CB750 Barn find project - First Timer

[Underdog1]

Used the hacksaw method on mine, two cuts. There is advice on here but I can't remember who posted it. With two close cuts removing a thin strip the rest came out easy.

This worked well btw

[Woodside]

caswell uk do a steel blackening chemical im pretty sure.
give them a call

[Woodside]

edit
caswell europe...

www.caswelleurope.co.uk/for-mild-steel/

[Underdog1]

Decided black spokes aren’t worth the bother, I just won’t clean them so they will look black anyway 

Took the frame, wheel rims and hubs, seatpan, a load of rear brake hits, engine mount brackets, wheel brace, fork lowers, steering stem, triple tree, swing arm, battery box and loads of other misc bits to the powder coaters today. He said even though the chrome bits will be a pig he will do it all for £220. Well happy with that, especially as he is 5 minutes down the road from me.

Was looking through the boxes of bits I have and it’s been so long since I stripped the old girl down I don’t recognise half of it, at least I sandwich bagged most of it and vaguely labelled it up.

Looking forward for it to start resembling a motorbike again. Trying to avoid buying an old enduro bike that’s cropped up local as I don’t need one, it will eat up my spare time and cash.. but it would be a right laugh!

[Trigger]

If your powder over chrome, the paint will peel off in time. They need to be de chromed first.

[Underdog1]

If your powder over chrome, the paint will peel off in time. They need to be de chromed first.

yeah thats what he meant when he said the chrome rims are a pig to powder coat as stripping the chrome is difficult, but said he has done it before with good results

[Underdog1]

Have ordered some TT100 tyres and some progressive fork springs from hagon. Basically just need the bits back from the painters and i can get things reassembled.

Had a manual clean out of the carb bowls a while back but need to do a more in depth clean, thinking abut buying a small (2l) ultrasonic cleaner, they have them on amazon for <£40. Also going to up the main jets from 105 to 110 and idle jets from 40 to 42 as the 4 into 1 system going on is basically straight through and im going to be running pod filters (because i never want my bike to run well again).

Anyone got any guides bookmarked on carb cleaning?

Wheres a good place to get the jets from?

EDIT just seen my cruzin image carb rebuild kit came with 110 mains so just need the idles

[Underdog1]

Bits have started arriving

TT100s:


Hagon springs and 20L of vinegar to pickle my fuel tank in:


Unfortunately they've sent me a 3.50 19 front rather than the 4.10 i ordered but the wheels aren't good to go yet anyway, spoke to them this morning and the replacement will be here tomorrow. Have gone mad ordering all the bits i need to finish the bike, yet to be delivered is:

ultrasonic cleaner and carb solution
Short reverse cone for my MAC 4-1 system
Mini tacho
Mini speedo with LED idiot lights
Some different size jets
Vinyl leather stuff and foam to build the seat
New wheel spokes
and a few other misc bits.

I think all i need is a new chain and sprockets, possibly new points (may try and reuse the old ones), new brake hoses (looking to get some braided ones made up that go straight into the caliper - anyone know of any suppliers?) and some carb balancing stuff (not really looked into this yet).

There are plenty of shops in the states that sell cool bits for old bikes, have purchased stuff from 4 into 1 and Dime city in the past. Was hunting everywhere for the speedo and tacho that i wanted, a few crop up on ebay but they are always £30+ postage and you'll probably be stung with import duties etc.

Found this cool website https://modernmotorcyclecompany.eu who sold exactly what i was looking for, decent price cheap postage etc. Might be of use to some of you?

[Underdog1]

Decided to pour 5L of white vinegar into the tank and leave for a few days. Didn't want to use my rebuild petcock with new seals as i don't think the vinegar will do them any good so i used an old one with perished seals that i had to fill full of vaseline.



Tank looks a bit of a state inside but i think its mostly varnish. After a day or 2 im going to give it a good shake with some nuts and bolts, drain/strain and go again.




If i don't make much progress I can step it up a bit by using thinners (although a little worried it will eat the paint if i spill any and i want to keep the aged look to the tank. If that doesn't work then I've spoken to a local rad shop who will clear it out without damaging the paint. They reckon £50-100 depending on condition (rust id imagine).

[Trigger]

That is one bad tank, you will have to used Electrolysis to get that anywhere near clean. Or take it to a pro chemical strippers.

[Underdog1]

That is one bad tank, you will have to used Electrolysis to get that anywhere near clean. Or take it to a pro chemical strippers.

I had a crack at electrolysis ages ago, whilst a little bit bubbled up i think that the layer of varnish stopped it working properly which is why im trying to chemically attack the varnish this time round. If i don't make any headway after a few DIY attempts ill take it to a pro

[Rob62]

Good thread!  Be interesting to see it all coming together...

[Underdog1]

No real progress with the tank after 24 hours. Its removed exposed rust as the filler cap hole just wiped clean



I drained the vinegar out but it was still clear



Decided to throw in some nuts and bolts with a litre or so of vinegar and shake for 10 mins resulting in some varnish chunks being knocked loose. Drained again.



Refilled and will leave it another 48 hours before trying another method.

This is what was knocked out by nuts and bolts





and where the chunks have come away from inside the tank it looks like clean metal which is kind of encouraging, although i feel rust is easier to deal with than old fuel varnish



The powder coater had concerns of the contrast between the gloss and satin black i had chosen so i popped round so he could show me some samples. Decided to go for gloss and matt as the matt he uses isnt as flat as i thought it would be. The bits are ready to be coated now.




Postman came again this morning and dropped off my Chinese special ultrasonic cleaner which im going to use on the carbs. Smaller than i thought (2l) but will fit a striped down carb in one at a time which is all i need really.



Have applied for a dating letter from VJMCC. As i don't need to MOT this bike i can apply for the UK registration as soon as my 55/5 form gets here from the DVLA, even with the bike still in bits.

[Rob62]

Let us know how you get on with the dvla

[Underdog1]

Just got back from a few days away and the old fuel varnish situation hasn’t changed. I left a piece in a capful of thinners too as an experiment but it was still very much in one solid piece with the thinners all evaporated... the powdercoater suggested steaming it out but might need to take it to the radiator shop. Interesting side note - the zinc coated bits and bolts i threw in there s few days ago to shake around for 10 minutes I wiped off with shop towel and left on the side. The vinegar completely removed the zinc coating on them!

Unfortunately whilst all the hits have been painted I wasn’t able to pick them up today, was hoping to have the engine in the frame at least tonight but no cigar.

I have however completed all my paperwork for the DVLA, wasn’t as difficult as first thought as half of t is irrelevant anyway.

Plan is to get the engine in the frame with headstock and swing arm on at a minimum tomorrow depending on how much free time I have. I brought the engine home today, forgot how difficult it is to get in and out of a saloon boot single handed