The 'new' dirt bike.

71T Targa · 07-30-2010, 07:25 AM

Just picked up this 'new' dirt(y) bike for the kids. It'll be a step up from the 80cc four-stroke he's riding now. It's an '03, 85cc liquid cooled 2-stroke.

Just wanted to brag a little about how much fun he'll be having.

Tim Hancock · 07-30-2010, 08:43 AM

Nice..... My daughters each had modern 80cc liquidcooled MX bikes.... very fast when kept up in the power band.

Shawn 357 · 07-30-2010, 09:46 AM

Nice Honda!

M.D. Holloway · 07-30-2010, 09:50 AM

My Son wants that very bike! Very cool.

71T Targa · 07-30-2010, 10:10 AM

He doesn't know about it yet. I picked it up last night, and he'll get to see it for the first time when I get home from work today.

It's been a while since I've has a 2-stroke. What oil should I be using and at what ratio? I used to use yamalube at 50:1 in my 250.

Also, he said he was running ATF in the bottom end. Is this right?

WIL84911 · WIL84911's Garage

How old is your son? Are they allowed to ride them? My 15 year old's been bugging me about these.... including ATV's.. that's what I got for moving out on the burbs I guess. Thanks.

Tim Hancock · 07-30-2010, 10:31 AM

I always simply ran 10w40 in my gear boxes in all my 2-stroke race bikes and never had any problems. Yamalube is what I always used when I raced.... Now I use Amsoil 100:1 synthetic in all my dirtbikes/snowmobiles/weedeaters/ultralight etc (life is much simpler with only one type of pre-mix to keep stocked). I mix it more like 80:1 (1 small bottle to 4.5-5 gallons of gas. I have run it for the past 10 years or so and never have had a problem with plug fouling or engine wear (the ultralight has probably 300 hours on it running at 6-6.5k rpm nearly continuous). I like the Amsoil because I can buy it nearly everywhere. My MX bikes ran great on it and run them WFO most of the time using the clutch as my power delivery tool.

71T Targa · 07-30-2010, 10:35 AM

Quote:

Originally Posted by WIL84911

How old is your son? Are they allowed to ride them? My 15 year old's been bugging me about these.... including ATV's.. that's what I got for moving out on the burbs I guess. Thanks.

He' just about 11. I wouldn't have gotten this as his first bike. The kid that was selling it was 14 and had moved up.

I'm not sure what you mean by "Are they allowed to ride them?" If you asking about riding in town or in a development, then no, that wouldn't be a good idea. We have 3 acres, and live on a street with 15 houses where we all have 3 - 5 acres. So there is some space. We also have trails within an hour that we can go to.

Racerbvd · Racerbvd's Garage

I'm getting this this weekend!!!!

WIL84911 · WIL84911's Garage

Quote:

Originally Posted by 71T Targa

.........If you asking about riding in town or in a development, then no, that wouldn't be a good idea. We have 3 acres, and live on a street with 15 houses where we all have 3 - 5 acres. So there is some space. We also have trails within an hour that we can go to.

Yes that's what I meant... thanks.

71T Targa · 08-02-2010, 06:48 AM

Well the kid was super stoked with his 'new' bike. He ripped up the lawn all evening Friday, and Saturday we took it trail riding. He's having to adjust to the height and power, especially on the hills. Only dropped it once though and that was in a slow, sandy, rutted, right hander.

Picked up some 1.5 oz bubble packs of Amsoil 100:1 to try out. So far I am impressed with the burn and the looks of the plug. I mixed it at 85:1 (2 packs to 2 gallons)

Looking for track days now.

Tim Hancock · 08-02-2010, 07:14 AM

You probably already know this, but in case you don't....

Start the bike when cold with the choke then once running, turn the choke off as soon as possible to avoid fouling. I would rather have to keep turning the choke on/off at fast idle until it stays running rather than risk fouling a plug by leaving the choke on too long. I always made my girls sit on the bike while slowly warming it up with short medium throttle blips once off the choke until they could feel heat in the liquid cooled cylinder walls. Then I would allow them to motor off with occasional medium rpm runs for a minute or two until the bike was likely fully warmed up.

Running full throttle on a cold "liquid cooled" 2-stroke can cause cold seizure or scuffing due to the "closer fit" aluminum piston heating/expanding quicker than the still cold liquid cooled cylinder.

Every two stroke liquid machine we own has always been started following this warm-up procedure with excellant long term results and very minimal plug fouling issues.

If your son is already comfortable with using a clutch, as he gets faster he will need to learn about fanning the clutch to stay in the power band exiting turns while more or less keeping the throttle pinned WFO most of the way around a track.

71T Targa · 08-02-2010, 07:55 AM

Thanks Tim, I do make sure it's warmed up before it's really ridden. No choke needed to start though. Just a kick and then a few blips of the throttle while it's warming.

Tim Hancock · 08-02-2010, 08:17 AM

Quote:

Originally Posted by 71T Targa

No choke needed to start though. Just a kick and then a few blips of the throttle while it's warming.

hmmmm.... sounds like at least your idle speed jetting my be a bit rich as I have never had a somewhat modern era (90's to early 2000's 80's, 125's & 250's) liquid cooled MX bike that did not need the choke to start when cold. That said, if it is not fouling plugs and comes off idle fine, then I guess you are good to go.