How high can we rev the 680cc Rotax!?

[@waynewagner7953]

You can definitely rev it to 10k safely just requires Flat Track Factory to do some more r&d. I’m thinking plain bearing oil feed crank reinforced cases pankl rod and a custom designed slipper piston under milled for weight reduction. And if your gonna go that far your obviously gonna need to fit a larger clutch assembly to handle power increase which will require custom milled cases. And the transmission gear fatigue also becomes a factor but that can also be fixed by any good edm machine shop for a fair price I’m sure. Also I almost forgot probably going to need to add oil squirters probably one more for under piston to control added heat also going to have to make sure engine doesn’t wet sump. So a deep sump would be required also an oil cooler would probably be necessary. This is all that needs to be done.

[@sammyhalbert]

I'll get the guys on it! Let me know if you think of anything else ;)

[@shanelivingston3573]

Justin has been running up to 10k rpm for decades

[@EduardoCabreira]

Always nice to see you guys just chilling in the garage in such a relaxed ambient... only talking bikes and trash talking... as you do! ahahahah. As for the rev limiter... Show us the line and the RPM´s when you dyno it (no need to show the power figures to the competition!)

[@sammyhalbert]

Good feedback, sounds like another content piece for the Rotax will be needed!

[@robertyoung1843]

100% agree on 40psi on a fresh mounted tire till your ready to go. IMO it helps set bead and stretch tire. Settle at 9500 rpm’s Sammy! Fans have spoken.

[@jaydee659]

I had to go to about 90 psi to get my Maxxis DTR1 to seat. I got up to 60psi and after some googling I saw that some people with off road tires might have to go to 100psi. I was scared lol. Just kept watching the one spot it wasn’t seated and it was creeping on then POP it seated. The other side had seated already at around 75psi. I does have a tube on an old 80s 17” spoked rim. Have had it resting at 35psi for a couple weeks. Racing this weekend.

[@sammyhalbert]

Yep! I just gotta remember to drop that tire psi before I ride haha and hopefully Mike lets us bump the limiter up to at least that!

[@seeker156]

I think you should look at the Dyno. Potentially change gearing to the track.

[@markgiraldes4062]

My old 500 Rotax didn’t have a counterbalancer far as I know and it revved great also when I flatracked in the 70’s we dropped our right peg and shifter so maybe set up the same way for right hand turns would love to get on Rossi’s track you’ll never forget it enjoy !🤬😎👍

[@raganracing7361]

im not used to the limiter on a rotax but it does sound pretty cool i wont lie

[@sammyhalbert]

haha revving higher would sound cooler!

[@brandonbarabas4631]

Let that thing eat Mike we crank are rotax snowmobile engines to 9800 you should be able to do it lol. Good luck this year guys!!

[@sammyhalbert]

haha exactly! Thanks cheers

[@RJPerez-g3c]

Ti valves + ti retainers & ti Rod & lighten the piston with the correct length stepped header & intake track . everything being equal More rpm = more HP but You also need the correct valve springs or it will float the valves then the valves have sex with the piston which you don’t want.

[@sammyhalbert]

Yea RJ sounds like a plan! $$$

[@RJPerez-g3c]

@ you know cash & Candy make the world go round mate, you better get started making more content for your OF page which I will pass on the free membership but thanks anyway 😂

[@markgiraldes4062]

Definitely need’s some more on top ! Well if he won’t let you shift gears ! Maybe lighten the crank a little with a longer rod bring lots of sprocket’s ! Totally envious of your situation ! 🤬😎🇺🇸👍

[@smokey2135]

Let it Rev! This stuff is Gold!!

[@farmerkevin]

I do agree the limiter needs to be bumped up a bit, but I have no clue how much this engine costs. Any estimate on the cost of Michael's Rotax?

[@needmetal3221]

I'll bet 8-10 grand with the head

[@sammyhalbert]

Horsepower costs money, how fast do ya wanna go!? Haha I think he prob spent a pretty penny on it atleast 6-9 grand

[@dlcklovingood8547]

I have 1989 ron wood rotax engine In a champion frame

[@stevenhall2138]

I say the limiter needs to be upped a little bit!

