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Discussion Starter #1
At least as far as I need to go at this point. No Big bore kit at this time. I will use custom pistons in the stock bores if it works out, if not then onto bigger things. I will post pictures in my album as progress continues under sub album "Project RWHP". More photos from todays break down in there now.

The tear down was simple and painless with the only difficult time being removal of the cam gear retention bolt - actually rounded it before it broke loose but its cheap at 4.38.

Next step is to remove the remainder of the motor from the frame and cart the chassis off to the powder coaters to look at color chips. Still undecided on cams and carbs. JCW

 

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If I may make a suggestion regarding cam's I would opt for a pair of 790cc cams...advancing the exhaust cam one tooth from the default stock position. This will accomplish 2 things, 1 it will make the bike pull harder on top, and 2 advancing the exhaust cam will make the torque curve look like the 865 motor.

Furthermore I would hope that you would seriously consider the 42mm Mikuni HSR's from bonneville performance. There has been discussion about these in the past that would seem to suggest that they do not work. I can assure you that they do work when properly setup.

I can honestly say I got very nearly as much gain in adding the hsr's as I did when I added the 904 kit.


Your bike is so nice man....have fun wrenching and keep us posted on your decision's and results.
 

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Discussion Starter #6
On 2006-11-19 15:40, SCCTrim wrote:
If I may make a suggestion regarding cam's I would opt for a pair of 790cc cams...advancing the exhaust cam one tooth from the default stock position. This will accomplish 2 things, 1 it will make the bike pull harder on top, and 2 advancing the exhaust cam will make the torque curve look like the 865 motor.

Furthermore I would hope that you would seriously consider the 42mm Mikuni HSR's from bonneville performance. There has been discussion about these in the past that would seem to suggest that they do not work. I can assure you that they do work when properly setup.

I can honestly say I got very nearly as much gain in adding the hsr's as I did when I added the 904 kit.


Your bike is so nice man....have fun wrenching and keep us posted on your decision's and results.
Thanks - I've been reading your threads on motor mods with great interest. I had been looking at the FCR 39's but now I'm not sure.
 

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I cannot offer comment on the FCR's as I have no experience with them. Since removing/disabling the accel pumps from the Mikuni's...( they should not be enabled )...the bike run's great.

The acceleration down low is crisp, and midrange and topend are very strong with no sign's of being over-carb'd.

You could go HERE to ask more question's about the carb kits. Bill from Bonneville Performance is a regular there, as well as Lee..( wiseco developed their 904 kit with him )...these guy's are very knowledgable about the carb's and could answer question's for you.

It will be intresting to see your result's with the stock bore and higher compression pistons. Looking forward to your progress with this project.
 

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I'm very interested too in the higher compression stock pistons, the only thing that I wonder/worry about is how to seat new rings on used nikasil cylinders. If yours works I'll be very interested, but I'm not brave enough to be the guinea pig.

I'm thinking about the wiseco kit myself.
 

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Discussion Starter #9
On 2006-11-19 19:43, sweatmachine wrote:
I'm very interested too in the higher compression stock pistons, the only thing that I wonder/worry about is how to seat new rings on used nikasil cylinders. If yours works I'll be very interested, but I'm not brave enough to be the guinea pig.

I'm thinking about the wiseco kit myself.
I will try to get some pics up after I clean up the jugs and pistons. I was very surprised at the lack of any visible signs of wear. If you over look the carbon on top and just examine the pistons skirts and told me they were Brand New - I would have no reason to doubt it. The jugs are the same - the cross hatch honing inside looks like it was just done. I was nervous about dropping new pistons and rings in the old bore but after seeing how well they appear to have held up, I much more confident. But not crazy, I'm still going to have the bores completely checked before going forward.

I have reservations about the weisco kit - just the use of iron liners pressed in. Something so 1960'ish about that. On the other hand weisco is known for quality stuff. I have much more confidence in going 80,000 miles on nikasil liners. I see no quality or reliability problems with iron liners, just the longevity. I'm hung up on that nikasil lining, its use on long lasting motorcycle engines is widespread. I also don't see much gain for me in getting 39 cc for for all that cash - I think most power gain is in the increased compression rather than the 39cc. If I do go big bore it will be the 994 set-up. JCW
 

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I agree with you about the minimal gain from displacement increase, and that most of the gain is from compression increase, but the 994 is just too oversquare for my liking, and it seems too thin on the cam-chain side of the bores. Also, I think B-Customs is very, very, very overpriced on all their stuff...

I hope the higher compression stock bore pistons work, but what I do like about iron liners is that you can hone them and drop in new pistons and rings, but refreshing nikasil (while you may not need to) is a lot more $$$.

You have balls my friend. I like balls. (what movie is that from? I can't remember).
 

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Agreed on machines post regarding BC...and also about the 994 kit. There are quite a few post's regarding kit's and the like at the link I posted above.

For what it's worth, jojje is a frequent visitor there as well.


A good pool of info to draw from over there.
 

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Discussion Starter #12
I not inclined to any big bore set-up at this point - and it's extremely unlikely I will add any cc's. Even a simple one over on the custom pistons and bore the stock jugs then replating with Nikasil is far cheaper than even the weisco kit. About $100.00 per cylinder to re-nikasil them according to some pricing I've done. JCW
 

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Discussion Starter #13
On 2006-11-20 05:23, Thrux-ton-up wrote:
I not inclined to any big bore set-up at this point - and it's extremely unlikely I will add any cc's. Even a simple one over on the custom pistons and bore the stock jugs then replating with Nikasil is far cheaper than even the weisco kit. About $100.00 per cylinder to re-nikasil them according to some pricing I've done.

Thanks for the site SCCTrim. Machine - all the overpriced parts at BC and BP and others is what prompted my task of custom pistons and over size valves and getting it done myself. JCW
 

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John, I have a nikasil question:

Say you check your bores and they do in fact need to be rehoned and replated/nikasiled. Do you have to replate, and then measure the bores before you order the pistons, or is the process accurate so that you can specify thickness of the plating (in microns, or some other unit of measure)?
 

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Discussion Starter #18
On 2006-11-20 09:15, sweatmachine wrote:
John, I have a nikasil question:

Say you check your bores and they do in fact need to be rehoned and replated/nikasiled. Do you have to replate, and then measure the bores before you order the pistons, or is the process accurate so that you can specify thickness of the plating (in microns, or some other unit of measure)?
Jeff - not sure on the answer - the barrell will be measured at three points top, bottom and middle and if in spec then I'll drop the new pistons and rings in. If out of spec I turn it all over to the machinest to get it bored, plated, and pistons ordered.
 
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