Just picked up a blaster..

CheapBlaster

New Member

Oct 17, 2014

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• Oct 17, 2014

• #1

so guys i just picked up my first blaster and first thing i do i tear the engine completely down because it blew up.. well its got a +4 stroker crank in it and i have no clie if the cases have been trenched or the head milled so should i keep the crank in it cause it was supposably running before or should i trade the crank for a stock one? the skirt of the last piston was ripped off. i have a brand new stock bore piston and im getting a vitos +4 timing advance key and a high compression gasket kit in the mail. i also have boyesen reeds and a fmf fatty already on the bike. any help would be appreciated thanks

 

Herpderplol

BRRAAAAAAAAAPP

Aug 22, 2012

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Dickinson, ND

• Oct 18, 2014

• #2

it wouldnt run with a +4 and cases not trenched.

with extended crank you dont want to change the timing

stock bore piston wont work

you will need new crank bearings

 

tbrooks

Active Member

Sep 24, 2013

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NC mtns

• Oct 18, 2014

• #3

^^^^ Herp is right on. Wht do you think its a +4, you normally can't trust what people tell you about what your buying, mainly because most do not know what they're talking about. Timing advance and high compression gaskets aren't needed unless you have more mods. With a broken skirt you will probably need at least a hone and probably a rebore. The cases should be split and cleaned of all debris and new bearings and seals installed. Any idea why the skirt broke? Should have done a leaktest before tearing the engine down

 

CheapBlaster

New Member

Oct 17, 2014

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• Oct 18, 2014

• #4

I believe it tore off because of the crank the guy said it blew up ad high rpms and when I split the cases there was a slight chip on the case like the piston traveled down too far then broke. I replaced the side case and I am trying to trade it for a stock crank. Other mods like what to use high compression and timing advance?

 

CheapBlaster

New Member

Oct 17, 2014

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• Oct 18, 2014

• #5

New crank bearings are in the mail too.

 

jus_me

Active Member

Aug 8, 2012

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N.Y

• Oct 18, 2014

• #6

Was there a spacer plate? If not and head wasnt re cut, than the piston would smash into the head. Most likely it was a stock crank. Can you post a pic of the crank?

 

Blaaster

Moderator

Staff member

Technician

Jul 18, 2011

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eastern australia

• Oct 18, 2014

• #7

Before you think about fitting the new piston into the existing cylinder, have it measured for wear.

My feelings are that the piston failed because of excessive wear and it was piston slap that caused it to drop a skirt.

Post up some pics please.

 

CheapBlaster

New Member

Oct 17, 2014

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• Oct 19, 2014

• #8

 

Blaaster

Moderator

Staff member

Technician

Jul 18, 2011

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eastern australia

• Oct 19, 2014

• #9

Have the cylinder measured for ovality.

 

Awk08

Administrator

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Technician

Jan 30, 2009

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• Oct 19, 2014

• #10

the cases must be trenched to fit a +4 crank, if you're sure the cases aren't trenched, then thats not a +4 crank