How to make her go ?

[Sibbo]

OK, introduction , my bike is a1983 ST, she's basically in good shape . Good handling, tires, brakes ..... great gearbox . She starts first touch of the button ..... but she's a little tired .

Now I didn't actually realise how tired until yesterday. I took a new V7 Guzzi for a test ride, it's a nice bike, a touch lighter than my ST but in almost every other way ,very,very similar. The same 5 speed box ,the same specified 50 hp and that's where I noticed it ! The difference must be about 15 hp ! Mine is slow by comparison and that's fair of course ,the Guzzi being 240 km old and mine 131000 km old .

So , how to remedy this ? I've just bought the bits to fit new rings and a valve reseat is likely. A carb rebuild ?

Will this short list get me close to my orginal 50 hp or are there other things that will need attention ?

BTW, the V7 is neat, a damn good bike for anyone who likes boxers but yearns for a brand new bike .

[Rob]

You need at least 1000cc pistons and jugs...

Seriously though, I think the correct first answer is compression and leakdown tests, to see whats what.
Then measuring ring gaps in the cylinder as Duane was describing to someone yesterday or so.

With all this newfound power, though, you may end up needing that new rear shock!

[SteveD]

Measure what you have first I guess.
Another angle, other than motor...

Does your old Boxer feel like an old dog? Fear not - it may just be asking for some attention to the preload settings of its wheel, swinging arm, and steering head bearings. A day spent setting up these bearings is a day well spent!

[Sibbo]

Steve, I'm entirely happy with the way she handles , possibly not as crisp as the V7 but good and I'm kinda used to her too.

What I want is my 50 hp back !!

OK, a leakdown test but I'm defintely doing rings as I think one of my oil rings is sus . I blow a little smoke, not enough to visibly use oil but visible from the pipe after a fast run.

[Rob]

From the fifth reply in this thread: viewtopic.php?f=1&t=8898&p=106484#p106484

What you want, besides a very light hone, is to examine the cylinder wear. It is always the most in the top 3-4 mm. If you can feel a tiny ridge with your fingernail, then I might measure it for wear. In your case, since it was working just fine, I probably wouldn't bother. You can learn how to measure it without any special tools on my website. W6REC.com If you wish to measure ring wear, remove the top ring and install it into the bottom of the cylinder where there is no wear. Measure the gap with feeler gauges. The gap should be .003" for each inch of piston diameter, or about .010" total. I probably would reuse it even if the showed .020" as it is so easy to remove later for more work.

[Zombie Master]

When you get your power back the handling will suffer.

[Mal S7]

Gday Sibbo,

I got to ride a friends V7 Sport last year in Nebraska. What a sweet motor. Absolutely loved that bike!



(Nebraska hasn't moved with the times very much, at least I didn't get shot off my horse)

Your R80 should be a close match in performance to a V7. Bob Bennett's R80 gets along like a bewdy, outruns my old R100. He had the motor rebuilt I recall.

My bike blows some visible smoke and uses about half litre of oil per 1000kms and I doubt I am getting the original performance from it. It has good compression and leak down figures though (as best as I could measure) so I don't believe that's definitive. I may pull it down this winter to see what needs doing.

cheers
Mal

[Sibbo]

Gday Sibbo,

I got to ride a friends V7 Sport last year in Nebraska. What a sweet motor. Absolutely loved that bike!



(Nebraska hasn't moved with the times very much, at least I didn't get shot off my horse)

Your R80 should be a close match in performance to a V7. Bob Bennett's R80 gets along like a bewdy, outruns my old R100. He had the motor rebuilt I recall.

My bike blows some visible smoke and uses about half litre of oil per 1000kms and I doubt I am getting the original performance from it. It has good compression and leak down figures though (as best as I could measure) so I don't believe that's definitive. I may pull it down this winter to see what needs doing.

cheers
Mal

Now there's a mystery, she sounds very much like mine .

There's a very pleasant and honest bloke in town who runs the local head machining shop and races Ducatis . I think a chat with him is on the menu.The V7 performance is what I WHAT!

I wonder what Bob's rebuild entailed ?

[Duane Ausherman]

To test burning oil is to run it at night with a person following you. Run it up and down against compression. A person following can see the blue haze far better than you might imagine. You will learn about the valve guides and rings.

[Rob]

To test burning oil is to run it at night with a person following you. Run it up and down against compression. A person following can see the blue haze far better than you might imagine. You will learn about the valve guides and rings.

Rings if it smokes on the throttle
Guides if it smokes off the throttle

Right?