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CB550 First Build - Hondvarna?

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cinqmars2:

--- Quote from: Bryanj on January 07, 2013, 05:22:38 PM ---Those carbs are the same as fitted to all 500/550 EXCEPT the K3, and whilst they runn richer are far easier to stip/clean/get parts for

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Ace! Thanks Bryan, appreciate the help!

matthewmosse:
In theory I daersay that is correct but in practice I've never found any crud having found it's way down the inlet or exhausts either having installed such engines or stripped them as a precaution, I've never had engine failiure that I'd thought might be attributable to anything entering by this route - I always open problem engines up to take a look and haven't found scored bores or bad piston wear, appart from one engine that had all 4 pistons missing their top rin and all 4 pistons and head scarred badly, since several broken rings were found in the sump and gaskett goo was everywhere I think extreme bodgery were the culprits on that count - the engine went on to do several years commuting given some cheap pistons from another engine and eventually dropping 2 valves - but given it's history I wasn't surprised, it looked like it had been run with all 4 top rings in bits in the engine (worst assembly job ever?)- the piston tops were well pitted - I've no idea what could have caused such a failiure. I prefer to test run an engine and get a really good idea as to internal condition by looking at how it preforms then fix accordingly if needed.
My personal approach would be to stick a hoover over each port to suck any crud out and turn the engine over by hand a few times then try runing as is. Meaning no disrespect but having messed up bits myself and seen as many by others in my earlyer years I'm very aware that inexpirienced engine strip and rebuilds can cost a lot of money and effort and destoy good components. Conversly the 500 and 550 engines are tough cookies and can go for many many miles with basic servicing - 180 000 on my 500/4 sidecar outfit with no engine work up to that milage. Only work it will need for the original motor is new gaskett set fitting and new rings in all probability, the gearbox was the issue, jumping out of 2nd and 1st. I may get a more expirienced mehanic to check valves and crank bearings whilst it is appart but going by visual inspection they are probably ok. Of the 10 or so engines I have either in bits or as runners from bikes I've got as projects, the engines that are factory builds rather than owner rebuilds are the ones that run best- that is if my crude diagnosis method is correct, all unspoilt looking phillips head screws and bolts being right and undoing with that cirtain satisfying noise and feel = factory build, owner rebuilds more typycally feature Allen head bolts that so often foul rocker covers etc - the list goes on - either way I prefer the old addage of if it ain't broke - don't fix it. I've had US inport engines that at first leaked like sieves, smoked like the proverbial and sounded nasty that have come good after 500 miles use.

cinqmars2:
Thanks for getting back to me guys!

Hmm ok, well Engine 01 has a few parts missing, like Oddjob noticed, the tach, the points are also missing, there are numerous replacement bolts around the engine, ranging from hex to philips in varying states. This engine has definitely been tampered with so it's safe to say that it's not still the factory assembly. As neither I, nor the previous owner, have had this running, I can't say what condition it is in to perform any running diagnostics. I think the best approach would be to strip it right down, gives me a chance to clean it and get it painted if it's in good running order, and if there are any major issues, hopefully they will become apparent while it is in pieces...

Anyone got any techniques for noting and organising components during a total strip down?  ;)

Oh, and Matthew, where you mentioned your engine having the 'worst assembly job ever' I'd be a little more reserved and say that at may be the worst assembly job...so far

Rozabikes Tim:

--- Quote from: cinqmars2 on January 07, 2013, 03:14:51 PM ---Also some photos of my carbs for help with identification  ;)

This is after a good lemon juice + vinegar cooking, all need a full rebuild.

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Hi

carb finish looks good. What is involved more specifically with lemon juice + vinegar cleaning method you refer to? Were the carbs pretty clean and not oxidised to start with.

thanks,


Tim

cinqmars2:
Hi Tim, I had before + after pictures on my phone, but it was stolen a few weeks ago! Gutted.

They were not oxidised as such, they were just very dirty, a lot of set-in fuel and muck from years of avoiding any cleaning at all, the bodies were unevenly stained and discoloured. I found this photo on Google, this is pretty close to how mine looked. After a spray with some carb cleaner and a quick scrub to get rid of the looser stuff, I boiled them.

The method I used was to boil the carbs one by one in a large pan for about two hours each. Maybe five litres of water to one cup of lemon juice and a couple of capfuls of white vinegar to be certain. Although saying this, you can find all kinds of ratios online that people swear by, ranging from 10:1 to 1:1, I don't think citric acid will really inflict any real damage to carbs. They were completely dismantled to get into as many little places as possible, if I had the means I would have liked to have used an air compressor to blast out the remaining water, but had to let them dry on top of my wood burner instead, wanted to get any moisture out as soon as possible.

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