SuzukiSavage.com - 0.5 mm Over-sized Piston

T Mack 1 - FSO

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0.5 mm Over-sized Piston - Rejet??
07/30/07 at 10:05:10

Does anyone have experience with the 0.5 mm oversized pistons???

Do I need to rejet the carb??? I've done the white space mod (took two tries to get washers that would fit into the depression in the slide). I have the brass plug out and ready for when the engine is back together. I'm still in the process of cleaning the internal parts. I guess I should post of pict of the insides for everyone to see, not much there.

Bike is a 2001 and looks to be 100% stock when I picked it up. Other than the engine was in pieces and the piston looked like s--t (Melted and flaking on the trailing side). Bike has 10460 miles.

I'm planning to keep the pipes and air cleaner stock to start with. The exhaust pipe has almost no blueing and the muffler is slightly discolored at the back.

I did the volume calcuations and it's going fm a 652cc to a 659cc displacement. That's just over 1% larger.

I would be grateful for any shared knowledge. A from/to jet size would be good if you've already did the O.S. piston.

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Bugscraper Full Member 2004 No Login Offline I love YaBB 1G - SP1! Posts: 130 Gender:	Re: 0.5 mm Over-sized Piston - Rejet?? Reply #1 - 07/31/07 at 18:16:37 Just curious why you didn't bump it up to 700cc's while you were at it?
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jd06s40 Full Member Offline live to ride Posts: 121 marion ohio Gender:	Re: 0.5 mm Over-sized Piston - Rejet?? Reply #2 - 07/31/07 at 18:30:59 is there a big bore kit with piston,rod,cylinder,etc for the savage/s40 650 available
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LANCER Serious Thumper Alliance Member Offline Savage Beast Performance Parts Posts: 10661 Oklahoma Gender:	Re: 0.5 mm Over-sized Piston - Rejet?? Reply #3 - 07/31/07 at 18:50:07 Pistons available in 95, 96 & 97mm overbore, then just have the cylinder bored at a machine shop, use same rod.
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jd06s40 Full Member Offline live to ride Posts: 121 marion ohio Gender:	Re: 0.5 mm Over-sized Piston - Rejet?? Reply #4 - 07/31/07 at 19:27:35 what would that 97 take the cc to
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klx650sm2002 Serious Thumper Offline The more I learn the less I know. Posts: 2041 Cumbria,England Gender:	Re: 0.5 mm Over-sized Piston - Rejet?? Reply #5 - 08/01/07 at 02:36:02 A 97mm piston would give 694cc. Clive W
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T Mack 1 - FSO

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sold 2001 LS650 for
a 1986 XLH1100

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Re: 0.5 mm Over-sized Piston - Rejet??
Reply #6 - 08/01/07 at 06:36:28

Bugscraper,
Didn't bump up to 700CC this time because I'm from old school where we try to repair things over & over again. In another 20 to 30K miles I'll go one more step up, then after that another , and another.

Hey, here's a idea, why not do like they do to the Honda 50cc's. New jug & head assy's that increases the size of the engine. On those, the case opening has to be machined to fit the bigger sleeve. Can you see a Savage with a 1000cc or even a 1200cc engine......probably would need a safety harness just to hold you on to the bike during accelerations. Wonder how long the tranny could handle it?

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Engineers design things, Technicians make them work.
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30% of being mechanical is confidence/30% is knowing to go slow when needed/30% is looking repeatedly at what you have/10% is dumb luck Wink

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Savage_Rob Serious Thumper Alliance Member Offline Mechanically Inclined Amateur Posts: 6972 Texas (Dallas area) Gender:	Re: 0.5 mm Over-sized Piston - Rejet?? Reply #7 - 08/01/07 at 09:45:44 I think I'd be concerned about the effect of increasing displacement too much without modifying the counterbalancer. Doesn't that seem logical?
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srinath

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Re: 0.5 mm Over-sized Piston - Rejet??
Reply #8 - 08/01/07 at 11:02:54

LANCER wrote on 12/31/69 at 16:00:07:

Pistons available in 95, 96 & 97mm overbore, then just have the cylinder bored at a machine shop, use same rod.

