Modern Vespa

We just drove > 1100 miles from Denver, Colorado, USA to Union Pier, Michigan, with our two GTS 300 Super Sport scooters on a trailer and now they run really rough and want to stall at low rpms.

We always use premium 91 octane gas in Colorado (5500 foot altitude).

I don't want to harm them and they usually run great. Should I worry?
- is it just from trailering, vibration, etc. and there is air in the lines?
- is it a low altitude problem, due to their setup in Colorado?
- should we drive it off, and put in lower octane gas?
- we're only in Michigan for 5 more days, should we get something adjusted?

Hoping to ride a lot on our little 5 day vacation, but we're bummed that they're running so strange.

Tips/advice appreciated
~Chip and Arlene

I'm no mechanic but....

Were they covered?
Was the ride bumpy?
Did you check for any loose cables/spark plug?
Gummed up intake filter from dust?

Just my 2¢

Are they stalling because of the gas from Michigan? Or are you still running gas from home and stalling?

I'll take a shot in the dark and say that you need to reset the ecu for the lower altitude. I "think" you do this by disconnecting the battery but am not sure. If you do, disconnect the negative first and then the positive. When reconnecting, connect the positive first and then the negative. Hopefully someone who knows will chime in.

Altitude 603 feet @ union pier mi

I would try the battery disconnect trick, if that does not work let them idle a while and see what happens, or just try and ride them.

My guess is the ecu is trying to adjust.

+1 on ECU (Engine Control Unit)

If you had ridden them out there, the scoots would have adjusted gradually, and you wouldn't have noticed anything unusual. Let them idle on their stands for awhile, with an occasional rev up. That should do the trick, if you don't want to disconnect the battery.

I am hauling a couple scoots out to California next week. We will ride them at Arches National Park, Utah, and other places along the way, and are ready for the same issue.

Thanks for the replies. Just woke up and will get going on this.
To answer the questions:
- same Colorado gas is running in the mostly full tanks
- they rode on an uncovered trailer, not very bumpy ride on I80
- not dusty

I'll check cables but think the ecu sounds like a good candidate, I'll idle it a while then ride a bit today.

Then we'll try the battery disconnect trick.
Thanks everybody!!!

When you trailer them home, start 'em up and let them idle in the trailer all the way to Colorado so the ECU can slowly adapt.

(Giggles inanely and hits the "Just Walk Away Button")

Wife's GTS has always run a hair rough... mine seems good today after 3 minute idle on stand.

So i worked on hers:
Battery disconnect and reconnect trick performed.
Checked spark plug wires etc, all good and tight.

Started rough, ran shitty, let it idle a few minutes, until a tad better. Hit the throttle a few times and had some sputtering, then rode it for 10 minutes. 1st block at 25mph, then up to 35. Suddenly seemed better... Got on Red Arrow highway for a mile or two at 55mph, and it seems much much better as I come to a stop, it no longer dies or knocks.

It's Michigan. Just drop them off at my house and they will be OK. Forever.

P.S.
Don't forget the titles

And red keys.

We've been seeing scoots with this problem after being trucked or trailered with a near full tank of gas. The gas splashes around and fills up the EVAP system causing stalling and rough running. Often with a check engine light from the O2 sensor trying to compensate for all the extra liquid fuel the engine is getting.

Most of these can be fixed by giving it the old "Italian tune-up".....wide open throttle top speed runs. It will pull the liquid fuel out of the EVAP system, and return it back to normal operation.

The barometric sensor (what compensates for altitude) is reset at every key ON. After a couple starts it should be already set for the higher altitudes.

Great post, AF1, from a non-amateur.

Good info AF1 Racing! Thank you for your input.

Very good advice and diagnostic knowledge going on here.

Scooter/bikes were not designed to be trailered. Sometimes they take a beating besides getting very dirty.

No need to run prem. in Denver, actually octane requirements are lower there

They just like to be ridden. Glad you got the problem solved. Now ride then some more. Got any pics of then? Yes i'm nosy but i like looking at people scooters. Ride safe.

Hope you get it sorted....My club is going to Bike Time in Muskegon July 20th, and am having a get together there.....
We have members riding up the lakeshore, meeting the main group in Grand Haven area....Hope you can make it!
http://www.grscooterclub.com/forum/phpBB3/viewtopic.php?f=7&t=2012

Here's a shot of our trailering fun while stopped in Chicago area to spring my 90 year old mom from assisted living to take her to Michigan...

It's a Kendon Standup trailer with 2 Harbor Freight chocks fitted on the rails. Great trailer...

Unfortunately the weather has completely sucked since we arrived. Rain, chilly, cloudy, and we're 1 block from the beach. We left Colorado's very high temps hoping they'd follow us to the lake. Oh we'll, at least the scoots are fun (and running fine again).

God bless your Mom. Scoots come and go, but...
People are forever.

Wish our bodies were as easy to fix and reset as your nice scoots.

Glad I came across this thread as I am just two weeks away from a 4000 km round trip vacation to PEI. I will make sure the tank is almost empty!!

Thanks for the pics. I want to see mom on the back of one of those scooters. I bet she'd love it.

This.

Needed to be quoted again just to bump it. Run the 87 while at altitude.

Seriously? Why is that? I'm loading my BV for Colorado Springs this weekend and will be riding for a week in the mountains. Thanks for our assistance/explanation on this matter.

I carried my BV 350 from middle Tennessee to Colorado Springs.

I arrived and on first attempt to start, bike was sluggish and didn't want to start. Eventually, it started and ran ok, but very sluggish, especially from 0-30 and the top end was around 73, well below normal.

Following advice in this thread, I have done the following:

- did the Italian tuneup, as proscribed by AF1 (several times)

- disconnect the battery

- cleaned air filter (it was dry and relatively clean)

- I (unfortunately, as I learned above) had a full tank of gas from Tennessee during travel, so I fear I may have fouled the evap canister.

I have used the tennessee gas, plus 2 tanks of Colorado gas - using regular, as strongly recommended above.

So, bottom line the bike is rideable, tho not as fun - made it to the top of Pikes Peak without embarrassing me, but was definitely lacking in power.

Ay other suggestions? I'm following through on my plans the next 3 days, including visits to Frisco, old Loveland pass, Mt Evans, Breck, Leadville, etc.

[/list]

PM me when you will be in Breck and I'll meet you for coffee or something though I've still got another week before I'll be cleared for riding.

TN_Sooner, although you may have other contributing factors an engine will lose approximately 3 percent of it's horsepower for every 1,000 feet that you go up in elevation. With Pikes peak being over 14,000 feet it would be normal to lose approximately 42 percent of your power at that altitude. This is a rough estimate. I think that there is a formula to calculate it. I also wonder if your spark plug got gas fouled.

Interesting and thank you for the feedback. However, I never noticed any difference traveling from TN (elev ~750 ft) into the Smokies (elev up to 6500 ft). At ~6300 ft in Colorado Springs, there is a significant loss in power.

I think you may be on to something on the plug.