107 cu inch Mountain Motor!

[grbrown]

Originally Posted by db133

Can you please inform me of how the gearing was changed, how much it cost and how it has improved your Dyna. The reason I ask is because on a recent dyno tune top speed was 125mph ! I feel sure and we were advised a lower gearing would be of more use. Any info on this subject will be appreciated tc...:-)

As Dave has pointed out, much of your question is answered above.

I am guessing that the 125mph you mention, by being done on a dyno, was limited by the bike's gearing, in other words, in still air it could not rev out fully in top gear, which indicates the extent of the over-gearing it suffers from.

When riding that same bike on the road (sorry officer, the track) with wind resistance it would not achieve that high a speed, but with the lowered gearing we have, ours it is now likely to get very close to peak rpm in top gear.

For the sort of riding my wife does, bless her, all this is of no consequence! What it means to her is that the damned thing pulls away far more readily in first gear and rolls on like a freight train in top from ordinary road speeds, instead of thinking about it.

It is worth remembering that new Harleys suffer a number of problems, partly to do with exhaust emission, but also noise. Fuel mixture is very lean, which to improve performance should be undone, either by remapping the fuel injection or with a carb jet kit. The inlet is seriously restricted by using a very quiet airbox, which should be undone at the same time as the previous mod. Also ignition timing is not optimum, to keep engine noise down at low road speeds, which can also be sorted. Obviously the silencers are very quiet and restrictive. On top of that lot the gearing is very high, to reduce engine speed at noise-metering road speeds.

So when making mods to a standard bike, all the above should be considered. In the case of our Dyna we have done the jets, filter and silencers, plus the gearing, which has achieved my ambition of making my wife's bike more user friendly. She used to struggle with the thing in various ways, which is now sorted, although I now wonder if only changing the gearing might have achieved what I was after.

However, while my wife will never use the outer reaches of her bike's performance, I reckon we chaps should sort all the things in my list, including the gearing.

[simonDyna]

All looking very good Graham. Are you enjoying it?

[grbrown]

Originally Posted by simonDeuce

All looking very good Graham. Are you enjoying it?

Hi Simon,

In short, of the recent mods, the TrueTrack 'missing link' stabilizer has transformed the handling, which Matt described as the tightest handling dresser he has ridden! A great improvement. You should consider fitting something like it to your Dyna! My wife's now has front and rear stabilizers and handles much better. I will try and post some photos of both bikes soon.

The heavier clutch spring and, probably, the M6 tensioner, have somehow contrived to greatly improve clutch smoothness and takeup, although I am still getting used to the greater effort to use it. Another result!

Of the engine, it looks and sounds great, but I will hold my judgement for the time being, as I am not impressed with it. I have done about 700 miles at present. Bearing in mind I am also running in a new XB12R, both bikes claiming 102bhp, the contrast is dramatic - the one willing, the other reluctant. More news as the miles roll by and my assessment develops!

[michael_dinwiddy]

Sorry to hear your S&S motor is reluctant, mine gust wants to go.

perhaps the carb needs a retune.

[grbrown]

Originally Posted by michael_dinwiddy

Sorry to hear your S&S motor is reluctant, mine gust wants to go.

perhaps the carb needs a retune.

Hi Michael,

Its ironic that I planned this change long and hard, while I gather you had yours dumped on you! My new engine certainly doesn't leave me ecstatic in the same way my old 89 inch did when newly built. So I am pleased to hear you are happy with your 107 - I wish I was with mine!

I won't make any other comments for the time being until I have a better handle on the 'problem', if indeed I have one.

[simonDyna]

Guys, what ignitions/carbs/pipes are you running?

[michael_dinwiddy]

The motor come set up from factory with its own ignition, you do have to fit single fire coils though, and by pass most of the Harley wiring.

It also comes with a super E carb jetted for the purpose, just some fine tuning needed. They include a new vacuum things and all the bits needed.

Pipes; well thats a matter of personal choice, I've got a 2 into 1 V&H jobbie with very little in the way of baffle, don't know what GB runs.

[simonDyna]

I'm presuming its the IST ignition you have and wondering if you have the same revision/release versions of software/base settings.

Yes, pipes are very subjective and I've had good results with several different 2-1 systems on S&S builds.

I'm running the stock coil on mine albeit a TC dyna and it works well.

[michael_dinwiddy]

not sure about Gb but I have the stock ignition system, the more expensive 'learning' one give an extra years guarantee, but I was under the impression that the ignition system should not be tampered with.

[grbrown]

Originally Posted by grbrown

I won't make any other comments for the time being until I have a better handle on the 'problem', if indeed I have one.

Mine is an IST and was installed by the importer, with S&S single fire coil and new Samson true duals, plus a few other 'essentials'. Apart from patting it when it was in its box I haven't touched it, just ridden it!