Big problem this time - bike sounds like a sewing machine and no power

[moko]

No cam bearings ... the thing just runs directly on the head. Even somebody like me who doesn't know much about engines was surprised to see that.

Something Honda were notorious for.250RS was a best-selling bike in Britain and far too many got taken out when they trashed the heads because of the lack of bearings,hardly any left in fact.Lots of Chinese trail-bikes sold over here now,they`re mainly XL125 and 200 copies BUT the Chinese have modded them with camshaft bearings.SO,not only are they copying Honda but also improving them,think that says it all for the future.

[lb99]

3 of them I think, thats the bit the cam spins on in the head, but the are made out of the same stuff the head is (chocolate!), they dont have replaceable shells like they should. so when you run a bit short of oil, the first thing to go are the crappy bearings in the head, Have a look at those bits on the head and the inside of the rocker cover, as well as at the corresponding bits on the cam, do they look hammered? like excessive scoring?. I talked to the guy I know, and he will have a look, it would probably take a few days, though, but it will most likely be cheaper too, this guy has these motors coming out of his ears, its just a matter of finding a good head (maybe even a black one), when you do put it back togeater, make sure the oilways are clear, it think it might get pumped up beside one of the head studs, anyway its easily blocked, so be careful.

[xwhatsit]

Oh I think I know what you mean now, just the surfaces that the camshaft sits on? Like, not actual moving bearings like ball bearings or taper bearings, but just the surfaces the shaft touches? I will have a look when I take it apart (hopefully tomorrow after my last exam). I'm pretty sure last time when I took it to bits it was in good shape, the camshaft looked fine... but I wasn't paying too much attention it must be said. Before putting it back together I just put a wee bit of oil on the bearing surfaces before replacing the camshaft, I thought it was probably prudent as when I started it up the first time oil was probably not everywhere it should be. Anyway I'm off to work... thanks for your help lb99! You're a champ ^_^.

[gijoe1313]

Sorry to hear about all the wonderful ways of learning your way around a bike Xerxes! Seems you are having a ton of fun getting oil under your nails and playing with the tools - hope you get your bike back into running order soon so we can go out for a nice little tootle after your exams!

If you need a hand or anything, just sing out!

[xwhatsit]

Cheers gijoe, yeah I am enjoying myself despite the huge inconvenience of having to catch the bus. Gah I hate it. And it costs me $10 a pop too.

But no I pulled it down after my last exam this morning, it's the same problem... at TDC the exhaust valves don't line up. Interestingly it's the same valve again, so it seems that peening the head around it wasn't quite as effective as thought. I've half a mind to put it together back again, do the same thing again (but somewhat more securely) and keep riding until I can procure a head from god knows where.

This time around I made a more careful note of what I pulled off, and was able to do it with far less disturbance to the rest of the bike (i.e. didn't pull out half the electrics), and also kept a careful note of the general condition of things. As I mentioned earlier, half the bolts are non-standard - but what was really bizarre was a couple of the bolts going through the head cover into the head were not metric, but only fit my imperial sockets! Wtf! They were 7/16ths or whatever the imperial one is starting with 7. I think at some point in it's life somebody has abused the bejesus out of the bike, especially the head. The piston/bore etc looks pretty good, it's just the head... I wonder if the head is not original either?

lb99 I checked out those bearings, and camshaft -- it looks pretty good. There are a couple of scratches on the head cover bearings, but they don't seem too bad, are small and there's maybe only 3 or 4 small scratches. Camshaft looks sweet, although I half wish it were broken so I could upgrade it to the CB250RS-D model 33HP camshaft and accompanying head ^_^. Of course then the head wouldn't be black and might look a little strange on an otherwise black engine, but I can live with that for an extra 7HP lol.

I've also decided that I want to get hold of some new exhaust collets, as the left hand side pair are pretty much more rust than metal; the right one is OK but could probably stand a replacement.

Hanging out to get this engine fixed up... I can't wait to get back on the bloody thing, and catching the bus is a bit of a nightmare, both financially and time-wise -- last night I left for work at about 4.30, started work at 6.15 (I only got there at 6.00), finished work at 8.30 (no customers, Guy Fawkes), got home at 10.40. So I spent $10 on a bus for earning perhaps $20 after tax, so I made perhaps a little more than $10 for being out from 4.30 to 10.40 - 6 hours. Please come back to life, Miss Honda! .

[xwhatsit]

Woooo so I bought the Econohonda head, spending $10 a day in bus fares suddenly made the $200 price for a new head look less silly. Anyway, I don't know how long it will take to get here, the guy does overnight shipping but the money might take up to two days to clear according to my bank, and of course he's actually got to get the head from whatever it's attached to as well. I should think it would be hear by Friday though.

Anyway, feeling in a motorcycling mood, I decided that despite having a new head very shortly I wanted to ride the bloody bike so I put it back together after re-seating the valve ring and munging some aluminium over it again. Looks horrible, but the engine started perfectly and seemed to run OK. Went for a quick circuit around the block and came back and called it a night. Man you get a sore arse riding without a seat ! Not recommended.

So that's two top-end rebuilds, and soon to be a third... with fingernails like mine I think I should give up this maitre d' lark and become a miner ^_^.

