my words with NAMURA!

[blasty98]

dear Namura,
i recently rebuilt my 1998 Yamaha Blaster with one of your pistons. I went through the break in procedures, and the ring alliment pin broke off and destroyed my head and piston. Just to let you know ill never buy fom your company again. First i baught one from you and my skirt shattered. now this? something seems wrong. Your products now costing me 200 $ for a rebuild with a better company than yours. thanks..

I:I

 

[88' blaster]

wiseco pro-lite FTW. soory to hear about that but you get what you pay for

 

[blasty98]

thats what im switching too bro. no doubt about it

 

[lowkhalbalr]

wiseco pro-lite FTW. soory to hear about that but you get what you pay for

i second that. ive put i prolite or prostock in everything ive ever owned, never one time been disappointed. i run a prolite in my blaster now and it kicks ass.I:I

 

[blasty98]

i used to run wiesco when i first got the blaster but i didnt know how to jet so i was running stock jets with all these mods and i keptr blowing her up. but thanks to blasterforum i got on track and jetted my carb lol. just now i gotta rebuild again cause of stupid cast pistons....

 

[hudack]

um i am sorry to say but there are plenty of people runing them pistions without any problems from what i have read they are just like the stock pistion sorry to say but you are doing something wrong cast or foraged a pistion skirt does not just shatter what was the pistion to wall clerance on it when the skirt shattered if you have no idea then il bet that it was off and that was not the pistions fault.
i would sugest sending it to someone else to have it bored and honed because wherever you sent it last time might have screwed up the clearance.

learn from your mistakes like i said a pistion skirt doesnt just shatter you need to figure out why it did before you waste your money again.

 

[bagds101]

if i could find v forces website then i would send a letter to them as well.

 

[revin-it02]

namura pistons are not to bad

they are actually the only pistons that are coated with a graphite film on the skirts to help with dry lubrication (something weisco doesnt do)

i actually just finished my thesis for tribology (the study of friction) on piston skirt and ring friction... namura actually has the best design because their skirts are coated, weisco can cause scuffing whenever a film of oil can not be generated from fluid starvation

 

[York Racing]

Why V-Force? Namura is an independent company aren't they?

 

[blasty98]

namura pistons are not to bad

they are actually the only pistons that are coated with a graphite film on the skirts to help with dry lubrication (something weisco doesnt do)

i actually just finished my thesis for tribology (the study of friction) on piston skirt and ring friction... namura actually has the best design because their skirts are coated, weisco can cause scuffing whenever a film of oil can not be generated from fluid starvation

awsome...........

 

[QuadZ250]

I have a Namura Performance Piston in my blaster and I love it! performance is awesome and so far it's held up well! I'd say you have more problems than the piston! just my .002! actually the cast pistons are Hypereutectic cast pistons and if your not using boost or large amounts of nitrous they last longer and hold up better than forged! I've ran many Mustangs with hyper pistons on a 150 shot and never had a problem! It's all in the tuning!

 

[DUALSTROKE]

Wiseco FTW!!!!!!! namura = crap

 

[UncagedShadow]

the whole reasoning behind forged pistons, at least in the car world, is for forced induction, or super high compression applications, 99% of manufacturer vehicles come with hyper eutectic pistons and will drive the life of the vehicle with those pistons. Same goes for the atv world, stock pistons are hyper eutectic pistons come stock most of the time in most machines. Ever hear of some blasters running 5,6, or 7 years on stock piston? It all comes down to how tuned is your bike. Granted cars i.e. 4 strokes are alot more forgiving because of the dedicated lube system ad most are liquid cooled, but it all goes back to tuning.

 

[UncagedShadow]

something other than "my piston was cast and blew up my motor" was the case here.

 

[blasty98]

actually this is my oppinion. and its not gonna change. WIESCO!!!!

 

[bagds101]

i would write v force a letter cause their design flaw with reed screws falling out.

 

[sicivicdude]

MotoTassinari.com | Superior Airpower

Or their phone number: Phone: (603) 298-6646

A ring alignment pin can slip out of any piston and skirts can break off of any piston as well.

The skirt breaking MAY have been a casting flaw or maybe it was improper cylinder to piston clearance... The pin falling out MAY have been a manufacturer defect or perhaps the pin was pushed to the side inadvertantly during cylinder installation by an improperly installed (but subsequently correcte and properly installed) ring.

I can only put my opinion. I think wiseco pistons will take more abuse and give you less trouble while they're doing it (especially at the end of their life). Wiseco's are what I've got in my engines...

 

[UncagedShadow]

sorry dude, i wasnt tryin to biotch at you or anything. I to am a wiesco fan. I run wiesco in all my atv's and bikes. I was simply stating, dont just blame the piston and pop a new one in there. Find out if it could be caused by some other reason and if a problem is found, fix it so this will no reoccur.

 

[Blaner]

i had my last wiseco eat its alignement pins, they didnt fall out but wore down. HOWEVER my clearance was too tight. There are very few BAD companies nowadays, but there is PLENTY PLENTY of bad installations, i did two in a row - my fault - not wiseco's or Yamaha's (the 1st replacement)

with that said, faulty parts are still a reality...

 

[PikledBeats]

I hate to say it, but I would have to agree that this is a improper clearance/user error. One piston, yes, could be a manufacturer error, but two. Something is wrong with clearance, installation, etc. I have never ran namura pistons as I am a wiseco man myself, but the emphasis put on cast vs forged for non-big block blaster motors is overrated IMO. I am all for learning and doing your own work but after reading would suggest you have someone else (professional) redo your top-end.

Regarding the Vf2's, I remember reading the original post and again have to cite user error. Not properly lokctiting the reed bolts, although the VF3's have gone to screwless design. I can almost guarantee that if you call them they will state the same.

I hate to be the bearer of bad news or pessimistic, but to all, user error is 98% more common than manufacturer error. I'd place money on this.