2 smoke DS's on pavement......?

[Twin-shocker]

If you ride enduro/mx bike like a trials bike, its going to get very hot, in exactly the same way as if its used at WOT for long periods on the road.

[peter650]

Originally Posted by Twin-shocker

If you ride enduro/mx bike like a trials bike, its going to get very hot, in exactly the same way as if its used at WOT for long periods on the road.

I am sure you are a top bloke, but your wrong.

[Twin-shocker]

Originally Posted by peter650

I am sure you are a top bloke, but your wrong.

If so then I wonder why MX-enduro bikes used WOT for long distances (beach racing is a good example), are jetted and set up to stop them seizing on the very long straights?

[tHEtREV]

So just don't ride with the throttle wide open.

You're asking for trouble doing that with most bikes on the street anyway, from the law if not mechanical...

[High Country Herb]

It has been a while since I spent much time on 2-strokes, but have seen them sieze from extended WOT use.

As a kid, we rode our 2-strokes to the next town all the time. We rode them as if we were switching gears the whole way. In other words, while riding in top gear, we would pull the clutch in and let off the throttle occasionally to give the piston a quick break. Fuel/oil mix was still drawn in through the carb, and this gave the motor lube while coasting (for about a half second). We did this about every 10 seconds, and avoided top speed runs (unless someone wanted to see our street license credentials).

2-stroke oils have come a long way since then, so there is probably less chance of siezure. Even if it happens, it isn't much work to swap the rings and/or piston.

[JWhitmore44]

I used to run my old DT250 35 miles to the next town. Crused 55 to 60 mph, speed limit was 55. Air cooled, oil injection, never heard of varying the rpm, pulling in the clutch, or applying the choke. It's a wonder I didn't go up in flames Are you really running with the throttle wrapped clear around? Find a comfortable cruising speed and don't rap it out tight. Unless you are running lean on the top end of the throttle opening I can't see where you would get into too much trouble. Both bikes you are talking about are water cooled aren't they? Thought those bikes were "enduro" types were it could see a long stretch of high speed through desert like conditions.

[peter650]

Originally Posted by Twin-shocker

If so then I wonder why MX-enduro bikes used WOT for long distances (beach racing is a good example), are jetted and set up to stop them seizing on the very long straights?

Gday Twin shocker he wants to ride his bike on the road. It is not the cooling system, thats going to be a problem. You can jet a 2 stroke MX motor to run on the street, & it will not over heat on the open road. If you have a exhaust port bridge, drill 2 holes in the piston. Most old MX 2 strokes will surge on the street, but you can fix that with jetting. Just look at all the old 2 stroke GP bikes. Cheers Peter

[peter650]

Originally Posted by JWhitmore44

I used to run my old DT250 35 miles to the next town. Crused 55 to 60 mph, speed limit was 55. Air cooled, oil injection, never heard of varying the rpm, pulling in the clutch, or applying the choke. It's a wonder I didn't go up in flames Are you really running with the throttle wrapped clear around? Find a comfortable cruising speed and don't rap it out tight. Unless you are running lean on the top end of the throttle opening I can't see where you would get into too much trouble. Both bikes you are talking about are water cooled aren't they? Thought those bikes were "enduro" types were it could see a long stretch of high speed through desert like conditions.

+1 on all the above

[Twin-shocker]

[QUOTE=peter650;19517731]Gday Twin shocker he wants to ride his bike on the road. It is not the cooling system, thats going to be a problem. You can jet a 2 stroke MX motor to run on the street, & it will not over heat on the open road. If you have a exhaust port bridge, drill 2 holes in the piston. Most old MX 2 strokes will surge on the street, but you can fix that with jetting. Just look at all the old 2 stroke GP bikes. Cheers Peter[/QUOTE

Riding on the road and beach racing are pretty much the same thing...........heat is what kills a 2T motor, and the reason for bigger jets is to provide a richer mixture which in most cases will lower temperatures enough to prevent seizing. If you take it easy though, the stock cooling system will be able to cope no problem..........but not WOT with stock size jets.

[MItrnsplnt]

Totally agree with what everyone is saying, and I appreciate all the info....I don't plan on riding at WOT on the road, I was just concerned about connecting trails with paved roads for extended stretches of 10-25 miles (which is what we recently did on our CO trip a few weeks back). Still trying to understand everything and get back to the 2T world (which I haven't done yet, but will be soon)....by having a bigger jet and making it richer in the carb to provide more lubrication for those longer stretches, wouldn't that give me a higher probability of fouling a plug when riding ST up in the mountains at a lower RPM's and not having the throttle wide open? Would a JD jet kit give me a good all around setting for roads and ST or is a matter of trying to mate bigger jets with what might currently be in the bike?

[peter650]

The jets do over lap, but out on the open road, your going to be on your main jet. The thing with dirt bikes, they jet them so they are crisp/snappy. You will loose a little throttle response, but nothing to about. Just remember the more oil, you mix in your gas, the leaner your bike will run.

[Twin-shocker]

Originally Posted by MItrnsplnt

Totally agree with what everyone is saying, and I appreciate all the info....I don't plan on riding at WOT on the road, I was just concerned about connecting trails with paved roads for extended stretches of 10-25 miles (which is what we recently did on our CO trip a few weeks back). Still trying to understand everything and get back to the 2T world (which I haven't done yet, but will be soon)....by having a bigger jet and making it richer in the carb to provide more lubrication for those longer stretches, wouldn't that give me a higher probability of fouling a plug when riding ST up in the mountains at a lower RPM's and not having the throttle wide open? Would a JD jet kit give me a good all around setting for roads and ST or is a matter of trying to mate bigger jets with what might currently be in the bike?

As I posted earlier bigger jets are fitted to provide a richer mixture to help motors run cooler, not for increased lubrication. If you dont plan on riding WOT, and take things easy and vary engine speed, then the the stock jetting will be fine.

[WVhillbilly]

On my EXC, in the woods the radiator barely gets warm. But I do notice the heat coming from it on the road.
I still don't run fast or anywhere near WOT on the road, and try to limit the amount of time I spend there.

Because that bike is really no fun on the street.

[pdxjim]

Originally Posted by Twin-shocker

Fitting bigger jets might stop a dirt bike seizing when its ridden on the road, but it wont alter the fact that the cooling system isnt designed to dissipate the amount of heat resulting from wide throttle openings for long periods of time.

Hogwash.

[Twin-shocker]

I wonder if you have ever ridden in the SSDT, where 2T dirt bikes cover a lot of miles on the road at wide throttle openings? Competitors in that event will be very interested to learn that overheating and seizure is not likely to be a problem!