[xwhatsit]

OK, yet another post in this epic tale of a less-than-mechanically apt beginner biker.

Bike, unsurprisingly, threw a valve seat again on the way home from work haha. Ah well I'm learning. Got an email from Mr Econohonda (Malcolm?) who told me... `the head I was thinking of is suspect, will get you another one instead, sorry will be an extra day'. I'm happy with that. Some bastards would just throw the munged head at me. I got another email today saying `couldn't find another bare head, so I'm sending you a good-condition head with valves in it, for the same price'. Woot! Save me from busting my arms pulling valves out and back in four times! Supposed to reach here tomorrow sometime.

Here's where I need advice, though. The existing head is pretty shagged, with threaded bolts everywhere. The valve cover, however, is in reasonable condition; or at least it was until yesterday I managed to completely root the thread which holds the rev counter drive into the head. This thread is not in the head, it's on the valve cover. Arse. This is, of course, not a critical thread; not holding anything important together. However, it does cause a pretty bad oil leak as the thread is so stuffed it doesn't hold the tachometer drive to the engine tight enough to prevent oil leakage. I epoxied the gap up, after reading a couple of posts which vaguely suggested something like that, but I would like to do a proper job.

My question is: helicoil? Is this something I can do myself? How much are they? The valve cover is made of (as lb99 put it) chocolate, (or aluminium), will the helicoil stay in there properly?

Any other solutions? Thanks guys.

[lb99]

OK, yet another post in this epic tale of a less-than-mechanically apt beginner biker.

........
My question is: helicoil? Is this something I can do myself? How much are they? The valve cover is made of (as lb99 put it) chocolate, (or aluminium), will the helicoil stay in there properly?

Any other solutions? Thanks guys.

just take the cover to a reputable shop to get a helicoil fitted, it shouldn't be too dear, you can buy a kit, but its not worth it just for one coil, I remember getting a whole lot done in one head for about 6 bucks each a while ago in dunedin.
a good epoxy will probably do it, as the drive is kind of clamped in place between the rocker cover and the head, I'd give it a go because that shows how tight I am

good score on the head, Malcolm is a top bloke, its good to see new bikers getting looked after.

Good luck

lb99

[MSTRS:Me]

Can you plug it with KneadIt, then drill and tap a new thread in????

[xwhatsit]

Oh, I thought just one coil came in a helicoil type thing? So it's not, say, a sub-$20 thing I can buy from Repco and do with an electric drill? Ah well I'll give an engineering shop a go; any recommendations from anybody? Bear in mind that I'm pretty broke hahaha. This bike better give me some love after throwing 75% of my income at it! Lol.

Yeah, epoxy might be a temporary solution... as you say, it's pretty solidly held in place between the head and cover anyway, so I'm not worried about it coming loose. It's just the oil leak.

Yes, this Malcolm guy does seem to be a pretty good guy. I've mostly talked to him on email but I called him up when I actually purchased the head; he obviously knew I am not the most clued-up biker in the world and asked me a whole lot of questions to ascertain I was after a CB250RS head and not a CBX250 head. Much better than the people I've encountered in certain (unnamed) shops who have been too lazy or patronising to help a newbie biker find a spark plug for his bike.

[gijoe1313]

Crikey - your missus might throw a wobbly if you've thrown 75% of your non-disposable income at another girl! (even if it's a pyscho hose beast!) Sounds like you're getting valuable biker experience in fixing your ride up. Anything else after what you've gone through will be a doddle!

[xwhatsit]

Psycho hose beast? Is that a `lifestyle assisting product'? Maybe Dover's missus would be pleased if he spent lots of money on one of those?

Well 75% of income is piss-all when you're a low-paid maitre d' and studying. For the record though, girlfriend is not well-pleased by the bike, after binning, and especially after my hands smelling like oil and looking dirty even after scrubbing them for half an hour haha.

Oh well, I now have valuable relationship experience, in keeping happy a) one cute but full of worry HK girl, and b) one cute but full of expense Japanese girl ^_^. I'm glad neither read this forum.

[MSTRS:Me]

.... my hands smelling like oil and looking dirty even after scrubbing them for half an hour haha.

Use a dollop of dishwashing liquid and a teaspoon of sugar, wet and rub into a paste all over your greasy hands. Rinse off. Barring under your nails, your hands will be clean & smell nice.

[xwhatsit]

Sugar, eh... tried dishwashing liquid, left hands smelling Lemony Fresh(tm), but still had oily-bits on the palms of my hands. Will try! Thanks for tip!

[gijoe1313]

Oh well, I now have valuable relationship experience, in keeping happy a) one cute but full of worry HK girl, and b) one cute but full of expense Japanese girl ^_^. I'm glad neither read this forum.

OMFG You are cruising for a bruising! Ah well hold onto the ride and enjoy the endorphins, when it all goes pear shaped on you, you can ride your bike like a bat outta hell (once you got the valves, connections, head, gaskets, rings etc. al back together!)

The pleasure and pain that only asian gurlies can bring ... you are a brave lad!

Basic formula : Asian Female = Psycho hose beast squared by the lack of common sense that has left the building multiplied by lack of adequate funding, style, food places taken to, presents, pious observations of obscure asian holy days and then rounded off to the nearest horrible dog box they can send you to!