Big bore GS 1000?

[Anonymous]

My '80 GS 1000G has low compression. If I pull the head, both the head and cylinders will get attention.

I've seen the Wiseco overbore kits for 1085 and 1100 cc's. I'm want a reliable, smooth sport touring bike, not a hot rod. What kind of re-jetting would I need with the larger displacement? Would 10.25 to 1 compression ratio be pushing it for pump gas? Would I be better off with just new pistons & rings?

I plan no other mods.

[Einar J Skog]

Hi

You should need no rejetting.

The bigger pistons suck more air and petrol .

When I got from 1000 ccm to 1100 ccm I kept the same dynojet settings that I had before.

Las Autumm----
As a test I took a few runs on a long uphill road..

In 5th gear, I passed a fence at a speed of 80-Km , and then put on max throttle.

Up to another mark along side the road.Where I looked at the speedometer again. 120-KM

Last week I took the same test 4- 5 times again with the 1100 ccm ..

I had 140 Km at the top mark .

So I have got much more torque now ,and where I need it.
In normal driving Rpms.From 3000 Rpm and upwards.
Not only at top Rpms.

I run it on what we have here in Norway (95 octan Lead free.)

[Rico]

"I run it on what we have here in Norway (95 octan Lead free.) "

WOW 95 oct.

Here in Washington state there is only one station I know of that has 93 octane. And when I was in California last week the highest I saw was 91.

How come you "Norge's" get the good stuff?

Rico

[Guy]

95 octane is standard here in Ireland too. I have the 1085cc (73mm) kit in my GS1000 and I agree with Einer: Torque is significantly increased but top end hasn't changed noticably. Probably because it's still breathing through two valves and there's a limit to the amount of gas they'll flow. If you want your bike to pull like a tractor and still be reliable, go for the 1085cc kit. I've heard that the 1100cc (73.5mm) kit leaves too little meat on the liners and can cause problems with overheating and subsequent warpage of the liners. Don't know if there's any truth in this.

[feelergaugephil]

95 Octane! coool! but your paying 783 quid a gallon!!!!

[Guy]

Yes, fuel prices here have gone mad here in recent years. A gallon of 95 unleaded is now about 4.50 euro or 5.85 US. We don't use quids here. We've had the euro for almost four years now as has most of Europe.

[feelergaugephil]

I remember years ago, I used to put 2 pound in my off road Honda C70 and ride all weekend, rain, snow or Sun, I'd be out riding.
2 pound won't get you much juice these days, but I have moved from U.K to USA and paying about $2.2o a gallon which is approx 1pound 15 or so.
I moved before the euro came in.

[Jethro]

Guy Posted: Fri May 20, 2005 6:57 am Post subject:

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Yes, fuel prices here have gone mad here in recent years. A gallon of 95 unleaded is now about 4.50 euro or 5.85 US.

Holy shiznit!!!! 8O 8O 8O

5.85/gal? That is insane, man. It costs you the same to fill your bike as it does to fill my truck here in the states. Rediculous.

[feelergaugephil]

Oh Yeah! When I go back to visit my friends in UK, I always get the smallest rental car, because paying $8 a gallon, YES< YOUR READING CORRECTLY< $8 a gallon, so, we in USA have NOTHING to complain about.
Walmart is pretty cheap here, Walmart bought ASDA, which is a company in U.K and they sell gas (petrol) a little bit cheaper than most.
But paying 17.5% in taxes, the Gov't get most of the profits from petrol and cigs.

[Big T]

I also have the 1085 with stock carbs and exhaust. More torque and 85 RWBHP, according to the dyno.

No rejetting needed. My machinst chamfered the edges of the heads combustion chambers to elimiminate a potential hot spot due to the larger bore.

Hi octane (93) definately required.

I love cracking it open at 4 K and zooming away. I had a chance to do some "parade" laps at PIR a while back. 3rd gear pulls right up to 105 mph, I shut down at about 120 in 4th so I wouldn't scare other riders (and myself) coming into turn 1.

[SqDancerLynn1]

You should be ok with 10.5 You should use an oil cooler because it will produce alot more heat. Heat will make it detonate
WHen I started driving we paid .25 cents a gallon & had price wars