Float like a butterfly...

**husaberg** · 2nd February 2016, 19:32

Originally Posted by F5 Dave

Yea I have the brake plate that goes right in, but the speedo drive is incorporated in the spacer on the other side. There isn't the room for such a spacer. Drive is tapped from the same side as the lever on std setup. Oh well,

Stinger
http://www.vintagebike.co.uk/wp-cont...25-stinger.jpg
GT185 although it looks some models have a torque arm or a tab
http://thmb.inkfrog.com/thumbn/indep....JPG=450&gap=1

the GN250 is on the off side.

**F5 Dave** · 3rd February 2016, 06:13

Oh that's interesting, maybe something to look at later, mines all fitted and I have to keep focused which is proving a bit difficult atm.

**F5 Dave** · 4th February 2016, 22:11

And I've zincd the wrong brake arm. Oh well silver paint for now.

Run the loom. My pictures weren't clear enough. About 80% connected, and about 80% of those I'm happy with. Faded colours and colour blind male, added to an old style loom with no blocks, just individual bullet connectors.

Might have to get the wife to check my matching. Else just check the other end of the loom wire I'm expecting it to be.

Have another bash later. Collect heads tomorrow I hope so some tedious measuring and machining to do, but then I can finally fit the engine.

**Drew** · 5th February 2016, 07:44

I admire your motivation man. Given the number of projects you've mentioned in the shed, this is coming along right quick.

**F5 Dave** · 5th February 2016, 18:50

Thanks its just been so hot. Dropped the chrome work off to Skiddy in upper hurt, some items like the iconic stinger covers and heat shields need brazing/fettling before final chrome. Needs a craftsman.

Grahame is a quiet achiever, but I showed up one day many years ago to find him working on the Ally Steve Roberts bike that preceded the plastic fantastic. Roberts complemented him on the resto.

Karl had planed the heads. Should end up ad 0.7 squish each. Now just to machine them to correct comm.

**Drew** · 6th February 2016, 05:29

This has been mentioned in the ESE thread I'm sure, but there is just too much info in there for me to retain any of it. Will just getting the squish right without doing any other work make it go better?

**F5 Dave** · 6th February 2016, 06:20

Squish bands work by placing a cool area of gas around the edge of the piston which promotes the exchange of heat to the relatively cool heads. If that area is too wide transfer is less efficient. It also makes the combustion chamber compact for quick burning.

The trade off is that gas in the squish area is never burnt. So reducing it to close to nothing means most gas mixture is available for power production.

On top of that I'll crank the compression up a tickle, but I certainly won't go crazy. Its an old bike and air cooled. But no point putting an engine back together if yer not going to make it faster

.

Also it will be a through the range increase rather than favouring top end.

**Drew** · 6th February 2016, 06:25

That makes sense. Cheers.

**F5 Dave** · 8th February 2016, 20:59

15.6:1 and 16:1

Maybe a little high.

First cut. Probably 13.5, but harder to add material.

**F5 Dave** · 9th February 2016, 21:14

Well it measured at 5.5cc. 12.3:1. Actually that'll do as is. Gave it a polish to just remove machining marks.

Next side I do by eye to match the other. 5.5cc. This never happens. The 300 took me about 7 cuts. Still I'll take that as a win.

Back of fag packet calculations make std about 10:1 but capable of running on dishwater and kero.

More fag packet guesses, should make, erm, hmm, well were talking say two low tuned air cooled 50s over bored. 4hp x2 + 25%. 10hp? Maybe I've added another. Could I hope for 12? This is going to be slow.

But light, and who cares?

**merv** · 9th February 2016, 21:47

Whatcha talking about Dave? Suzuki claimed the Stinger was a 15hp motorcycle in stock condition, are you saying they exaggerated well?

Back in the day the one we had did feel like it had that kind of power up top but it also had the feeling of quite a wide power band for a small twin giving the illusion it was rather flat.

**F5 Dave** · 10th February 2016, 06:03

Many years later the rotary valve GP125 made 13hp on a real dyno and it was considerably more advanced. So yes the exaggeration started early.

**Drew** · 10th February 2016, 06:46

Originally Posted by F5 Dave

Many years later the rotary valve GP125 made 13hp on a real dyno and it was considerably more advanced. So yes the exaggeration started early.

I remember riding one of those and marveling at how well it went compared to my 84 GSX 250. 13 horses ya say? Fuck I'm easily impressed.

**F5 Dave** · 10th February 2016, 16:52

Yeah I think I'd rather have had a GP125 than a Pusey gsx250. What with the remote feeling front end, Suzuki reg/rec failures and tank rust silting up the carbs. Opps, I've given away too much.

Esp as I bought it to get my licence legally, got scared of sitting it on my RD350 (with the slightly home brewed 250 stickers) but was super slow compared. Maybe the gear indicator made up for the lack of power.