Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.


Topics - Northy

Pages: [1]
1
CB350/400 / Odd spark problem
« on: January 19, 2020, 03:57:45 PM »
I've  think I sorted it .......but its a weird one (Northy what hell are you talking about !!  ::) ::) )

Well for few weeks I've had this problem with the special 400/4 . After about 8/10 miles it would lose number 2/3  cylinders with no spark.The more you used the revs the less miles you did, so heat related? however wait 5 minutes and it runs Ok on all four, for about 4-6 miles.
This was PIA as it fixed it self before you got to testing things.   >:(

But Coil I hear you say ! ::) ::)

So replaced the new DS one with an old one ..same result
Replace both coils and leads/cap from my other 400f ...same result
Swapped plugs ...same result 
Replaced the condensers from my other  400f, clean points (again) ...same result
Checking wiring/connecting ...all seem ok
Not water related as only used in the dry
Thinking of making up a new wires from the points to coil or pleading for help on the SOHC forum  ;D ;D

Then today I had a thought (yes the 2 brain cells clicked in) this followed yet another run of 10 miles, then it goes onto 2. What haven't I changed and what have I changed. As the other 400/f with the swapped out part runs fine.

Well it took 1 minutes to fix it ......I managed 22 miles with not even a misfire , lots of revs etc (by which time it was getting colder )

The possible culprit .....

[ Guests cannot view attachments ]

I don't know why but replacing this with the standard chrome points cover sorted it. I had fitted it a few months back. 

Its not clearance issue but the ally one does get a lot warmer then the chrome one .This could point to something (points/condenser) breaking down under heat. The final test is refit the ally one and see if I can make 22 miles. (way too cold now for that )

So I think its sorted but its an odd one .....anyone had issues like this ? 



 
 
 
   




 

 

2
CB350/400 / Mystery - Gutless 400 four
« on: December 04, 2018, 05:18:26 PM »
Ok Folks , brought a 400 from mate , never do that with recorded mileage of 9k (mot's  to back it up ) but he couldn't  get running right . I got running better but its gutless and has other issues.
Here the symptoms  :-
On start up smokes , but clears .
Pulls fine up to about 4.5 k then misses ,no power can rev it up to 8 k but feel like it missing on one pot, hot or cold
Not go above 60 !! feel like sock up the exhaust pipe
Using oil but once warm there no smoke or horrible noises
Oil is blacken within 200 miles
Compression 25psi lower than my other 400f on no's  1/2 same on 3/4 as comparison only.


So how you going through the thought process ...and coming to a conclusion but first this is what has been done, with no effect :- 
Swapped over Coils from running bike, carb sonic cleaned  checked x2  and then swapped over with another set , electronic removed back to points, new air clean and plugs, advance retard mechanism  checked 

However you I can hear shouting it the valve steam seals !! ...that covers the startup smoke and oil usage  agreed  so lets whip the head off have looks see. Expecting  broken rings as well 

First this head been of before ! and came  off to easy and the exhaust ports are very sooty

Umm  lots oil  so much the carbon comes off easy , note  one no.3  pot  is less oil and this confirmed by the colour of the plug
head


piston tops



So next was to remove the barrel , expect a ring to fall out ...hope all in one piece and then notice the are piston 0.5  O/S.


Bore with honing marking in place



So there looks to nothing to much wrong with piston / rings and quick check on the ring show all OK  and no slop in  bores .... could have been rebored wrong ?

OK move back to valves and just whipped one out  and it clear the valve stem seal are shot  see pictures but also note the perfect face on the valve  (plus loads of oil)   





So OK stem seals can account for oil on start up, oil usage,oil in bores (?)  but it would still run Ok and given that there no oil appears to burning pass the pistons.

However I cant see that the seals would have such a dramatic  effect on the power of the engine . Ok it can suck in oil and air and weaken the mixture but never this bad or has the thing not run in yet ?         

Tomorrow I will check the bore/piston and all the valves 

So what am I missing (apart from few brain cells !!)



   







   

3
Project Board / CB400 Four special (Mr Sinx II )
« on: October 09, 2018, 08:02:44 PM »
Right any purist please look way now before you go mad and say why wreck cb400f and make special out of it .

OH also long thread alert …if your bored just look at the pictures ;-) Oh will be lots of typos as well   :D

Why a 400 four ,well back in 70/80 I created this and number of variations and still had standard yellow one VKK 333S.


 I sold the bike in 1993  for £350 plus a mountain of spares (DOH !! ) well the engine had done over 150k, was on its second frame, iffy wiring and even the ARE alloy wheels where a bent in places. Ironically nothing I couldn’t fix now. So some 30 yrs on , my spannering skills are better than that poor cheeky kid on the “flying tampon” as mates  used to call it. Its was called Mr Sinx, after our cat (bloody vicious thing!)

