Hi,
I got the 555 kit installed as stated in a previous topic. The bike was not starting but it now runs well. It got more performance from the new pistons and the ported and polished and shaved head but it is not as powerfull as I was expecting. Let me explain... I never think that I would got an r1 but I go often to the drag racing track and last year I got 13.49@93mph with yosh exhaust and k&n pod filters with 150 main jets. I got yesterday 13.26@99mph. Its faster but not by that much, I was expecting at least in the 12's.
My question is: what do you guys are running for jets in the carbs with that kit, maybe I am running to lean or to rich even if the plugs looks great. I have 155 mains, stock pilot jets, 3 1/2 out mixture screw, needle one notch higher than stock (no more popping in the exhaust when I let off the throttle)
thanks for help
Gab
what rpm you crossing the line at? if you want to run it as a drag bike you have to have it geared so your almost at 10k or so. my bike will be at the track something it summer and ill let you know what i run with my 14/45 gearing. but you can make a hell of a change just doing gears and nothing else. for example an stock geared bike will be faster off the line then a bike running a 17 front sprocket and my bike with a 14 is just nuts and pulls like a mule all the way to 10k and that right around 100mph
Hi,
I'm not sure at what rpm exactly I pass the line but it is like 8k or something around it. My problem is not the gearing, I got one tooth lower in front so 15t. I am sure there is something wrong somewhere. The place I would think of is the carb as I stated in the first post.
I know that it would be faster with lower gearing but I don't want to ride on the highway at 7.5k, I am already at 6k and that's when I'm going smooth.
I would very like to have the carb settings of somebody who already installed those pistons please.
thanks a lot
gab
Are you running stock cams? If so, you are losing a lot of potential.
I ran 145 mains. 150's were too big. Tried 155 and it ran like crap. Leaner will produce more power.
The 555 I built several years ago...along with the 79mm pistons, I had a Megacycle cams (w/ heavier springs), full Yosh, K&N lunchbox air filter, ignition advancer, and a few other minor mods. Pulled strong to 13K, and wanted more.
hey dgyver; how do you go abouts building one of these motors? :p
Really nice to read from someone who already installed that kit! I don<t have the bigger cams because its not cheap but if you say that there is a noticable difference I'd maybe buy a set... does anybody knows the part number for gs500 camshaft because I think that their catalog does not include gs500 anymore?
I have 150 mains at house, I will try them before going to the drag strip on next friday. Thats for now. I will order 145 this weekend.
On the bike I have:
-Wiseco 79mm forged pistons
- Shaved ported and polished head
- DIY ignition advancer
- One step colder plugs (will try the irridium normal heat I bought)
- 15t front sprocket
- 2 K&N pod filter (right on the carbs)
- Full yosh pipe
- Probably other things I forgot...
If you guy have anyother performance improvement ideas I could put on the bike besides the cams, your welcome.
Thanks a lot
gab
Quote from: psyber_0ptix on April 15, 2009, 01:31:40 PM
hey dgyver; how do you go abouts building one of these motors? :p
The original Wiseco/V&H 79mm pistons are not available anymore. I still have (1) 79mm piston. But I read something about someone talking about being able to have some made. 78mm for the GPZ are stock items for Wiseco. Larger pistons can be used but the sleeves need to be swapped... like the 569cc 80mm piston motor I have sitting on my bench waiting to be put back together, only needs rings.
Cams can be obtained through Megacycle for under $300. Most every mod needed to be done has been done by Gabordi. There are some other small mods, like necked valves, grinding welded back on the exhaust header, sanding the carbs boots to fit the intake port better.
Changing to mechanical slide carbs are also a big improvement, especially for drag racing. Keihin CR Specials are the ones to have. (I have a set for the 569 motor). They can be a touchy for the street though, as compaired to CV carbs. At least increasing to 36mm CV carbs is a good idea.
Hey dgyver, I've looked at the megacycle cam catalog and would you recommend the .380 or the .417 cams? The valve springs are only 35$, I would buy them too!
Thanks
Just buy a bike (http://gstwins.com/gsboard/index.php?topic=47336.0) with the cams and carbs already done right. ;)
Not a single flat spot in the powerband.
BTW, the GS will never be a drag bike. You can make the engine quicker, but you need a course that involves corners in order to hang with the big bikes.
Quote from: gabordi on April 16, 2009, 08:03:58 AM
Hey dgyver, I've looked at the megacycle cam catalog and would you recommend the .380 or the .417 cams? The valve springs are only 35$, I would buy them too!
Thanks
.380
What are you running for fuel, and what are you allowed?
Don't really understand your question but there is no rule of what size of jet you should use, you gotta try it and see the difference.
Ok, I got to the track on past friday and managed to get a 13.08@100mph... Thanks dgyver for telling me that I was running too rich (I've put 150 mains). I don't think I will go lower because the plugs are borderline white to brown. I'll try to put the c-clip on the needle at the original groove.
I will buy soon the cams but got some questions about it and did not find the answer. Do I put the new cams with old camshaft cap with bearing included in it? What should I do? It looks that I am gonna have to put the old used ones. For shim under bucket, how does it work? I was thinking that mor lift was only pushing the valve further. And finally, why do you suggest .380 when you've put .417 in your engines?
Thanks a lot and I'll keep you informed of my new time records
gab