Engine swap out

[lmigore]

Hi Guys,

I'm looking into swapping out the engine in my cb400. Would have a bit of a clue, but was wondering if anyone had any more info on how to go about it. Is there a "Dummy guide to swapping out an engine" in existance. Fancy giving it a shot as have been quoted €200 for the job. Any advice would be appreciated.

Thanks
Gar

[amorti]

Why?

It is a home job if you're good with tools and have a wide selection of sockets. You'd be best off with a rattle gun for the engine mount bolts and front sprocket but you'll get away with a big breaker bar. Other than that, not much to it. Remove cables and wires, number HT leads!!, airbox and carbs off, exhaust off, drain oil and water, remove hoses, swap engines, reconnect to the same plugs and fittings, fill oil, bleed water.

Of course it's not "that" easy, but it's not that much harder either.

That was on a CB-1, I got it out in about 4 hours, and back in not much more. That's an open-bottomed frame, so I just put the engine on a crate and slid it under. I imagine it may be more tricky on a cradle frame. Looking at a picture it looks like the engine might be a bugger to get out. Deffo don't try it on your own.

Another top tip is to do all the above, remove the body panels, lay the bike on its side and drop the engine out, then lay the new engine in in the same way. Might be best on a cradle frame.

Frankly £200 is a very good price though. I'd be tempted to save myself the bother. It's going to take anyone on his own 6 hours, even if he knows what he's doing, that makes that a great price to my eye.

http://i74.photobucket.com/albums/i264/ ... _A0052.jpg

http://i74.photobucket.com/albums/i264/ ... _A0053.jpg

Why can't this forum just bloody resize images if it's going to be so pernickety about their size?? Lots of other forums do it.

[lmigore]

Hi Amorti,

Thanks for getting back to me. Have spent a fortune on trying to rectify a voltage problem over the last 18 months. Bought a crashed bike for parts and fancy sorting it out once and for all. Mechanic reckons it's an engine problem. Just weighing up my options at the moment.

I'll chance getting the donor engine out of the crashed frame and see how that goes. Depending on that I may take on the other. Worried about getting it out of the cradle too without making bits of anything. I wouldn't have any experience at this, sure I'll learn the hard way.

Cool photos of your handy work, fella.

Wish me the best.

Gar

[amorti]

I really don't see how the engine can give you faulty electrics. My suggestions: get a regulator from a bigger bike, R6 ones are supposed to be OK on the VFR so would have to fit the SF, double-earth it with one going straight to the battery and then see how you go. It's what I did (except I got really lucky and found a s/h aftermarket regulator on ebay)

http://i74.photobucket.com/albums/i264/ ... thmod3.jpg
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Your images may only be up to 480 pixels high.
That's really beginning to get on my wick. Why oh why not just resize the pics to required size using the forum engine?

[superfourben]

Your images may only be up to 480 pixels high.[/b][/color]
That's really beginning to get on my wick. Why oh why not just resize the pics to required size using the forum engine?

The forum is still under development, try some tests in the forum testing section or get in touch with Paul (username CRM) as I doubt he will be reading everything that goes in other sections such as this one and he might be able to sort something out in the future :)

[lmigore]

Hi Amorti,

I hear what you're saying. The only reason I think it's the engine is that the engine housing covering the flywheel/coils etc has always had a pretty bad battle scar on it (prone to leaking a bit of oil.) We checked out the electrics initially reckoning that was the fault. Found nothing. 3 reg/Recs and a rake of batteries later and still no joy. We took a look at and replaced the flywheel and the coils as both were slightly damaged from the possible fall that damaged the engine cover. A couple of months later took a look at the flywheel again only to see that it was scowered again in the time we'd replaced it. So I reckon there's a bit of play in there somewhere causing the problem.

Anyhow have wrecked bike with other engine outputting 14 Volts at high revs and my limp cb400 only getting 12.5 Volts at equivalent revs.....

The BIG QUESTION .....

Could I re-route the coil output from the donor bike to my own, i.e. using the alternator/coils from the donor to charge the battery on my sick bike... proving out that the engine is at fault ? Could I damage either bike in the process? I've made up cables and would like to know if I could cable them up before starting both bikes !!! Could this work. Anyone out there have any reason why I shouldn't attempt this ?

Amorti, just want to rule this out before going looking for other reg/recs. Grateful for your help.

Gar

[amorti]

i have a spare clutch cover with alternator in A1 nick. it's off a cb1 so looks a little different but will fit. It's gunmetal grey, off a late model CB1. I changed an alternator and had to change it out again not long after as i forget to remove the copper shards off the magnet. Anyway, not knowing what was wrong I went into squirrel mode and got another alternator in case. Don't have the bike any more, so don't much need it. Depends how hard it's been down - if it's enough to bend the crankshaft end and put the flywheel slightly out of true rotation, you're probably best to have the new engine in (though, I do actually have a spare engine with a flywheel on too, but I heard they're a pig / more trouble than it's worth to get off.) You'd know by looking as, well, it'd have coil-shaped interface marks. I doubt that though, you'd have more trouble than you're getting!!

Careful cleaning that magnet btw, it has very sharp edges. If you are getting lower v's than expected, could point to one out of three coils being burnt out. If that's right, usually not long til one of the others goes. A broken regulator usually causes higher v's than expected, usually leading to a dead battery.

Also have a very good lookat the plug between alternator and loom, three yellow wires into a small block. It's not up to the job, melts or corrodes, causing high resistance, and takes out the coils. Go on, ask how I know You can sort it by chopping back, fitting fat spade connectors using solder on the joints and protect using heatshrink. Belt and braces is the way unless you like fixing thngs again later.

12.5 is enough to about keep the bike running, but is unlikely to charge it, so it will always run down in the end, at least if you like using the lights and starter. If you want, you can make an offer on the cover and alternator I have. Much less trouble (if it's that) than a whole engine swap. You'll know just to look at the old one whether it's burnt out, it literally "burns" out, and you'll see black sections that were meant to be copper coloured. Just needs a gasket and you'll be good to go.

[eddie v twin]

as you take it apart take loads of photo's stage by stage, so when you go put it back together you have a guide. Also try too keep parts with there relevant bolts and fastners in containers


Eddie

[amorti]

Take the side case off and see if you see something like this...