: I didn't say 7/8 throttle, I said close the throttle just a bit; just ease off a tad.

Bingo, that's the info I needed. Lyn's right and I used the technique this weekend at the track. My main jet was still a little rich after working down from blubbery, and when I'd ease back on the throttle from WOT the bike would pull a little harder. Went down a size and all was well. Thanks Lyn!


Quote from: m in sc on August 13, 2020, 05:06:50 PM
i mean i did say:

however, it DOES sound lean.


Yep, you sure did.
#12
Quote from: m in sc on August 13, 2020, 02:53:22 PM
YES. LEAN.

Now THAT is a clear answer!!  :clap: Many thanks.
#13
Quote from: m in sc on August 13, 2020, 02:28:08 PM
could also be fuel feed issue. had same problem with my lc, had to go to 3.5mm? needle seats at wide open. only did it by the time i was wot at top of 5th gear, 6th would stall out. took forever to diagnose..

always err on the side of going richer on the main for tests like this. IF it gets worse, then you know its too fat. however, it DOES sound lean. but dont disregard how fast the bowl fills vs how fast its being used.  what size are your mains? if over 300, then, look at needle seat and verify hole size.

Not asking about issues with a particular bike, just the tuning technique in general.

Does anybody actually have experience with this tuning technique?
#14
I'm having a brain fart regarding a tuning technique that I have used for years  :umm:, hoping someone on the board can set me straight. Not sure how I managed to forget this rule of thumb... Lyn told me about this a decade or so ago and I've used it ever since.

Once the bike will pull cleanly on the MJ (no blubbering), I will go to WOT in top gear and hold it there. As the speed levels out, I'll back off to 7/8 throttle or so and see if the engine picks up a bit.

If the engine picks up a bit, does that indicate the MJ is a little rich or lean?
#15
Quote from: sav0r on August 11, 2020, 12:29:26 PM
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.

:clap: This  :clap: 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.