Honda-SOHC

SOHC.co.uk Forums => CB350/400 => Topic started by: billdn on August 09, 2017, 12:38:59 PM

Title: Fitting rocker box cover
Post by: billdn on August 09, 2017, 12:38:59 PM: After running out of funds back to the reassembly and yet again something isn't right! the rocker box doesn't sit flush on top of the head. I've checked it's not warped and all appears OK. the head is tightened down but the cover seems to be fouling on something or won't sit directly on. it's difficult to see what but when the crank is rotated it gives the impression that the cam lobes are sitting too high. i've checked and the cam is fully engaged in the head journals. is it just what happens until you tighten the rocker box down, i suspect it isn't. i've tried placing rocker box on a spare head without a cam in and it fits flush perfectly. any thoughts? :-\
Title: Re: Fitting rocker box cover
Post by: hairygit on August 09, 2017, 01:13:44 PM: Are all the tappets slacked off? Also are the holes for the locating dowels spotlessly clean? Are the dowels themselves clean and not covered in rust?
Title: Re: Fitting rocker box cover
Post by: Gixxer-18 on August 09, 2017, 01:22:24 PM: Also check the tachometer drive is meshing with the cam gear...
Title: Re: Fitting rocker box cover
Post by: mike the bike on August 09, 2017, 02:23:21 PM: It's never going to sit right because there's always one cam lobe trying to open a valve so don't worry too much about it.
Things to note, however.
* Make sure all the dowels are there. (can't remember how many, may be 0)
* Go gently with it, you don't want to damage the tacho drive on the cam. A small amount of paranoia is ok.

As Hairy suggests, slacken off all the tappets. They'll need adjusting properly anyway.
Title: Re: Fitting rocker box cover
Post by: billdn on August 09, 2017, 06:29:39 PM: Thanks all. There are 2 dowels to the rear and they're new and holes are clean. I'll look out for taco drive meshing fully too. It's great to feel able to ask apparently dumb questions and get good advice thanks guys. ;)
Title: Re: Fitting rocker box cover
Post by: mike the bike on August 09, 2017, 08:36:38 PM: No such thing as a dumb question; only dumb answers.
Title: Re: Fitting rocker box cover
Post by: hairygit on August 09, 2017, 09:21:55 PM: Quote from: mike the bike on August 09, 2017, 08:36:38 PM
No such thing as a dumb question; only dumb answers.
Dumb questions are the ones you DON'T ask, then break something expensive/impossible to get, or use the bike in a downright dangerous condition. We all started somewhere, and back in those days there was no Google, Wikipedia or forums like this, coz there was no internet!

Sent from my X6pro using Tapatalk
Title: Re: Fitting rocker box cover
Post by: Johnwebley on August 09, 2017, 09:28:54 PM: be careful fitting the topcover,

use rubber bands under the tappet so they don't bend a valve or two
Title: Re: Fitting rocker box cover
Post by: mike the bike on August 09, 2017, 09:50:20 PM: We're discussing 400s here John, keep your shabby rubber band tricks for 500s.
Title: Re: Fitting rocker box cover
Post by: Johnwebley on August 09, 2017, 09:56:09 PM: Quote from: mike the bike on August 09, 2017, 09:50:20 PM
We're discussing 400s here John, keep your shabby rubber band tricks for 500s.

sorry Mike,but the rubber bands are the only thing that makes them go !!!