46
British Bikes / Re: Velo Viper
« on: May 11, 2022, 08:20:19 AM »
Timing - I'll read the manual and check it! Appreciate POs...
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47
British Bikes / Re: Poor running - very smoky!
« on: May 11, 2022, 08:17:01 AM »
R
Yes indeed. Was thinking about it last night and came to a similar conclusion - flooding of some sort. Thing is I never touched the float/needle set up, but yes, I think the answer is in there somewhere!
Yes indeed. Was thinking about it last night and came to a similar conclusion - flooding of some sort. Thing is I never touched the float/needle set up, but yes, I think the answer is in there somewhere!
48
British Bikes / Poor running - very smoky!
« on: May 10, 2022, 10:03:52 PM »
Gents
Velo Viper with a Monobloc 376 carb which I have just overhauled. Put the carb back on and the bike is now a pig to start and when it does, it misfires amd smokes very badly. Ran fine beforehand
Everything was blown through, all jets correct, but obviously the carb came off and was put in all manner of positions - inverted etc.
My thinking
Stuck float - but it seems free - worked fine beforehand.
Float Needle valve stuck in the seat or not operating
A pointer perhaps. When the engine was running - badly - I turned the petcock off, let it run badly and after about 20s or so, it picked up revs and began to run far bettter for about 5 or 10s before dying of fuel starvation presumably.
All clues gratefully received!
Velo Viper with a Monobloc 376 carb which I have just overhauled. Put the carb back on and the bike is now a pig to start and when it does, it misfires amd smokes very badly. Ran fine beforehand
Everything was blown through, all jets correct, but obviously the carb came off and was put in all manner of positions - inverted etc.
My thinking
Stuck float - but it seems free - worked fine beforehand.
Float Needle valve stuck in the seat or not operating
A pointer perhaps. When the engine was running - badly - I turned the petcock off, let it run badly and after about 20s or so, it picked up revs and began to run far bettter for about 5 or 10s before dying of fuel starvation presumably.
All clues gratefully received!
49
British Bikes / Re: Velo Viper
« on: May 10, 2022, 09:44:04 AM »
Well - valve clearances are miles out. At least 14 thou on ex - should be 8. Inlet to check. This may be the root cause of the rough idle. I have not actually checked these - my mistake, as I was thinking of the MSS which of course is similar - but I was assured by the PO that all was good. Clearly not! Makes me wonder about the timing now!
50
British Bikes / Re: Velo Viper
« on: May 09, 2022, 09:24:43 AM »
Valve clearance seemed OK last time I checked.....I'll take another look whilst the tank is off.....
51
British Bikes / Re: Velo Viper
« on: May 09, 2022, 08:48:42 AM »
Gents
I have pulled the top off the old carb (Amal monobloc 376) to inspect things and the slide looks new and the bore does not look worn or scored. There is for sure a very slight amount of play, but I can't believe it is significant. Before I tinker about with the replacement carb, is there anything else I should be looking at for causes of a rough idle? So far, I have cleaned the idle air passage, the mix screw, the pilot jet, checked the gasket and faces to the head. Anything else carb related I should look for? Anything else non-carb related I should look at perhaps? Spark seems OK - mag overhauled not long ago.....
Thanks as ever
I have pulled the top off the old carb (Amal monobloc 376) to inspect things and the slide looks new and the bore does not look worn or scored. There is for sure a very slight amount of play, but I can't believe it is significant. Before I tinker about with the replacement carb, is there anything else I should be looking at for causes of a rough idle? So far, I have cleaned the idle air passage, the mix screw, the pilot jet, checked the gasket and faces to the head. Anything else carb related I should look for? Anything else non-carb related I should look at perhaps? Spark seems OK - mag overhauled not long ago.....
Thanks as ever
52
British Bikes / Re: Velo Viper
« on: May 02, 2022, 11:06:54 AM »
I have just poked my finger into the carb intake and wiggled the slide. There does appear to be movement. Mark M - what do you want for your body!
53
British Bikes / Re: Velo Viper
« on: May 02, 2022, 10:52:25 AM »
Ian
Yes - I thought it was emulsified oil also - hence the change. Boot looks fine. All a bit odd.....
Ref idle - yes worn bore/slide makes sense. I'll give it wiggle and revert if it moves about.....
Yes - I thought it was emulsified oil also - hence the change. Boot looks fine. All a bit odd.....
Ref idle - yes worn bore/slide makes sense. I'll give it wiggle and revert if it moves about.....
54
British Bikes / Velo Viper
« on: May 02, 2022, 08:30:34 AM »
Gents
Checking the oil level in the gearbox of my 1958 Velocette Viper, I found green khaki stuff oozing from the level plug. Feeling I ouught to be better safe than sorry, I drained it and put clean GP50 in. Any ideas what this stuff is? I assume some sort of specialist gearbox oil?
