Motorycle Tune-up- WOW

[Nick R]

The other day my dad took our 31,700 mile (new to us) Honda Shadow VT500C to a local shop to get a new rear tire, and change fluids, spark plugs, air filter, etc.

Well, we got it back today. Holy cow.

We thought it was normal, but before even in first gear it would struggle to accelerate, and would never actually hit redline of 9,500RPM. IT wouldn't go higher than 7500, and it would struggle to get to and do 55, 60.

Well now, it just pulls hard, having ridden it before we were shocked. It was like they put a whole new engine in it. It will easily do highway speeds now, and the acceleration is pretty blistering. 9,000RPM is attainable with absolutely no drama. It's such a huge difference.

Would never have believed that a basic tuneup would have such a huge difference on performance.

 

[OilNerd]

Good to hear it's running great. Guess you'll have to add it to your sig now!

 

[ABerns]

For at least the stuff I've owned as far as modern cars, it takes a LONG time of neglect to run so bad that a tune-up makes a huge difference.

On motorcycles, for whatever reason, it seems that it doesn't take too long before a tune-up makes a big difference. And the deterioration sneaks up on you - you get a tune-up, think about how great it runs, and then ride it a lot. It falls off a little at a time, until you are running bad again and you forgot all about it. The good part - it's like getting a new bike every few years

 

[Eddie]

Sounds like the poor engine was seriously neglected. Shame

 

[Nick R]

Oh yeah I forgot to mention, dad had them rebuild and clean the carburetor, that might have had something to do with it too I'm sure.

 

[dwcopple]

I'd hate to see that repair bill

 

[Nick R]

It was actually only about $400, not bad at all.

 

[IndyIan]

Sounds like something was really clogged up before, even a 500 should feel pretty quick compared to most cars.
How's your brakes doing? Should only need 1 or 2 fingers on the brake lever to get the back end very light. In a straight line stop the back brake is hardly worth the concentration it takes away from using the front to max.

 

[dwcopple]

Originally Posted By: Nick R
It was actually only about $400, not bad at all.
Only about half the bike's actual value...no not too bad at all...LOL

 

[Mik]

Originally Posted By: ABerns
For at least the stuff I've owned as far as modern cars, it takes a LONG time of neglect to run so bad that a tune-up makes a huge difference.

On motorcycles, for whatever reason, it seems that it doesn't take too long before a tune-up makes a big difference.


Quite simply, motorcyles are generally in a MUCH higher state of tune (the exception big lunker cruisers notably Hogs,...), which in turn makes them much more sensitive (and reactive) to changes in tuning brought on by dirty air filters, ....

 

[boraticus]

Rebuild and clean the carburetor? Why?

They could have just waved a bottle of MMO or other magic elixir over it to cure it's problems!!!

 

[dwendt44]

Originally Posted By: boraticus
Rebuild and clean the carburetor? Why?

They could have just waved a bottle of MMO or other magic elixir over it to cure it's problems!!!

That may have been a joke post, but that actually works.
I've had cycles that were slightly neglected and dosing with SeaFoam (in my case) cleaned the carbs good enough that I had to turn the idle down about 150 rpm.

The 'CLEAN THE CARBS' mantra appears, I often wonder if that's not a money issue for the dealer/mechanic.
Autos go 100,000 miles without major carb work back when they had carburetors. Unless the engine won't run at all, try a strong dose of SeaFoam first.
That and a new fuel filter is often all that's needed.

 

[JT1]

Originally Posted By: dwendt44




The 'CLEAN THE CARBS' mantra appears, I often wonder if that's not a money issue for the dealer/mechanic.
Autos go 100,000 miles without major carb work back when they had carburetors. Unless the engine won't run at all, try a strong dose of SeaFoam first.
That and a new fuel filter is often all that's needed.


Most cars don't sit all winter long building up varnish and oxidization in the carb.

 

[Bladecutter]

Originally Posted By: Nick R
Oh yeah I forgot to mention, dad had them rebuild and clean the carburetor, that might have had something to do with it too I'm sure.


That probably was exactly what the bike needed worked on.

When motorcycles sit with gasoline in the carbs for a long period of time, the gas turns to varnish, and will plug up the pilot jet, the metering ports, or in some cases, the main jets.

Sometimes, you can get away with just getting a cleaner into the carbs, other times, you have to physically remove the jets, and clean them by hand, and then spray cleaner through the ports in the carbs until you have cleaner spraying out of the proper locations.

I've done many a carb over the years, and have seen some so bad, that replacing the pilot and main jets, along with emulsion tubes, were the only solution to a bad running bike.

With an older bike, like this one, you might have to also replace the float bowl seal, if the old one was dry and brittle, otherwise you might have a fuel leak right on top of your hot engine if you reuse it.

BC.

 

[mechtech2]

Scooter carbs almost always benefit from cleaning. Especially if they are stored [which most are in winter!].
Their idle passages are tiny, and any gunk or residue makes big running changes. Stuck floats [open or closed]are common, too.

 

[ComfyShorts]

I've seen this post word for word posted on another forum...nick you aware?

 

[beanoil]

The carb was your issue. With ethanol in fuel, it does not take long for deposits to form in carb passages and jets. No doubt in my mind you have deposit build up in the mains, leaning the fuel mix out. Most decent shops will also remove the EPA anti tamper plugs and tune the low speed circuit while the carbs are off the bike. Syncing both carbs with vacuum sticks after reinstall makes a difference too. And I am a huge fan of MMO in carbed bikes for many reasons. Carry a small bottle with you and add about 2 ounces every fillup. The performance you have right now will still be there 3 years from now.

 

[08_SHELBY]

Seafoam has done wonders for my 87 Voyager. That and a new set of plugs made a world of difference