Engine painting advice

sye

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I've been asking a lot of questions lately and getting good answers, so here's another. :p

The engine paint is in very poor condition and someone has tried to patch it up previously using eggshell gloss black and a stirrup pump. I've removed all of it and am now left with bare patches here and there. Surprisingly, the cylinder appears to be in reasonable nick, it's the underneath and sides that have suffered the most. I want to do as good a job as possible without removing the engine. I can remove left and right covers and oil supply line, starter motor, exhaust header and water pump, which should give me good access to the front for painting. I do have a couple of questions please?

Is it possible to remove the front engine mount bolts one at a time to paint around the bushes?
The water hoses have the clamp-on clips, how do I slacken them off for removal and do I then need to replace them with jubilee clips or can they be reused somehow?
Apart from the obvious gaskets and washers, is there anything else I should replace whilst I'm there?
The header nuts are a pile of rust and I'm afraid to put a socket anywhere near them. Any advice welcome?
Anything else you can think of that may help me would be greatly appreciated.

Thanks. :thumb2
 
I've been asking a lot of questions lately and getting good answers, so here's another. :p

The engine paint is in very poor condition and someone has tried to patch it up previously using eggshell gloss black and a stirrup pump. I've removed all of it and am now left with bare patches here and there. Surprisingly, the cylinder appears to be in reasonable nick, it's the underneath and sides that have suffered the most. I want to do as good a job as possible without removing the engine. I can remove left and right covers and oil supply line, starter motor, exhaust header and water pump, which should give me good access to the front for painting. I do have a couple of questions please?

Is it possible to remove the front engine mount bolts one at a time to paint around the bushes?
The water hoses have the clamp-on clips, how do I slacken them off for removal and do I then need to replace them with jubilee clips or can they be reused somehow?
Apart from the obvious gaskets and washers, is there anything else I should replace whilst I'm there?
The header nuts are a pile of rust and I'm afraid to put a socket anywhere near them. Any advice welcome?
Anything else you can think of that may help me would be greatly appreciated.

Thanks. :thumb2

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Never repainted an engine (though i sure have a few that would benefit from it.

Re clamps; i think there is a tool you can use, but you can remove them without. When i do, i replace them with stainless jubilees.

Re exhaust studs, if you can get them out i'd replace with stainless allen bolts, with some copperslip on the thread to prevent issues in the future.

Also check the condition of the two main rubber water hoses; if incorrectly routed they can burn on the exhaust. You can still get them new if needed.

There is a small metal water jointing pipe under the rad. It is exposed and mine seem to take a battering. If system is drained then take opportunity to repaint if.needed.
 
The key is always good prep, so take your time cleanig & degreasing the areas of concern. The BMW issue is usually the level of corrosion hiding beneath what looks like sound paint on the surface

Then, & I only do these jobs very occasionally to make a bike look easier on the eye, I have always used PJ1 heatproof paint in a rattle can. This needs to be sprayed in a warm, dry environment, with cases at room temp. The front parlour is ideal.

Seems to work well for me ........... https://pj1.com/i-19004780-pj1-fast-black-high-temperature-paint-1500f-flat-black.html

GFJ covers the other issues, although I wouldn't use copperslip & allen bolts when screwing into alloy; I have known guys strip the threads in the head. So I would just replace the studs with stainless & maybe copperslip lightly the new stainless nuts. Make sure you get good quality SS.
 
Just a quick update OP - I gather PJ1 have stopped selling their silver case paint, so just provide a variety of black finishes. Seems they have passed the baton to Simoniz, who do both silver case paint for bikes & cars as well as VHT exhaust manifold paint.
 
Thanks all for the excellent advice. As a result I'm going to be ready to do the prep over this weekend. I have bought a few things to aid with the job following a helpful conversation with John and advice from GFJ and squibb above.
VHT SP148 primer engine enamel
VHT SP139 satin black engine enamel
Hose clip pliers Clic® Compatible
IRWIN 5 Pce EXPANSION Damaged/Rounded Bolt Grip Nut Remover Set 8-19mm (for manifold studs)

Will let you know how it turns out.:thumb2
 

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and the elastoplasts for the cut/blistered fingers lol

Ha, not yet but I have my first problem. I thought it would be the exhaust studs but they came out fine after soaking overnight, heating and using the Irwin bolt grip sockets. The right hand starter motor bolt however is another matter and I've snapped the bugger about 5mm from the head. This leaves me with the starter stuck fast on the remaining thread and no obvious way of removing it. Cup of tea and severe looking at called for :blast
 
Ha, not yet but I have my first problem. I thought it would be the exhaust studs but they came out fine after soaking overnight, heating and using the Irwin bolt grip sockets. The right hand starter motor bolt however is another matter and I've snapped the bugger about 5mm from the head. This leaves me with the starter stuck fast on the remaining thread and no obvious way of removing it. Cup of tea and severe looking at called for :blast

If you have the one bolt out and the head snapped off the other one you should be able to remove the starter motor then you may be able to get access to the threaded portion of the snapped bolt and hopefully be able to get it out

A couple of pictures below of the engine block fixing positions for the starter motor and the starter motor mounts - may help picture things for you

24vm893.jpg


zxlnnk.jpg
 
Thanks for the pictures John, the problem is that the right hand stud has seized to the mounting point. I can't heat it up too much otherwise I will melt the wiring in the motor. I can't get a puller on as there's no room for the legs, so I'm resigned to spraying release fluid on for a few days and then try again. Here's hoping...
 
So, I now have the starter motor and stud out. The problem appears to be that there is a wire guide attached to the right hand bolt. This stops the head seating against the starter motor mount, leaving a 2mm gap where water gets in. It then does it's thing and corrodes to such an extent that it fills the mounting hole and becomes stuck fast. The left over stud came out easily with just two nuts against one another and no force was needed.

The starter motor has now been wire brushed, rubbed down with 400 grit, primed and painted. The mess will take a little longer...:thumb2
 

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So, I now have the starter motor and stud out. The problem appears to be that there is a wire guide attached to the right hand bolt. This stops the head seating against the starter motor mount, leaving a 2mm gap where water gets in. It then does it's thing and corrodes to such an extent that it fills the mounting hole and becomes stuck fast. The left over stud came out easily with just two nuts against one another and no force was needed.

The starter motor has now been wire brushed, rubbed down with 400 grit, primed and painted. The mess will take a little longer...:thumb2

The wire guide should have a washer on both sides of it to prevent that happening so make sure to fit them when you re-assemble
 
The wire guide should have a washer on both sides of it to prevent that happening so make sure to fit them when you re-assemble

Good to know thanks.There wasn't a washer there when I removed it, just a flange head bolt.
 
Almost there now. Engine primed and painted then dried using a fan heater on high to bake it a little. New bolts and cleaned up the spacers too. Just waiting for exhaust header gasket and it can go back together. Didn't take the side covers off in the end, just painted over the old bolts and replaced them with stainless. It's not as shiny as it looks in the pictures, I think that must be the flash effect. Quite chuffed really. :aidan
 

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Almost there now. Engine primed and painted then dried using a fan heater on high to bake it a little. New bolts and cleaned up the spacers too. Just waiting for exhaust header gasket and it can go back together. Didn't take the side covers off in the end, just painted over the old bolts and replaced them with stainless. It's not as shiny as it looks in the pictures, I think that must be the flash effect. Quite chuffed really. :aidan


Looks great - top job !!
 


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