What do you guys think of this kit?

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i am wanting the same kit, a few people have said they were great, the je pistons are good, not sure what type of cams they use
 
Looks like a great kit for the money. I don't think i'd go straight to the +2mm bore though, I'd say start with the 1.5, that way you have enough cylinder wall left for one more rebuild instead of shafting yourself and having to re-sleeve when it's time for another rebuild.
 
I don't think i'd go straight to the +2mm bore though, I'd say start with the 1.5, that way you have enough cylinder wall left for one more rebuild instead of shafting yourself and having to re-sleeve when it's time for another rebuild.
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During a rebuild, all the cylinder should need is a good deglaze and hone, no substantial amount of material will come off from that.

The only need for a re-bore is if the cylinder is out-of-round, and thats not gonna happen unless it was bored out-of-round to begin with.
 
Well my cylinder to begin with has some good deep scratches honing wont get ride of. My local machine shop said they will bore it our to the size of my piston I get for 60 bucks.

Would there be a power difference from the 1.5mm vs the 2mm over bore, anything noticeable?

I think this kit is the best bang for your buck if your looking for some more ponies out of your bike...It would be sweet if anyone that has this product tell a little more about it before i go ahead with a order
 
I doubt you will notice any power increase from a 2mm overbore, the power will come from the cam and high-comp piston. I'd just go 1.5 that way you can bore it 2.0 if you grenade your engine and gouge the cylinder walls
 
Well my cylinder to begin with has some good deep scratches honing wont get ride of. My local machine shop said they will bore it our to the size of my piston I get for 60 bucks.
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Deep scratches? From what exactly?

Shouldnt be any unless you broke a ring, or got some crazy piston-slap going on.

Are you able to take any pics?
 
There are a couple reasons why I went with a 366cc piston. More you bore the more compression you will get out of that cylinder. The highest compression pump gas piston is 10.5:1. I also didn't want to f with putting a bigger sleeve in or anything like that. I wanted to get the most out of this engine with out having to stroke it or do any of that. Going from a stock bore to 85mm will give you about a 1.5 hp gain. Both by uping the compression and gaining that 18cc's which isn't much both ways but if you're going to try and get everything out of her. ..
Most of the time I've found that you can just hone a cylinder out and re ring it and it's perfectly fine, if it wasn't over heated or oil pump went out or something of that nature. .. Also LA sleeve sells a 87mm over bore piston and sleeve big bore kit that works good, also CWR sells I believe a 89mm over bore. But the cases will have to be bored out as well.
Anyway, this is a good kit. This piston looks actually to be a 12:1 and race gas might need to be required. I wonder if they uses gaskets to make it a 10.75:1 compression piston. I asked them directly and they wouldn't tell me other then it's a good piston.
The cam they use is a megacycle 252x1 .450 race cam. Which if the piston has that much compression it will work great together. Nice they include all the gaskets for this.
 
[quote:xcypk3vs]I don't think i'd go straight to the +2mm bore though, I'd say start with the 1.5, that way you have enough cylinder wall left for one more rebuild instead of shafting yourself and having to re-sleeve when it's time for another rebuild.
Click to expand...

During a rebuild, all the cylinder should need is a good deglaze and hone, no substantial amount of material will come off from that.

The only need for a re-bore is if the cylinder is out-of-round, and thats not gonna happen unless it was bored out-of-round to begin with.

[/quote:xcypk3vs]


That's interesting, because both of my quads i've rebuilt (my recon and my warrior) were both out of round and needed a rebore. The recon's was so bad that I was getting piston slap from it. Pretty sure they didn't some that way from the factory...
 
That's interesting, because both of my quads i've rebuilt (my recon and my warrior) were both out of round and needed a rebore. The recon's was so bad that I was getting piston slap from it. Pretty sure they didn't some that way from the factory...
Click to expand...

OOR from the factory has been known to happen, those industrial bore machines dont always have their bearings changed when they should. Production Control Engineers use a fairly loose manufacturing tolerance in some cases, as to reduce machining cost (i.e. the longest they can get bearings to last). Sometimes the jigs (depending on the design) can get a little sloppy over time as well.

Wear from typical rings will not cause a typical cylinder sleeve to go OOR, that includes the sleeves commonly used in Yamahas. The rings will always give up material 1st in the majority of applications.

I bet if I pulled the jug off one of my Raptors right now, it'd be sloppier than I personally like to see, even though it basically works OK.
 
[quote:njxe44w6]

During a rebuild, all the cylinder should need is a good deglaze and hone, no substantial amount of material will come off from that.

The only need for a re-bore is if the cylinder is out-of-round, and thats not gonna happen unless it was bored out-of-round to begin with.
Click to expand...




That's interesting, because both of my quads i've rebuilt (my recon and my warrior) were both out of round and needed a rebore. The recon's was so bad that I was getting piston slap from it. Pretty sure they didn't some that way from the factory...[/quote:njxe44w6]

I just did my last year (my warrior is a 98) and the cross hatch pattern was still in the sleeve. The cylinder was in great shape. I thought for sure it would have been out of round and all that other ****. I mean I beat the **** out of it. I held it WOT in 6th for like miles rev'd up I know to valve float, I'm suprised I didn't bust the rod. Sounds like the rod bearing is starting to let go now though.
I've seen many engines like this where they haven't been overheated or anything but just needed a freshen up. Yes the piston to cylinder clearance may have been just a little wider the stock but still with in spec.
Like griff said the big factor is how good of a job did they do boring it. This plays a big factor in how the cylinder holds up and even starts out as, how well the engine is maintained is a another one.
I guess in the end it's all up to the dude rebuilding the engine.. . Good to get the facts out there and relise what can happen and how much more it will cost you for a new sleeve and to get one press in and bored.
 
Out of topic but were can I find one of those 87mm big bore sleeve and piston kit i've looked into La sleeve web site but I didn't found anything.

thanks

Max
 
I'm not sure what pistons they offer, it would be a good idea to call Greg and ask him.
This kit would have some power.
12:1 compression- FST uses 11:1, so you may have to use racing gas if you don't use a large cam.
89mm bore - FST uses 87mm
9.5mm more stroke - FST uses 10.5mm.
460cc to the 446cc.
 
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