Getting more from a 79 850G (Shaftie)

[BSinCO13]

I have been reading up on these great forums but haven't seen much on the performance side for us shafties. I live in the Rockies of SW Colorado and the bike really loses power going up the mountains. My girlfriend likes to ride along and the power really suffers with two people. What all can I do and what should I look out for while introducing more power to the old bike? Thanks for any help.

[Billyboy]

Push that thingy by your left foot down one click. If that doesn't improve power, try twisting the grippy thing on the end of the right handlebar.

[Commodus]

Hum, I would expect a GS850 to have plenty of power, regardless of mountains and passengers and whatnot.

First, verify that the machine is running properly - that it has good compression, the carbs are carbing, spark plugs sparking, etc.

There certainly are things you can do for more power, but if you just want it to handle normal riding, the stock bike should be more than adequate (says the rider of a GT550 with no problems with mountains or passengers \\/ ).

[Deesel]

1000 engines fit nicely in an 850 frame! That cured my underpowered troubles for a couple months anyway. My 850 was not really underpowered that bad, but it didnt run like my new (to me) 1000 engine does.

[txironhead]

My '85 Shadow VT700C shaftie never gave me a problem in the hill country (big hills, we don't really have mountains here in Texas, just hills and a lot of dust...) and from what I understand inline 4's have considerably more power that a v-twin of the same size. I would definitely check to make sure the bike is running right. From what I've gathered here (and I've already filled one notebook with notes and tips) these bikes can "seem" like they're running great, when in reality they're not in top shape and a lot more can be achieved with proper tuning, jetting, etc. A compression check and spark plug reading can probably tell you a lot.

All that being said, I agree with the downshifting post, especially when riding 2-up.

[bwringer]

IIRC, the later CV carb models have less trouble with higher elevations. Anyone know if this is true?

I've been to Mount Mitchell (6,684 feet) a couple of times on my '83 GS850, and never noticed any lack of performance at higher elevations. Of course, you might be dealing with much higher elevations than that.

[BSinCO13]

Yeah most of the time it doesn't seem to die out until about 9,000 feat or so. I have changed plugs and did notice the old ones seemed to be a little black indicating running rich. I have noticed that the intake boots are worn and hard could that be affecting it that much? I guess this winter I'll just have to get it to nice original running condition and check it out from there. The previous owner did mention something about this being a problem with CV carbs.

[SqDancerLynn1]

Years ago I had a CB750K up around 8-10k ft Tioga Pass. Was lucky to keep it going 25mph If it is always going to be at higher alt ? bump the compression up. Remove the head & have a .025 cut done. degree the cams, check valve to piston clearance-should be fine.

[bwringer]

Yeah most of the time it doesn't seem to die out until about 9,000 feat or so. I have changed plugs and did notice the old ones seemed to be a little black indicating running rich. I have noticed that the intake boots are worn and hard could that be affecting it that much? I guess this winter I'll just have to get it to nice original running condition and check it out from there. The previous owner did mention something about this being a problem with CV carbs.

Your 1979 GS850 has slide carbs. CV carbs were found on the 1980 and later models.

But again, I'm not entirely sure that the CVs actually do handle high elevations any better. Just a theory. Someone who doesn't live in Indiana will have to step in with an actual informed opinion...

[jimcor]

Someone who doesn't live in Indiana will have to step in with an actual informed opinion...

Yes, riding the roads near Franklin and the "Pinnacle of Indiana" have caused many riders to rejet, change plugs to a higher heat range and, of course, breathe supplemental oxygen. Brutal weather conditions are to be expected.

http://www.waynet.org/waynet/spotlight/2004/040908-highpoint.htm

[Billyboy]

Yes, riding the roads near Franklin and the "Pinnacle of Indiana" have caused many riders to rejet, change plugs to a higher heat range and, of course, breathe supplemental oxygen. Brutal weather conditions are to be expected.

http://www.waynet.org/waynet/spotlig...-highpoint.htm

HA!........................