"Topp Racing" Cranks

[clubbook]

The only other thing Paul is have it split and possibly welded.

Would i need to put a new con rod in when doing that mate?

[mickdale]

Sorry Mick my comment was a bit misleading should have probably written it "has been re-trued to improve balance" As nothing has been done to alter the balance! However when "trueing" last time have only been able to get it to the maximum recomended tolerance. So thinking it may be time for a new one?

I think it was caused initially by a couple of minor heat seizes and then one good seize! All bearings seem to be good and are decent quality, all seals replaced etc

Cheers
Paul

thanks for the reply paul
maybe a new big end pin will help the tolerance issue? - would save a few quid
cheers
mick

[shamrockexpress]

I HAVE JUST REMOVED THE CRANK TODAY AND AFTER CHECKING ALIGNMENT DISCOVERED IT WAS RUNNING OUT 0.30mm.
the crank looks in good new condition and little miles on it although the piston had a few minor scuffs!!!!!!!!

SO CAN ANYONE IDENTIFY THIS PISTON AND WHAT CAN I DO TO REPAIR IT??
will this crank always be problematic??
thanx in advance.





the piston is stamped ART inside with 1/2 and is 66.8mm is this a honda or pattern?

[Diablo]

.3mm out of true is over 10 thou " out. Thats very twisted. Where did you measure it mate?
I've found MEC cranks very good value for money but |I've never fitted one in anything fruity without having the pin welded.

[shamrockexpress]

Hi Al, (did you get my e-mail about the HB SPRINT ENGINE STUFF??)

Measured it at the furthest away point from the center end of flywheel taper!!!.3mm run out on the v-blocks,,,, at the web it was .2mm so pretty bad,, i,m quite surprised as it seems a good quality crank with strong conrod and beefy webs and taper but obviously not so good a big end pin fitting!!!!!

[Diablo]

Hi no didn't get it.
Just to confirm my email address is [email protected]

[Danger]

hi ive just bought a mec crank on ebay off scooterclearance for £89 quid new bargain , am i now going to have to spend more money on it having it trued an balanced an as i live in belfast there,s no one here that can do it that i no of anyway, plus what are the costs of having such a job done thanks D

[mickdale]

hi ive just bought a mec crank on ebay off scooterclearance for £89 quid new bargain , am i now going to have to spend more money on it having it trued an balanced an as i live in belfast there,s no one here that can do it that i no of anyway, plus what are the costs of having such a job done thanks D

why do you need it trued?

mec cranks are the best on the market by far for the money - the pins have a much stronger interfereance than the others on the market in the same price range.

if you havent damaged it - there will be no need to "retrue it"

the reason clubooks crank is out is he has repeatadely seized his engine forcing his crank out of true

[Danger]

thats great thanks for that mickdale

[tha83]

hi ive just bought a mec crank on ebay off scooterclearance for £89 quid new bargain , am i now going to have to spend more money on it having it trued an balanced an as i live in belfast there,s no one here that can do it that i no of anyway, plus what are the costs of having such a job done thanks D

I'm certain that there is a competent machinist that works on bikes in your area that can perform things like pin welding and checking for true. It doesn't have to be a scooter builder. Call your local Brit bike tuner and ask them who they use for machine work. It's not rocket surgery.