I've got an '83 Gl1100 that I've refurbished the past year front/back and top/bottom thanks to this forum(DynaBeads-right on). I'm the original owner and have stored the bike for the past 20 yrs w/o riding much at all. I refurbished the carbs last year.
I bought the bike in Kansas, but now I ride in Colorado from 5000' to 11000' altitudes. The bike rides great under most conditions except at altitudes above ~8000' to 9000' when climbing steeper grades.
Start the incline in 5th at good speed, but into the incline with throttle full open it starts to lose power and I have to down-shift and run the RPMs up to maintain speed. This is not the case at 5000'-6000'.
Is this to be expected from a carb system or do I need to modify the carbs in some way for these altitudes?
Appreciate any advice, it has always been good from you folks.
Riding at altitude
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virgilmobile
- Posts: 9102
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Previously owned
78 GL1000
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83 GL1100 I
83 GL1100 standard
84 GL 1200 I
Re: Riding at altitude
Yes your problem is jetting for high altitude.
If you spend more time above 9000' than 5000' rejet the carbs.
If its just an trip to the peak omce in a while,live with it.
Unfortunatlly the 1100/1200 did not have altitude compensation systems.
It always required new jets.I did this for my wing when i lived in the Springs,it ran a touch rich but took the pass fine.
If you spend more time above 9000' than 5000' rejet the carbs.
If its just an trip to the peak omce in a while,live with it.
Unfortunatlly the 1100/1200 did not have altitude compensation systems.
It always required new jets.I did this for my wing when i lived in the Springs,it ran a touch rich but took the pass fine.
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redial
- Posts: 2130
- Joined: Mon Jan 03, 2011 1:17 am
- Location: Labrador, Queensland, Australia
- Motorcycle: 1997 GL1500 Spectre Red Aspencade
Re: Riding at altitude
The mountains of Colorado are certainly one of my favourite places in the US. I am wondering whether you are asking the engine to do too much? If you are labouring it, in any gear, then you should be changing down, anyway. The engine should be kept in the "happy zone" where it is working well, and not having to labour in any particular gear.
You should not be expecting to climb Mt Everest in 5th gear, no matter how much of a run up you have
. But by ensuring that you keep the revs of the engine in the happy zone, I bet it would climb Mt Everest.
I hope I am not teaching you how to suck eggs, but the gears are there for us all to use, all the time - not just to get started.
You should not be expecting to climb Mt Everest in 5th gear, no matter how much of a run up you have
. But by ensuring that you keep the revs of the engine in the happy zone, I bet it would climb Mt Everest.I hope I am not teaching you how to suck eggs, but the gears are there for us all to use, all the time - not just to get started.
Len in Kapunda
The world is not going to finish today, as it is already tomorrow in Australia and New Zealand, and other islands of foreign nations such as Guam and Samoa.
The world is not going to finish today, as it is already tomorrow in Australia and New Zealand, and other islands of foreign nations such as Guam and Samoa.
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Grabcon
- Posts: 3
- Joined: Wed May 22, 2013 10:58 am
- Location: Castle Rock, Colorado
- Motorcycle: 1991 St1100
1976 CB750F
1974 CB750K
1978 CB550K
Re: Riding at altitude
I have similar issues with my 1991 ST1100 which has lived in Colorado all of it's life. This is just a matter of fact riding at altitude.
With carbureted motors on the average you will lose 5% of your power for every 1000 foot rise in elevation. Meaning in Denver you have already lost 20% as compared to sea level. Jetting will help but if you don’t ride at this elevation all the time then that is an issue as well.
Gears are a wonderful thing at 10,000 feet.
With carbureted motors on the average you will lose 5% of your power for every 1000 foot rise in elevation. Meaning in Denver you have already lost 20% as compared to sea level. Jetting will help but if you don’t ride at this elevation all the time then that is an issue as well.
Gears are a wonderful thing at 10,000 feet.