Help! Surging issues!

Roscoe · Post by **Roscoe** » Wed Jul 04, 2012 4:23 pm

That is the only way I can think to explain it.

She seems to surge with power. It feels like a heartbeat almost. She will get a surge then back down then surge then back down. It is more of a power issue and not an electrical issue.

It happens anytime I ride her and not with any action that I do. It almost feels like the opposite of vapor lock (which she has done to me in this crazy heat).

I asked my local scooter club and they said that it could be a vacuum issue. I don't know how to go about fixing a hole in the vacuum tube because I can't seem to find replacement tubing anywhere so that makes be believe that there is no vacuum tube!

Anyone have any suggestions or questions that could help a gal figure this out?

Dean F · Post by **Dean F** » Wed Jul 04, 2012 4:40 pm

How many miles are on the Rat? Is it under warranty? Have you tried running some Seafoam through the system?

Roscoe · Post by **Roscoe** » Wed Jul 04, 2012 5:07 pm

My Rattler just sold yesterday and I now have an Italia 150 that is having the issues. Shes a 2009 and shes got 5k miles on her.

I have tried Seafoam in her. It doesn't really help.

Skootz Kabootz · Post by **Skootz Kabootz** » Wed Jul 04, 2012 5:09 pm

Sounds like it just needs its major service. At 5K it is due.

spr0k3t · Post by **spr0k3t** » Wed Jul 04, 2012 5:23 pm

The vacuum tubes can be found at a reasonable scooter shop. Just make sure they are good quality and can handle ethanol.

Dean F · Post by **Dean F** » Wed Jul 04, 2012 5:29 pm

IMHO take out the rollers (probably lots of flat spots) put in 18x14, 13 gram sliders, about $30.00 for the set.

pdxrita · Post by **pdxrita** » Wed Jul 04, 2012 5:58 pm

Yup. I'd check out the rollers. If they have flat spots, that's the sort of thing you'll feel. It's an easy fix.

illnoise · Post by **illnoise** » Wed Jul 04, 2012 6:53 pm

the ENGINE is surging, right? Like just raging at high revs occasionally? that's probably got nothin' to do with rollers.

I don't know of any "vacuum tube" but I don't know modern scooters that well…

But my bet is that it IS a vacuum issue, there's either an airleak in the engine cases, or the cylinder gaskets, or for some reason the airflow to the carburetor/efi is not right. I'd check any air intakes for caked up mud or debris, look for cracks in the rubber and plastic around the airbox, check your air filter, make sure the carb's not loose/warped, and look for dark oil/gas gunk leaking from any seams around the cylinder or engine cases.

Sadly, it could be a blown seal inside the engine, too. That's nothing Seafoam's going to help with, I'd take it to the shop.

Roscoe · Post by **Roscoe** » Wed Jul 04, 2012 7:56 pm

It is not revving like a maniac. Its nothing you can hear-- you can feel it. Its more of a pushing feeling. Like when you are riding a bike and someone pushes you a little harder. Kind of like that every couple of seconds. Its like a heartbeat. A down beat and an up beat. LOL--

Not any kind of speed or engine crazyness.

Skootz Kabootz · Post by **Skootz Kabootz** » Wed Jul 04, 2012 8:23 pm

Roscoe wrote:It is not revving like a maniac. Its nothing you can hear-- you can feel it. Its more of a pushing feeling. Like when you are riding a bike and someone pushes you a little harder. Kind of like that every couple of seconds. Its like a heartbeat. A down beat and an up beat. LOL--

Not any kind of speed or engine crazyness.

Mine had similar a symptom when I had the air box problem. You might try checking for any leaks from the air box through to the carb that could be allowing extra air into the mix. But that said, I stand by my original comment, it sounds to me like it just needs its regularly scheduled major service.

tortoise · Post by **tortoise** » Wed Jul 04, 2012 9:09 pm

In this thread the gremlin turned out to be a defective vacuum-operated fuel tank outlet valve (petcock), allowing fuel to bypass the carb via the intake manifold vacuum line. Pinch this vacuum line closed with a spring clamp and make a short test run to see if it makes any difference.

There is also a possibility that the carb diaphragm is defective. Might try running the engine up while on the center stand and observe if the slide is moving properly (may require an angled mirror and flashlight).

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Roscoe · Post by **Roscoe** » Tue Jul 10, 2012 3:21 am

Last night we chhanged the exhaust on the scoot and tonight it totally died on me while driving. Since this seems to be out of my league-- I am taking it in to get a full service check in the morning. I am really hoping everything goes well and it doesn't cost me an arm and a leg. I need them both to ride the scooter!

Cpequin · Post by **Cpequin** » Sat Sep 29, 2012 12:30 am

If you read this more than once from me, it's because I'm trying to get the word out:

I was having the engine light come on as well every day, and was beginning to have a "surge" issue...going 50 or 55, the bike wouldn't hold steady, it would surge forward and back, when holding the throttle steady. (my commute is on mostly parkways, 55-60 the norm, for 27 miles one way at least 1/2 hr of riding)

Turns out (apparently) the oil was overfilled. Sucked out a little more than 1/4 c to bring the level where the skinny end of the dipstick meets the fat part of the dipstick.

That was 4 days ago. Completely different scoot. Can go all day again and have tons of top end, takes going 55-60 for my commute with no engine light, "surge" problem is gone. So happy because for a while I was worried about my decision in getting the scooter.

I'm going to start doing my own fluids. But please please please check your levels, even if a dealership is doing the work.

Modern Buddy

Help! Surging issues!

Help! Surging issues!

Not a Rattler

surging

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