Every carbed bike I've had has done the midrange stumble when cold or a lot of city drivin, just bounce the tach needle of the redline in 2nd and 3rd gear a couple times after its warmed up should fix it. They like to be run hard.
Looking for more power
- Thread starter NAKED_ST
- Start date
well maybe but almost 1/2 second faster and more top speed
rwthomas1
Site Supporter
While I can appreciate the anecdote, it's just that. If there is no data to back it up, how do you quantify the gains? Swapping cams is a fair bit of work, I think I'd like to know what the results will be. To my mind what is needed is a set of custom ground cams with more lift and duration. Probably could get away with a re-grind, and then shim out to compensate for the reduced base circle, but that's a bit of a kludge. RT
As far as I know, there are no aftermarket upgrades to increase hp. Suspension, yes. Windshields, yes (they don't usually increase performance), etc. There is a temp sensor marketed that is supposed to fool the bikes sensor into thinking its a little cooler than it really is thereby richening the mixture, but that has gotten mixed reviews. Aftermarket exhausts are available, but I'm not aware of anyone posting before and after dyno figures for any of those. Bottom line, there simply were not enough of these made for aftermarket speed shops to design and sell accessories that might increase performance. A supercharger/turbocharger? Where are you going to hang it? These are compactly designed bikes with not a lot of room for anything aftermarket.
I semi facetiously suggested to someone else looking for more acceleration to lose some weight. That is probably the only way to make your bike faster. Get out your dremel and start grinding every excess ounce off the bike. Hook up your laptop, download the engine's map from the ICU and tweak it then reinstall it. If your engineering and computer skills are not sufficient for these tasks you might be stuck with a stock naked bike. And that's not a bad thing.
rwthomas1
Site Supporter
You installed early stock cams, yes? I know they are slightly more aggressive, ie, more lift and duration, so more air/fuel in, more exhaust out. How much valve overlap is optimal for an ST? No idea, but I'm pretty sure it could be figured out based on the dozens of other V shaped engines out there. Look for one with a similar bore/stroke ratio, head design, and go from there. Cam design is a very mature subject, any cam grinder could make recommendations and come pretty close. Custom cams would allow a much larger increase in lift/duration as well as whatever overlap is desired. A lot more power could be made, but the emissions would be much higher. That goes with the territory. Custom ground would allow a whole lot more than the small increase from the early Honda cams.
RT
Andrew Shadow
Site Supporter
That is for the ST1300. He has an ST1100.
Right, I kept forgetting he is talking about an 1100. Should have said, if you want more power, get a 1300....
OP
OP
I appreciate that shift joke sir that got me good! i have replaced the plugs and wires but i havent thought about a fuel treatment yet so that will most likely be my next step. I usually use Lucas treatments but i see everyo e is saying to use sea foam! Is there a difference i should know about?Oh. Yes... Right.
Mine too does that sometimes. And it's an easy fix.
See, between five and six thousand RPM... when it does that... the bike is trying to tell you : "maybe you could try shifting gears now".
Just kidding.
Well, I'm also still new to the ST1100 and I am not as knoledgeable as many members on this forum. I've learned a lot since a year, though.
When I bought my ST1100, last year, it hasn't had run much for the last two three years.
So, at first, yeah, the engine was kinda missing an explosion here and there. Every two three second. I looked at my spark plugs and they were all covered by a black layer of carbon deposit. I cleaned them. And... to make a long story short, I burned a few gaz tank with "seafoam" or injector / carburator cleaner in the gas tank. It now really runs smoothly.
Do you have lots of mileage on your ST ?
Thinking, maybe you could check the valves clearance.
OP
OP
I bought the bike as a rebiuld someone had started but didnt have time to put back together. He never got far enought to mess with any major mechanical parts but he had got rid of most of the stock body panels including the gauge cluster. I didnt mind as this was my first road bike and i knew i would be going through some learning pains and having a really nice bike would not be a good idea. So with that i dont know exact mileage but the last recorded millage on the title is 67,548 miles. Any help would be much appreciated!
rwthomas1
Site Supporter
You are missing the point. There is more there, likely a lot more. I don't doubt that your stock cam upgrade made a difference. The question would be how much. With regard to changing to custom, the engine would have to be degree'd with the existing cams, and mapped. The valve protrusion would have to be verified, with modeling clay in the combustion chamber, to see how close the valves come to the pistons now. Then again with the new custom grind. Fly cutting pistons is no big deal, done all the time in the hotrod world. Some intrepid souls have done it by hand, in situ. None of this is particularly difficult, but it is time consuming, and pretty invasive engine-wise. Which is why nobody has bothered with a low-volume, obscure old motorcycle. Say a new set of cams produced a 25hp gain, with a little carb tuning? How many sets of cams would the cam grinder sell? I'm guessing a set of custom cams would be well North of $1K. How many customers would there be? Not many. Maybe none.
RT
Fast riders on slow bikes are much faster than slow riders on fast bikes. Read that twice.
rwthomas1
Site Supporter
Yes, if you want to spend the money (which nobody is going to do on a ST1100) then of course you can get more. That is obvious, captain. So the only realistic option for a performance gain is to install the earlier cams (if you are running with the later cams). It's irrelevant to me to know exactly how much of a gain it is.
It would be nice to see a dyno pull to see what the gain was, that's all. I would consider it at timing belt replacement if the gains were quantifiable. Or I can keep riding and not worry about it.
RT
One could probably have hot cams or webcams come up with a custom grind for the 1100 since it's carbureted. But you'll be messing with the breather box and the exhaust to make it worth your while. It's already high compression, so you may end up not being able to run pump gas if you put a fatter charge in there. If someone actually goes through with all this nonsense, please start a thread for us to follow All of your heartache and bills so that we can live vicariously through all the excitement without any of the pain or expense.
Drop a gear. Bring rpms up in the moment of clutching to match engine speed as you re-engage. Leave all cages in dust. Much cheaper than engine mods and applicable on the road more than the road race, where you would be high in the RPMs and not needing to drop a tooth to find better acceleration. Technique will trump nearly anything you might do to a ST1100 motor without really getting deep into it. There is no significant, easy, bolt-on power for the STs.
Nothing to do with racing. Everything to do with technique. If dropping a tooth doesn't help you make the jump to light speed in a more satisfactory manner, wrap the throttle further. If that's still not doing it for you, it would be cheaper to buy a cbr600f3 with 300 less pounds and almost as much hp compared to the cost of adding 10 measurable hp to your ST.
Nothing to do with racing. Everything to do with technique. If dropping a tooth doesn't help you make the jump to light speed in a more satisfactory manner, wrap the throttle further. If that's still not doing it for you, it would be cheaper to buy a cbr600f3 with 300 less pounds and almost as much hp compared to the cost of adding 10 measurable hp to your ST.
Would be cheaper to drop in a chevy small block
How about half of a small block chevy
stock ST1100s run just fine, actually best, on 87 octane regular gas since they have a rather unimpressive compression ratio of 10.0:1. Since its common for other motorcycles to have CRs in the 12.0 to 13.0 range, I wouldn't characterize the ST1100 engine as high compression. But, we're in agreement that pursuing power gains through engine mods is mostly a waste of time and money that would be better spent on the purchase of a different bike.
ST engines ARE half of a V-8.
Sadlsor
Site Supporter
Wait, wait... hold on there!ST engines ARE half of a V-8.
Let me get my scientific engineering calculator, 'cuz that sounds bogus.
Here, let's see...
8 divided by 2 to get one-half...
Damn!
It says 4!
HE'S ABSOLUTELY RIGHT!
I made the mistake of assuming the 1100s had the same compression as the 13s.