Tech Basics

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jenny
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Tech Basics

Postby jenny » Wed May 21, 2014 9:23 am

For ease of reference, this is a compilation of general tech/maintenance recommendations from various members of the Turbo Dork Scooter Network.

SPARK PLUGS/TIMING:

From Mikeh:
I've never trusted or been a fan of "plug chops" or checking the color of the spark plug.

The best way to tell if your motor is tuned right is to just ride it, listen to it, and smell the exhaust.

You can also check the timing with a timing gun to see if you are in the correct ball park with specs.

If the exhaust is smokey and it rides slow and cool you are probably running too rich.
If the exhaust is clean and the motor winds out very fast and the cylinder shroud gets too hot to touch, then you're too lean.

If it backfires.. then you have ignition happening too late, it probably will run cool and sluggish.
If it fires too early it may run hot and seize, but it will wind out faster.

The way on timing is to set it to factory recommended settings and vary it slightly from there. making sure to get good performance but not run it so hot that it explodes or backfires. it's a balancing act.

But I would not trust plug chops. When you kill the ignition and/or fuel to do the chop you will not get an accurate view of what is going on in there as the fuel mixture will still be getting sucked through the carb even if you turn the gas off (there is enough gas to let the engine run for about 30 seconds) So getting the fuel and spark to stop at the same time to get a good reading it not very likely.


From dirtyhandslopez:
All of the above Mike and also, the way to do plug chops, as told to people, is to WOT in third, then cut the ignition and turn off gas. Yeah, that's really good for a two stroke, get it hot then cut off the fuel that cools everything down. Kinda like coming off of the freeway, running full blast, then, shutting the throttle off, what you get is an insta seize. Run 'em and listen to 'em,smell em beat the hell out of them, but don't be shutting of the gas at high revs.



**********

STANDARD TORQUE SETTINGS:

From Mikeh:
BOLTS
5mm bolt or nut: 3.5-4.5 ft/lbs
6mm bolt or nut: 6-9 ft/lbs
7mm bolt or nut: 12-14.5 ft/lbs
8mm bolt or nut: 13-18 ft/lbs
10mm bolt or nut: 22-29 ft/lbs
12mm bolt or nut: 36-43 ft/lbs

SCREWS
5mm screw: 2.5-3.6 ft/lbs
6mm screw: 5-8 ft/lbs

FLANGE BOLTS
6mm flange bolt: 7-10 ft/lbs
8mm flange bolt: 17-22 ft/lbs
10mm flange bolt: 22-29 ft/lbs

ENGINE
Stator Screws: 2.17-2.89 ft/lbs
Kickstart Lever Nut: 16.64-18.81 ft/lbs
Coil Pickup mounting screws: 1.45-1.81 ft/lbs
Clutch Center Nut: 28.93-32.55 ft/lbs
Input Shaft Nut: 21.70-25.32 ft/lbs
Flywheel Rotor Nut:43.40-47.0t ft/lbs
Carb Sleeve Nuts: 11.57-14.47 ft/lbs
Clutch Cover Bolts: 4.34-5.79 ft/lbs
Cylinder Head Nuts: 12.30-15.91 ft/lbs
Exhaust Pipe Stub: 54.25-57.86 ft/lbs

FRAME AND SUSPENSION
Suspension unit mounting plate nuts: 14.5-19.5'ft/lbs
Suspension unit to mounting plate nut: 21.7-28.9 ft/lbs
Suspension unit lower mounting nuts: 14.5-19.5 ft/lbs
Steering head adjuster (preload): 4.34-5.06 ft/lbs
Steering head locknut: 36.2•43.4 ft/lbs
Handlebar pinch bolt: 21.7-28.9 ft/lbs
Rear suspension unit lower mounting bolt: 9.4-16.6 ft/lbs
Engine unit pivot unit:,44.1-54.3 ft/lbs.
Front wheel hub nut: 43.4-72.3 ft/lbs
Rear wheel hub nut: 54.3-65.1 ft/lbs
Wheel mounting nuts: 14.5-19.5 ft/lbs
gimme that step-thru, yeah, cuz i need that.

epsato
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Re: Tech Basics

Postby epsato » Fri May 23, 2014 12:56 am

Very cool idea. I approve!

dirtyhandslopez
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Location: Richmond, VA.

Re: Tech Basics

Postby dirtyhandslopez » Sun May 25, 2014 7:48 pm

This is good Jenny.

Mike, one problem with the whole torqe setting part is that very few people actually own a torque wrench, that alone one that is calibrated.

As a general guide, 15ftlbs is a regular 3/8 rachet(in length) used until it is tight, but not straining on the wrachet. Two white knucles, not four :wink:
It's really best not to use anything over a 1/4 drive wrachet on any fastener under and including 5mm as you will tempted to torque down to hard. This is especially true if you have steel going into aluminum.
Always try to use a flat and a lock(spring) washer. Lock/spring washers operate correctly only in one direction. If they are fitted backwards, they will "unwind" when you do them up. Have a look at one, you will see that one end has a flair, that flair should pressed down into whatever it is you are trying to secure, not pulled up into the nut or bolt head.
That's not going anywhere

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Zeets
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Location: Kensington (for now)

Re: Tech Basics

Postby Zeets » Tue May 27, 2014 10:31 am

Generally, the correct torque is: tighten until spins freely, back off quarter turn.
Zayretow

70' Vespa Sprint (2009 LML power)
74' Yamaha RD350 (pinger)
2008 Suzuki DRZ-400SM (thumper)

dirtyhandslopez
Posts: 876
Joined: Thu May 01, 2008 1:12 am
Location: Richmond, VA.

Re: Tech Basics

Postby dirtyhandslopez » Tue May 27, 2014 3:30 pm

Huh?. How do you tighten something until it spins freely?

And I disagree.

That is most definately not what I was taught in the 7 years of mechanics school I payed for and attended.

You go ahead and do that and see the crap just start falling off of your scooter.

When a torque wrench is used, you do not torque to a desired specification and then loosen, what the hell would be the point of having a torque wrench?
That's not going anywhere

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Zeets
Posts: 905
Joined: Thu Aug 19, 2010 6:42 pm
Location: Kensington (for now)

Re: Tech Basics

Postby Zeets » Tue May 27, 2014 6:21 pm

It's an old bike shop joke...
Zayretow

70' Vespa Sprint (2009 LML power)
74' Yamaha RD350 (pinger)
2008 Suzuki DRZ-400SM (thumper)

dirtyhandslopez
Posts: 876
Joined: Thu May 01, 2008 1:12 am
Location: Richmond, VA.

Re: Tech Basics

Postby dirtyhandslopez » Tue May 27, 2014 11:45 pm

Would that be a bike shop that worked on old motorcycles or an old bike shop that had dust everywhere and worked on bicycles?

You got me good. Bastard :)
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