Ah, the joys of a tune-up....

If it's broken or just needs tweaked

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nickjtc
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Ah, the joys of a tune-up....

Postby nickjtc » Mon Jul 31, 2006 9:11 pm

Yes, I know all of these observations are blindingly obvious, but this was my first ever post-sohc tuneup epiphany.

Did a valve adjustment, oil/filter change, carb balance, adjusted the timing, and changed the rear tyre on the 650 on Saturday. WOW, what a transformation; it's like riding a new bike!

On the ride home on Friday (440km), pre-tuneup, the bike would wander and squirm whenever I crossed over the centre lines when passing, vibrated to the point of numb fingers and toes at anything over 5,500rpm, and generally sulked if I tried to rev it out.

On the ride back today (also 440km) the bike feels really planted on the road, actually revs willingly (took it up to 9,000rpm through the gears for the very first time since I have owned it), and is smooth as silk at my usual cruising speeds.

And it seems to be mechanically quieter....but that could be the post-tuneup good vibes.

What makes it all the more satisfying is that it was all my own work. It reinforces again how great these bikes are and how 'user friendly' they can be.

Incidentally, the carb balancer I use came off eBay:

http://cgi.ebay.com/NEW-Motorcycle-Carb ... dZViewItem

I was sceptical when I first saw it since it's only a few lengths of tubing, two small ball bearings, and a couple of screw-in adaptors for the vacuum outlet in the carbs. You can only adjust one carb at a time along with the 'reference' one, but even so the whole job only took me 15 minutes.
.....to be myself, a pattern for others.

1979 CB650
1971 Norton Commando
1968 CB175

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Chris
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Postby Chris » Mon Jul 31, 2006 9:36 pm

Congratulations on your tune-up/success. Thanks for the eBay link.
1980 CB650c

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Volker_P
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Re: Ah, the joys of a tune-up....

Postby Volker_P » Tue Aug 01, 2006 2:05 am

That's really great to enjoy the sucees of your own work. I agree that the CB is a quite user-friendly motorcycle with quite obvious technical solutions. I think this is one of my reasons to keep it in spite of the quite old-fashioned chassis.
My speedometer worm run dry and broke last week, so check and lubricate it (also revolution indicator). Lubrication of the gas wire is also important as the plastic part in the trottle may break if it runs too hard.

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nickjtc
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Re: Ah, the joys of a tune-up....

Postby nickjtc » Tue Aug 01, 2006 10:35 am

Volker_P wrote:That's really great to enjoy the sucees of your own work. I agree that the CB is a quite user-friendly motorcycle with quite obvious technical solutions. I think this is one of my reasons to keep it in spite of the quite old-fashioned chassis.
My speedometer worm run dry and broke last week, so check and lubricate it (also revolution indicator). Lubrication of the gas wire is also important as the plastic part in the trottle may break if it runs too hard.


Thanks for the tip, Volker.
.....to be myself, a pattern for others.



1979 CB650

1971 Norton Commando

1968 CB175

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Cteodorski
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Postby Cteodorski » Tue Aug 01, 2006 12:27 pm

Your timing couldn't be better -- I've been sitting here with the Clymer manual in my hands considering running through their eninge tune-up routine. I figure it's time that I dive in and learn more -- given the absolute suck-a-tude of my former mechanic.

I was just looking over the list of tools required and trying to figure out what I needed and what I already had.

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nickjtc
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Tools for tune-up

Postby nickjtc » Tue Aug 01, 2006 3:17 pm

The basic bike tool kit can be used for a lot of the piddly stuff, like undoing the rear axle nut to adjust the chain. I have a simple set of metric open and ring-end wrenches, a set of metric sockets (1/4" and 3/8" drives), a good set of feeler gauges and a couple of good screwdrivers. And the carb balancer. That covers about everything needed to work on the 650.

I'm thinking about getting a cheap timing light to get the timing spot-on, but doing it statically seems to have worked this time.

I have a Honda valve/tappet clearance adjuster on order, not because a wrench and screwdriver combo does not work, but just because......
.....to be myself, a pattern for others.



1979 CB650

1971 Norton Commando

1968 CB175

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Cteodorski
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Postby Cteodorski » Tue Aug 01, 2006 8:58 pm

Is it worthwhile to pick up a compression tester? How about a carb balancer?

I just want to make sure I have everything I need before I get started...

Guest

Postby Guest » Tue Aug 01, 2006 9:28 pm

Cteodorski wrote:Is it worthwhile to pick up a compression tester? How about a carb balancer?