Yes ... however that is only 1/2 true ... those are DR650 pistons ... Grin

and oh yea, they'd fit and work and be super cool, however they are much lighter and stronger and have these tiny skirts and I believe they have piston pins that sit too close to the rings. Wonder if they would lower the compression,
Also a lot of like 400CC atv's have huge pistons and they also are super light and have pins that sit 1/2 way in the bores.
Cool.
Srinath.

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T Mack 1 - FSO Serious Thumper Alliance Member Offline sold 2001 LS650 for a 1986 XLH1100 Posts: 2919 Emmaus,Pa Gender:	Re: 0.5 mm Over-sized Piston - Rejet?? Reply #9 - 08/02/07 at 06:37:17 So, now that my what if made you think, let's get back to the thread. Rejet the Card for the factory 0.5 mm O.S. pistion (94.5mm)??????????????
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vroom1776 Serious Thumper Offline Posts: 2110 Gender:	Re: 0.5 mm Over-sized Piston - Rejet?? Reply #10 - 08/02/07 at 10:46:27 start rich and work your way down.
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T Mack 1 - FSO

Serious Thumper
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sold 2001 LS650 for
a 1986 XLH1100

Posts: 2919
Emmaus,Pa
Gender: male

Re: 0.5 mm Over-sized Piston - Rejet??
Reply #11 - 08/17/07 at 13:59:55

So, contiuing from the gas mileage thread:

First: Thanks go out to Lancer for selling me jets.

Today, was off (have to use up vacation days or lose them).

Took out the factory 145 jet (2001). (had to take battery housing off, means seat too). Put in the 150. Then, what's that noise,......thunder.....turn on radio and hear severe T-Storm warning and tornado warning for neighboring county 20 miles away. Tornado's in PA.......Da_mn.....

Well, start bike & play with air screw, was 1 1/2 turn to lean roughness, 1 turn to rich roughness. Could explain the carbon on sides of spark plug ceramic. Turn down 1/2 turn. Turn off bike, go eat lunch. Come out and start bike, hey need one click of choke, might be a sign that was too rich before (carbon on spark plug).

Sun is out and roads dry. Roll out of garage and see dark clouds coming. Quick trip around the big block (about 1 1/2 miles). Runs a bit better.

Home again, come in to check forun, see Lancers suggestion to put in the 155 first, D-amn, off comes seat & battery housing. 155 in, ten minutes, wow, getting better at this. Roll out of garage, more dark clouds, but will try. Get 1/4 mile and it starts raining, but.....no bogging down, ...hmmm. Get home and here I am waiting for the roads to dry again. Want to get to the highway for some 55 MPH driving.

Lancer, again, thanks for the help......

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Engineers design things, Technicians make them work.
---
30% of being mechanical is confidence/30% is knowing to go slow when needed/30% is looking repeatedly at what you have/10% is dumb luck Wink

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LANCER Serious Thumper Alliance Member Offline Savage Beast Performance Parts Posts: 10661 Oklahoma Gender:	Re: 0.5 mm Over-sized Piston - Rejet?? Reply #12 - 08/17/07 at 15:18:39 Happy to do anything I can.
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T Mack 1 - FSO Serious Thumper Alliance Member Offline sold 2001 LS650 for a 1986 XLH1100 Posts: 2919 Emmaus,Pa Gender:	Re: 0.5 mm Over-sized Piston - Rejet?? Reply #13 - 08/17/07 at 18:07:12 Did a 15 mile run. Bike runs good, smoother and more power/torque. No bogging down what so ever. When I got home, let engine cool down.....check plug. Looks ok. Yea........will check again in a week or so.
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Savage_Rob

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Re: 0.5 mm Over-sized Piston - Rejet??
Reply #14 - 08/18/07 at 07:25:45

Savage_Rob wrote on 12/31/69 at 16:00:08:

I think I'd be concerned about the effect of increasing displacement too much without modifying the counterbalancer. Doesn't that seem logical?

I didn't see any thoughts on this. I don't know if everyone just thought it was a stupid question or if they were studiously avoiding the topic. I mean, on a multi-cylinder engine it's less of an issue and it's virtually a non-issue as long as opposing cylinders are enlarged at the same time but I'm thinking the counterbalancer is designed with the stock displacement in mind. While it may be that small increases in displacement won't make an appreciable difference, wouldn't it follow that the engine would become less stable the more you alter the displacement?

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