I have a few questions about a spacer plate on a 330, to make it a 350.

[Narly R]

Ok well for a long time my bike hasnt had any top end power, and now my crank bearings,(im pretty shure) are shot, medal went every where. I was thinking with a 330, with a 350 crank, will have a differnt kinda power that a 350, cause its no bigger bore, its just a longer crank wich means not as much snap right? and will a longer crank like that put more pressure on anything to wear faster? Does anyone have a bike like this and does it have good power? Would I be better off making it back to a 330? I dont want to go threw this agin, but want as much power as I can get outa this thing! Coulda the waring bearings caused it to not want to turn on the top end, which caused it to bog, and it only did it from 3rd onn up.


:mad:

[ShowTime]

I have an 86 with ESR 330 kit. I dont know why anyone would need a faster bike. I dont know that much about the 350. Mine is a spacer plate 330 with esr head, race dome, 40.5 carb, esr reed block, esr 5 centermount pipe and silencer, and is by far the fastest bike I have ever owned. I can laugh at Banshees all day long.:)

[AndrewRRR]

Mine is a 330 topend with a 4mm stroker crank, which makes it a 350. With a stroker crank you tend to get more bottom and mid power while still keeping your top end. The longer stroke means the piston will have more time being pushed down by the power stroke (= more power). Yes the bike will be quite a bit faster if you do it right. I may go to a 8mm stroker this winter if money permits. Keep in mind if you go bigger than 4mm you'll need to trench the cases.
It shouldn't be any harder on the crank bearings than your 330 as long as everything is balanced and blueprinted (this holds true for whatever topend you go with). I'd recommend going with the 87-89 length rod, it won't be at angles as sharp as the 86 rod which puts less stress on everything. I'd also recommend welding the counterbalancer (like they always do on banshees) if you are planning on having a lot of power. I spun mine on the stroker crank resulting in a crank that was 8 thousandths off true.
You will have plenty of power provided it has a good porting job. I usually don't have any problems except for alcohol banshees (and they can't hang with me on the trails!)
As for your bogging problem, that sounds like more of a jetting or ignition issue. If crank bearings are dragging enough to slow you down in higher gears they'll last about 100 feet before they turn into molten crank nuggets.

[Narly R]

Thanks man, will a port and polish job give me that much more power diff.? when you say go to a 8mm crank, I wonyt have to have more spacing will I? I better have a LOT more power. So it would be better to keep the 350 then a 330? I have a LRD bb pipe and 39 pwk carb and carbon reeds, this thing should RIP and it dont, but well try to do stuff right and see if there is a differance, I know for a fact my jetting was to rich...:ermm:

[AndrewRRR]

Porting is what will make or break a motor. Especially when you get into big bores, you have a lot of porting and port-matching to do, including cutting on the cases, mathing lower transfer ports, etc. When you spend $2000 on a big motor, you simply MUST spend the extra $400-$600 to get a really good port job on it, and be specific. Some people I'd recommend are Ripp's Powersports (PM me for their number, they are local), K&T or Packard in Utah (also pretty good), and ESR in cali.
If you do a 8mill stroker you need to trench the case and properly space the topend (usually involving welding cuz you don't want to bolt things together like building blocks).
A 4mm stroker will be fine for a 350 and you should have enough power to keep up with anybody unless you plan on drag racing only. If you get into really big stroker motors things get custom and very spendy. I can show you a 520R that runs on alcohol and nitromethane and has a custom frame but it's not something you are going to take on a trail or jump!
A 39mm carb and big bore pipe should work fine with a 350. If you just have reeds you would probably benefit from an aftermarket reed cage like a V-force or Rad Valve. i have a LRD-ported Rad Valve for sale if you want to PM me. I could let you try mine if you want to meet up sometime in the next couple months if i'm going riding. It's still a 350 for now although I really need a longer swingarm.
Jetting is crucial, it will make a bike fall on it's face on the top end if it's rich.

