ubly minibike drags june 4-5
- Thread starter outlaw fab shop
- Start date
- Tags drags june minibike ubly
We will be going Saturday which is better for test and tune.
Usually a better crowd on Sat, plus there is a ride afterwards; assuming you have a rider bike.
I heard last year's Saturday after-ride was a blast.
I'm just bringing the drag bike which has a fuel range of 1/8 mile plus a little for startup and return road.
Usually a better crowd on Sat, plus there is a ride afterwards; assuming you have a rider bike.
I heard last year's Saturday after-ride was a blast.
I'm just bringing the drag bike which has a fuel range of 1/8 mile plus a little for startup and return road.
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Ubly Dragway 4812 S Ubly Rd, Ubly, MI - - Google Maps
On Sunday they have the minibike finals starting at 2 PM.
Last year their was 5-6 classes based on original engine HP.
i.e. 3HP - 5HP - 6.5HP - 8.0HP - unlimited, etc.
Not sure what the classes are this year, maybe someone can chime in...
If you just want to get a timeslip and some cool video, bring it on Saturday. Then you can tell all your buddies how fast your mini is.
Plus you get to practice racing on a real track. Not this hand waving, jumping start, LA way of racing.
Even with a slow mini that does 20MPH you will have a great time for $10!
On Sunday they have the minibike finals starting at 2 PM.
Last year their was 5-6 classes based on original engine HP.
i.e. 3HP - 5HP - 6.5HP - 8.0HP - unlimited, etc.
Not sure what the classes are this year, maybe someone can chime in...
If you just want to get a timeslip and some cool video, bring it on Saturday. Then you can tell all your buddies how fast your mini is.
Plus you get to practice racing on a real track. Not this hand waving, jumping start, LA way of racing.
Even with a slow mini that does 20MPH you will have a great time for $10!
here's some aftermath video of my motor
Motor seemed to be down on power about 5mph, but it still was running good. Its a gx200 with big valve head and 2.992 bore that I bought off of mdb. I was running it on gas and it went 11'20s at 62mph with me a 250lbs rider. It went 68mph @ 10'30s with my 150lb jockey. This is 1/8th mile of course.
I made about ten passes and then boom. Got it home to find out it broke the exhaust valve off at the valve head. Here is video of the aftermath.
YouTube - exhaust valve destruction on gx200 and some of my toys‏
Motor seemed to be down on power about 5mph, but it still was running good. Its a gx200 with big valve head and 2.992 bore that I bought off of mdb. I was running it on gas and it went 11'20s at 62mph with me a 250lbs rider. It went 68mph @ 10'30s with my 150lb jockey. This is 1/8th mile of course.
I made about ten passes and then boom. Got it home to find out it broke the exhaust valve off at the valve head. Here is video of the aftermath.
YouTube - exhaust valve destruction on gx200 and some of my toys‏
Valves just dont drop the head off, piston had to have hit it, one piece valves have way more tensile strength then the spring could ever create. Now if the springs get weak, you could run into valve float or what we call valve bounce, the 2 worst things you could do, bounce will fatigue the valve causing it to break in the weakest area, that being the undercut. Float just introduces the valve head to the piston in a bad way...:wink:
Not sure what he had in there, but we can get you set back up, head looks to have taken a beating, better check the intake seat as well....
I dont know how long springs should stay in, but MDB said they were fresh when I bought the motor from him. I only made less than 25 passes in 1/8th mile so I would hope they last longer than that
JD, The intake seat does'nt look to good either.
Heres a pic of valve stem, notice how half of the stem has been turned down.
JD, The intake seat does'nt look to good either.
Heres a pic of valve stem, notice how half of the stem has been turned down.