[@sammyhalbert]

👏

[@TraceyLindsay-Sine]

Yup let it eat 🚴🏁

[@sammyhalbert]

💯

[@AaronMullins-q8t]

“ I’m too pretty to get dirty” 😂 Love the shop talk! Great video!

[@sammyhalbert]

haha yep! Thank you

[@outlaw7x77]

lol...easy for Sammy to say...TWIST IT!!! "You provide the engines"....a couple more beers and I bet it would run WAY better with it revving @11,000...Yeah baby!!!

[@sammyhalbert]

hahaha exactly ! Let er eatttt

[@uguyssss]

My rotax was a 500 so i dont really know ho hi a 680 would rev. When i was a jr we were allowed 500 singles or 750 twins with restrictors.But never really woryed about revs.

[@sammyhalbert]

Yea different time back then right! Cool we can still race some of the same bikes from back in the day.

[@needmetal3221]

@@uguyssss I can't even ride a mxer. Rotax framers are perfect. They square off the corner just right and tractor out

[@PeteN95]

Small block Chevys rev 10k at the drag strip no problem. I think the Rotax could handle a couple seconds! Same size pistons.

[@sammyhalbert]

Great point!

[@Nort79u]

Let the Rotax sing… Elliott probably still has cases.. Nort👍

[@sammyhalbert]

I like the sound of that tune!

[@america1723]

How about 400 more rpm

[@OklahomaRider]

17000 rpm on the rev limiter!

[@henrybobswillikers]

Nice vid Guys !

[@ryanknutson912]

If he won't raise the limiter maybe talk him into supplying a 450 framer. 😉👊✊

[@sammyhalbert]

We want that Rotax powaaaaa

[@MrBradmond]

Gotta finish to win. I'd trust Mike and let him set the limit. If you hit the limit so soon, can't you adjust gearing a little?

[@sammyhalbert]

Yeah, definitely been adjusting the gearing all the time to try and keep it off the limiter but when I wack her wide open it likes to get up there quick.

[@DavidDavid-zq7zx]

Massage the front brake on the right handers. if you could have raced an Ascot tt you would have been forced to learn it or you woulda had your ass handed to ya. also gear the limiter out of the equation. or like you said let her eat/ breath. old school says the limiter is in your right hand.

[@sammyhalbert]

Good suggestion, I've been playing with that more, rubbing the front brakes through the turn.

[@billymartin-q5e]

Old rev limiter was floating the valves

[@sammyhalbert]

Exactly!

[@johnsolimine1164]

...scream it, or ride it off the bottom... that is the question

[@jaydee659]

Gear it longer lol. In my limited engine knowledge, I personally don’t think being on the limiter is good for an engine. Still dumping fuel through, but not firing the plug. So And yeah, it sounds dumb too lol. Just reached the end of the video, yes take it to the dyno, see where power falls off! Dyno video!!!

[@sammyhalbert]

Yea I wouldn't think a big engine like that would like the way its hitting the limiter, Dyno video is a great idea!

[@shawntorrez6722]

9850

[@needmetal3221]

That motor has to be 5 grand not counting the head. I would be careful.

[@sammyhalbert]

It is pretty pricey, for sure.

[@dwightbernheimer331]

Agree on 9700😂😂😂😂😂😂😂😂😂😂😂

[@america1723]

Rev it higher. It’s a race bike

[@CraigBierman]

Revvv it up!!!

[@sammyhalbert]

🙌

[@brianbartlow563]

10,600

[@sammyhalbert]

Right! That would sound so good

[@codytoddy]

I can’t watch another video of you bangin the revy halfway down the straight. I’ll leave!

[@sammyhalbert]

haha yes exactly! Can't have that

[@handyalbert11]

I think you just gotta take a couple teeth off the rear

[@sammyhalbert]

You ride it then Andy hahaha

[@handyalbert11]

@sammyhalbert I'd probably never be able to touch the rev limiter

[@uguyssss]

I think Mike is kind of a cry baby.

[@FlatTrackFactory]

I def cry when I see the invoice after an over rev. Please send tissues. Kleenex brand. Thanks.

[@sammyhalbert]

hahaha cry on Mike, we will have to start a go fund me for ya if she blows at 10k