Wiseco high comp piston questions. 1981 GS850G.

[Rijko]

if you are only doing the Wiseco's and no cams etc - stock springs should be okay.
Still available at low cost.

http://www.partzilla.com/parts/search/Suzuki/Motorcycle/1981/GS850G/CAM+SHAFT-VALVE/parts.html

[SpecialK]

Dang...can you pleas send me that link?!?!?! Seriously!!!

I was just able to order it https://www.amazon.com/Wiseco-Suz-Gs...s=gs750+wiseco

even shipped to canada!

[Rijko]

i just asked SVS powersports about the GS1000 Wiseco 1085 pistons.
(https://www.amazon.com/Wiseco-SUZUKI...gs1000+wiseco&)

If that's a complete set of 4, i am ordering too !

[SpecialK]

i just asked SVS powersports about the GS1000 Wiseco 1085 pistons.
(https://www.amazon.com/Wiseco-SUZUKI...gs1000+wiseco&)

If that's a complete set of 4, i am ordering too !

I can't comment on that one but I am skeptical because he the item weight is 0.7 pounds (11 ounces) whereas the 844cc kit is 2.3lbs

[Rijko]

I can't comment on that one but I am skeptical because he the item weight is 0.7 pounds (11 ounces) whereas the 844cc kit is 2.3lbs

pic on Amazon is of just 1 piston, vs 4 pistons on the GS750 kit pic.
You are probably right.
Price of 4 GS750 pistons is amazing, hope i get lucky too

[Colt45]

I plan on doing cams this fall. 600 bucks for cams plus springs are a little to much for my budget right now. I just want to put upgraded springs in now so I can throw throw the cams in and go. And not have to mess around when I want to put them in. I found a set of 500. Ape springs on eBay for 750 850 and 1000 for 80 bucks but do I need new retainers and clips? And will the valve be strong enough to withstand a 500 spring pressure?

[Rijko]

SVS Power sports is VERY quick to respond,
the GS1000 ad is for one piston only

[TeamDar]

I was just able to order it https://www.amazon.com/Wiseco-Suz-Gs...s=gs750+wiseco

even shipped to canada!

I hope it works for you....that link looks like the part number for one piston/rings/wrist pin. K844 is the part number for the whole big bore kit.

[SpecialK]

I hope it works for you....that link looks like the part number for one piston/rings/wrist pin. K844 is the part number for the whole big bore kit.

Ya good point, I contacted the seller telling them to cancel the order if it's only one piston.

[Colt45]

New problem now guys. got it all together with new pistons and valve springs, nut now I think im gonna neew to upgrade the starter. and suggestions? do they make performance starters? and where can I get one?

[Chuck78]

I would think that you have a weak battery and possibly a starter that is on its way out. There is a problem that some of the bigger bikes experience with the starter clutch, which is remedied by an electrical modification to be able to crank the starter before switching the ignition kill switch is on. Is this what you were experiencing? The symptom of that would be that the engine tries to fire before the starter has it up to cranking speed, and it makes a loud thud or whacking sound, as I believe the engine is kicking backwards if I recall.

Slight chance you could have your cam timing wrong, which could possibly generate substantially more compression than what you are supposed to have (as well as other side effects with running characteristics and powerband shifting to other areas) and also put you very near piston to valve collision distance

[Chuck78]

You might want to just try upgrading a battery if you are cranking, but just not strongly. I would NOT recommend a Shorai lithium iron phosphate battery, however! If you are going something other than a standard high end upgrade high capacity AGM or gel cell lead acid battery (DO NOT buy a standard vented lead acid battery - buy AGM or gel cell if sticking with lead acid), i.e. lithium, I would upgrade your regulator rectifier to a Polaris #4012941 (Shindengen SH775) so that you could then run a lithium battery, and then by the absolute highest capacity lithium battery that you can fit in your GS battery box, and I would highly recommend Antigravity Batteries if you are going with lithium iron phosphate cells (LiFePO4). You cannot charge these on a regular charger, and you cannot let the voltage drop below 9 volts, but they are bulletproof compared to the others on the market and ultralight. Also, your regulator rectifier and charging system needs to be in Tip-Top shape and not vintage design, must be a modern unit and good stator. They are ultralight but also ultra expensive! I am running an Antigravity 4-cell high-powered battery since I do not use it for a starter motor, Kickstart only. It weighs less than 1 lb and is the size of a deck of cards! You would want the big capacity 8 cell or 12 cell version, the biggest that would fit in your battery box, if you are not having other issues as I outlined above, this would be the solution.

[Colt45]

After jumping it with jump box and letting it run last night it has no more cranking issue. But I do have a high idle issue. I did tear tear it all down, installed the new pistons, lapped the valves and put in new valve springs. Fired it up and touched the throttle and the idle sticks at 3500-5000. I figured okay I bumped the idle screw or pinched the throttle cable, throttle cable is good and free. I turn the idle screw down and it stalls, turn it back up and it sky rockets after you hit the throttle. I tried carb clean/ starting fluid, and water to find a vacuum leak and nothing changed. Could I have the intake cam off a tooth causing this? It took me close to two hours trying to get it right or what I think it right. I used my clymer repair manual for a guide but it doesn't say anything other than lining the exhaust cam /mark one pointing 1-2mm below where the valve cover gasket goes then to have mark two on the exhaust and mark three on the intake cam 20 link pins apart with it being at top dead center. Scares me that I might be off a tooth.

[exdirtbiker]

Please don't look for vacuum leaks with water.... if you find a big leak, you may bend / break stuff you thought was unbreakable.

[Drybear]

Hi,
I'm curious about how this modification worked out in the end?
I also plan for wiseco pistons in a 850 cylinder and wonder if there will be any improvement?

Regards,