I would say a carb balancer is a must, since it can be used at every tuneup. A compression tester is probably a good idea, too, but how often will you use it?

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nickjtc
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Tools

Postby nickjtc » Tue Aug 01, 2006 9:29 pm

Guest was me. Sorry.
.....to be myself, a pattern for others.



1979 CB650

1971 Norton Commando

1968 CB175

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Cteodorski
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Postby Cteodorski » Tue Aug 01, 2006 9:32 pm

And another question while I'm on the topic...

Can anyone explain to me the difference between the D8EA and D7EA NGK plugs?

And which should my bike be using?

I ask because I think my local honda shop sold me the wrong thing....

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Chris
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Postby Chris » Tue Aug 01, 2006 11:42 pm

According to this chart http://www.spark-plugs.co.uk/pages/technical/ngkjpg.htm at http://www.spark-plugs.co.uk/index.htm the D7EA is a hotter plug. Be sure to check out the FAQ and Technical Section for more info on spark plugs. I don't remember if someone in here steered me to this site or if it was somebody outside of this forum. If it was someone in here... thanks :)
1980 CB650c

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Volker_P
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Re: Ah, the joys of a tune-up....

Postby Volker_P » Wed Aug 02, 2006 1:28 am

A hotter plug may be used if your plugs get fouled/black in spite of everything being set up correctly. But usually there is something else wrong if "8" does not work and changing to another value is just curing the symptoms.
But it also may depend on the bikes usage. In case you run it exclusively on short daily trips to work, a "7" could make sense at a correct setup.

To the tools:
I think it is not worth to buy a own compression tester, that's something you use once when you get the bike to have an idea about the engine conditions and then maybe much later when it is close to fall apart and you want to check whether new pistons are necessary (but you already know they are :P).

Carbs syncronization: I did it ten years or so ago after I had to separate the carbs as I had to replace the O-rings in the connecting pipes in between. Since then it just runs. As it still idles smoothly well below 1000rpm I guess my synchronization cannot be too bad (or my rev counter reads completely wrong at low rpm :lol: ). I do not remember exactly, but I had only one gauge and blocked the lines successively. This has the advantage that you have almost no requirements on absolute accuracy of the gauge, only reproducibility has to be allright. To get the same accuracy with four gauges, they must have a certain quality which you have to pay for of course. It may be worth to have a carb balancer if you like to do exhaust/jetting experiments, otherwise you do it once and it is allright.

What I really consider important is to have a small enough torque wrench, you need a range from about 8Nm (cylinder head cover) to about 30Nm (cylinder head bolts). There are many more soft threads in this engine where a torque wrench is helpful to avoid trouble and helicoil horror. Be prepared that the O-rings at both sides of the cylinder head will leak and like to be replaced periodically (30tkm or so). Basically, even the accuracy is not that important if you have the possibility to calibrate it once against a professional torque wrench. However you should never use it to open bolts as (low torque) calibration might get lost then.

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Cteodorski
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Postby Cteodorski » Wed Aug 02, 2006 8:34 am

What I really consider important is to have a small enough torque wrench, you need a range from about 8Nm (cylinder head cover) to about 30Nm (cylinder head bolts). There are many more soft threads in this engine where a torque wrench is helpful to avoid trouble and helicoil horror. Be prepared that the O-rings at both sides of the cylinder head will leak and like to be replaced periodically (30tkm or so).


Finding something as low as 8Nm (6 ft-lbs) seems pretty difficult.... At least from what I've seen online -- I do see a ton of really cheap-o torque wrenches that go this low -- but I'm skeptical of the quality based on the price

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Volker_P
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Re: Ah, the joys of a tune-up....

Postby Volker_P » Wed Aug 02, 2006 9:05 am

Cteodorski wrote: Finding something as low as 8Nm (6 ft-lbs) seems pretty difficult.... At least from what I've seen online -- I do see a ton of really cheap-o torque wrenches that go this low -- but I'm skeptical of the quality based on the price

Yes, you really hit the point. For this reason you could use a quite cheap torque wrench only after you checked it against a professional one. At least if they work just by a torsion reading (additional mechanical stuff is dangerous) you can do some quite permanent calibration. But avoid opening bolts after you did that and also do not go out of range in the tightening direction.

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Chris
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Postby Chris » Wed Aug 02, 2006 9:53 am

I also found a really good article on spark plugs at wikipedia that touches on heat ranges among other things: http://en.wikipedia.org/wiki/Spark_plug
1980 CB650c


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