[Narly R]

Thanks for the info man! I think Ill stick with a 7mm crank, so i dont have to do all that, so a port and polish job is what i need? Seems involved and expenside, and I dont think another 500 sounds too good right now...:( Im interested in ur LRD Rad vaule! Um do you have masn or yahoo? Where do you live in oregon, I like about 30 miles west of Roseburg. Who know maybe it already has a port/polish job...?:ermm:

[AndrewRRR]

Originally posted by Narly R
Thanks for the info man! I think Ill stick with a 7mm crank, so i dont have to do all that, so a port and polish job is what i need? Seems involved and expenside, and I dont think another 500 sounds too good right now...:( Im interested in ur LRD Rad vaule! Um do you have masn or yahoo? Where do you live in oregon, I like about 30 miles west of Roseburg. Who know maybe it already has a port/polish job...?:ermm:

Most big bore motors come with some basic porting if you buy through an engine builder. Who did you get your big bore from? Usually 250R porting is between $200 and $400 depending on how far you want to go (mild to wild). It will make the biggest impact on power at this point as it lets the engine breathe internally.
I don't have MSN or Yahoo, but my AOL IM address is SpooledEclipse or Oregon350r. You can email me at SpooledEclipse@aol.com or PM me here if you want. I'm in Corvallis during the school year and Newberg other times.

[wilkin250r]

Narly, did you ever think about sending your motor to a professional? It's often pricy, but they can get your motor running at peak performance. I'd say that a 310 done by a true professional would outrun a 350 done by a shade-tree mechanic (of course, there may be exceptions to this)

I'm sure for $500 you can have your engine running like a top!

Do you see alot of vibration with your motor?

[lil400exman]

Originally posted by wilkin250r
Narly, did you ever think about sending your motor to a professional? It's often pricy, but they can get your motor running at peak performance. I'd say that a 310 done by a true professional would outrun a 350 done by a shade-tree mechanic (of course, there may be exceptions to this)

I'm sure for $500 you can have your engine running like a top!

Do you see alot of vibration with your motor?

I dunno narly a well running 350r should keep ur pants brown almost all of the time with the power they have soemthing not right and a port job helps so much its mind boggling lol i got a 275r with a good port and that thing runs liek a raped ape man! so a 350r would be ungodly fast man so u really have a problem try jetting a bit more lean and a hotter plug with a port and u should be sreaming man........;)

[Narly R]

Ok well.... Its a Niks motor, I bought it from a local guy who works on these engines. i cant really afford taking it to a a place like LRD (thats who Id send it too) but I will get it all back together, and see what happends, and go from there, there is a machanic at UPPracing thats suppose to be REALLY good, so its cheaper that LRD, there is Portland right? I could take the engine to them sometime, or give them a call or somethin.


$500 to get someone to look at it, 10 for parts and inspection....:(

[AndrewRRR]

Originally posted by Narly R
Ok well.... Its a Niks motor, I bought it from a local guy who works on these engines. i cant really afford taking it to a a place like LRD (thats who Id send it too) but I will get it all back together, and see what happends, and go from there, there is a machanic at UPPracing thats suppose to be REALLY good, so its cheaper that LRD, there is Portland right? I could take the engine to them sometime, or give them a call or somethin.


$500 to get someone to look at it, 10 for parts and inspection....:(

Don't take it to LRD if you want to ride dunes. My motor was ported by them and i wasn't satisfied so I took it to another place. Let me know if you get up to this neck of the woods (portland area) and I'll take you out to see him. I'd say either him, Packard, or K&T if you wanna go fast.

[Narly R]

well if I get max power outa my engine for mx, it would be fine for me at the dunes, Im not a dragger. Ill try to get a hold of ya, I hope to make a couple trips to Albany Supercross, witrh the next couple months, so Ill get ahold of ya then. are you firmilar with BTR, or something racing I fore got egzacly what their name is, but its somethin like that, i talked to them at a corvallis race, they have a dyno and stuff, I might take my bike to them...:ermm: what would be a good place to send my engine to that maily sets them up for mx?



Thanks man!:)

[AndrewRRR]

Originally posted by Narly R
well if I get max power outa my engine for mx, it would be fine for me at the dunes, Im not a dragger. Ill try to get a hold of ya, I hope to make a couple trips to Albany Supercross, witrh the next couple months, so Ill get ahold of ya then. are you firmilar with BTR, or something racing I fore got egzacly what their name is, but its somethin like that, i talked to them at a corvallis race, they have a dyno and stuff, I might take my bike to them...:ermm: what would be a good place to send my engine to that maily sets them up for mx?



Thanks man!:)

Probably the best local builder for a MX motor would be LRD. They are here in Tualatin (near portland) about 15 mins from my house. They build 330/350's and know how to set them up. They have a dyno too.
If you want to send it out, then Sparks and Duncan (paul turner) make some good 265's but I'm not sure if they know how to build big bores and stroker 250r's.

[Narly R]

Ok thanks man, Il get it back together and then maybe send it to LRD if I am having any problems.;) Thank you for all your help!:)