Well at the time of writing I have two other 400f that are rolling restorations. 2 frames and yet another mountain of part worn 400 bits. Also over the last few years done a few restoration to high standard and a couple of specials.(read I’m handy with spanner and a picky sod too)

So this will be a recreation of Mr Snix but I might move away from the clip ons etc , so more like the Mocheck Harrier (to save my back & wrists). So I’ve already have picture of how it will look in my head and I know what I need but finding them and making them fit is the fun bit  (need a set of Alloys)   

So where does ones start with just frame, engine and plie of bits …the carbs of course. I needed a clean set for one of the other bike which was suffering odd running.(turned out to be the coils). The Bike bits had been sitting for excess of 7yrs in  garage (working one with sooty diesel, brake dust and damp etc )  So the carb where stripped right down 




Tip one , don’t disassemble the rod mechanism if don’t have to. The rod that runs across the carbs to link them together runs in two bronze bushes. However there is also a brass pin in one mount that hold the bush in place and locates pin on the rod. To remove the rod you need to drill out this brass pin or the bush with break up if you try to remove the rod. However drilling out the pin a PTA its only 3mm dia and can easy go into the ally mounting. See picture even drilling the pin didn’t help cracked anyway!!
So some clean carbs , a with re-plated metal bits. I used stainless bolts and this not going to standard anyway.

 
Good job I've spare set of carbs

So next engine, I wasn’t expecting great things from this. The clock said it had done 43,000 miles and it showed signs of previous split cases and nasty bodges. As I was  stripping this down to last bits, I didn’t bother deep cleaning it before hand


Ohh err


The thread on bolt that locks cam chain adjuster had been chewed up badly but managed to heli coil it. Phew

Spot the odd one out


Two head bolt where finger tight and the cam chain was starting chew its way into the adjuster (they all do that sir). Which is why there was no wear on the guides.
Then the good news the clutch looked like new. I even found my old home made clutch holding tool in the not use often “tool box” last used  25 yrs ago



The primary chain, is very sloppy and need a new one of those. The bore was OK , with marking where the piston had been and still on standard piston bit all looking a bit tied with one broken ring. I measured them all up and there just outside the recommended tolerances, could put new std piston and new rings  and it would run but it deserves a rebore.





So do I go for the oversized 54mmbore kit or just take it 0.25mm OS. The cost using kits from Cruzinimage_uk is the same. I tempted by the big bore (sounds good and gains brownie point when talking bollocks at the cafe)  but then reality kicks in and its only  on a 400  if I need to go faster there’s an modern 750 in garage.   However welcome your thought on this ??.


There was much sludge in sump and bottom of the cases but hardly any metal bits …all good.

Main bearings all Ok but the big end showing wear so they will be replaced ….bloody expensive at £10.74  per half shell ….


All the valves have been removed and the head looks in fine shape no damaged fins, rocker spindles with bit of wear and valve seats good.Cams  all good , wear but nothing  bad.
So no sheared screws or bolts, expect general wear no nasty surprises and only two threads required a helicol. I do them when I see on strip down as the stuff is going to be cleaned after so any bits of ally get washed away.  Not bad at all it would have run no doubt but no very well.

Tip 2  Rotor removal is required for replace the end seal and best  done once the crank removed,. you can’t do without splitting the cases due to the lip on the seal. You could take a hammer to it, dig out the special tool (if you have one ) with a 18x1.5 thread it to “pull” the rotor  off. However the thread a size is the same of many car sump plug or Lamaba sensor plugs available for £2.  Sorted !!   


Next ……the case of clean the cases!!
     
Got quoted £140  to vapour blast the  cases,head. barrels etc  .......Sod that, out with chemicals.

4
New Member Introductions / Another new one from kent
« on: July 25, 2018, 11:47:32 PM »
Hi
Thought I'd join you merry lot  as I'm back in SOHC fold with 3 & 1/2  Honda 400  fours. I can't just buy one can I ! ::)
 
The last one I had was sold for peanuts in 1993 and I avoided buying another due to rose tinted glasses effect, suspect I got a bit bored with them and was playing with bigger bikes.
 
So I've had a few (400/4) in my days, I know these babies quiet well and hopefully pass on some tips and progress on the 3.5  bikes , 2 will done up as standard not sure on level but I do tend to get carried away (so say good bye to £££££££  ouch). The third will be a special based around the one I had in 70/80's (yes I'm that old !) as I'd like to think I'm a bit more skilled and have a more experience in doing up bikes. Now need sell some ! 

Piccy of Mr Snix  circa 1980



Northy

PS normally into guzzi's , yeah I know weird.





   

Pages: [1]
SimplePortal 2.3.5 © 2008-2012, SimplePortal