Gearchange feels a little notchy also. Nowhere near as smooth as the MSS - clutch adjustment perhaps?
Bike seems to run OK, but on idle it remains on high idle after a run, then settles down, then occasionally stalls. I have fiddled with the idle and the air mix screw, and cleaned the latter out. No real difference. No discernible air leaks either. I seem to recall this being a symptom of a poor mixture. Can anyone confirm please?
Checking the oil level in the gearbox of my 1958 Velocette Viper, I found green khaki stuff oozing from the level plug. Feeling I ouught to be better safe than sorry, I drained it and put clean GP50 in. Any ideas what this stuff is? I assume some sort of specialist gearbox oil?
Gearchange feels a little notchy also. Nowhere near as smooth as the MSS - clutch adjustment perhaps?
Bike seems to run OK, but on idle it remains on high idle after a run, then settles down, then occasionally stalls. I have fiddled with the idle and the air mix screw, and cleaned the latter out. No real difference. No discernible air leaks either. I seem to recall this being a symptom of a poor mixture. Can anyone confirm please?
55
British Bikes / Re: Balancer chain
« on: March 29, 2022, 10:23:22 AM »
Murdo - Interesting, and I don't see an obvious reason why a split link should not be used....
Ian - thanks for the link - pun intended.
Ian - thanks for the link - pun intended.
56
British Bikes / Re: Balancer chain
« on: March 28, 2022, 08:04:35 PM »
Ian
My thinking is that the amount of side/lateral force - for want of better words - cannot be that much, its not subject to that much torque pulsation either, and a split link may well be OK. If it lets go then it would probably mash something inside the crankcase cover, but then again I have never had a split link let go before - even on cam chains. Who is the chain man please?
My thinking is that the amount of side/lateral force - for want of better words - cannot be that much, its not subject to that much torque pulsation either, and a split link may well be OK. If it lets go then it would probably mash something inside the crankcase cover, but then again I have never had a split link let go before - even on cam chains. Who is the chain man please?
57
British Bikes / Balancer chain
« on: March 28, 2022, 04:23:30 PM »
Quick Q - I have replaced the balancer chain on the Honda 250 single - and yes I am taking liberties with a Jap bike! This chain is about the size of a bicycle drive chain but needs cutting down to size. This is not an issue, but various folk suggest a rivet link to join it. I have no experience of rivet links, no tool, and no-one up here can seemingly assist. Will a split link in lieu be too much of a risk?
58
British Bikes / Re: Erratic chronometric
« on: March 28, 2022, 08:14:04 AM »
A few drops of wd40 seems to have sorted it....I like simple solutions.
59
British Bikes / Erratic chronometric
« on: March 25, 2022, 04:54:06 PM »
Gents
Smith chronometric speedo on a 55 Velocette MSS has developed a fault. Basically it is reading very low - reads 10 mph when shoud be 40 or so. Mileometer works, cable looks OK, no sharp turns or kinks in the cable. Fine yesterday!
Clues appreciated.
Thanks as always
Mark
Smith chronometric speedo on a 55 Velocette MSS has developed a fault. Basically it is reading very low - reads 10 mph when shoud be 40 or so. Mileometer works, cable looks OK, no sharp turns or kinks in the cable. Fine yesterday!
Clues appreciated.
Thanks as always
Mark
60
British Bikes / Re: F-B 250 cruiser 80
« on: March 10, 2022, 08:03:27 AM »
Chaps
Many thanks for all the useful advice. It is always much appreciated. To doubtless make you all recoil in horror, I plumped for a 1980 Honda CB250RS instead! I wanted something relatively cheap and simple to mess about with for the moment and this thing was too good to miss. Heaps of spares and in very good condition. I'll strip it down just for the hell of it and re-assemble with all consumables replaced and everything cleaned up. Didn't have much luck on the British front. A Bantam seemed to be the only thing on offer in the price range (@ 1000-1200) and plenty of moped type things, but nothing else took my fancy. The vast majority of it was also over-priced and some of it was simply scrap. Besides which, my Venom needs finishing off so that will sate my national pride for a while yet.
Many thanks for all the useful advice. It is always much appreciated. To doubtless make you all recoil in horror, I plumped for a 1980 Honda CB250RS instead! I wanted something relatively cheap and simple to mess about with for the moment and this thing was too good to miss. Heaps of spares and in very good condition. I'll strip it down just for the hell of it and re-assemble with all consumables replaced and everything cleaned up. Didn't have much luck on the British front. A Bantam seemed to be the only thing on offer in the price range (@ 1000-1200) and plenty of moped type things, but nothing else took my fancy. The vast majority of it was also over-priced and some of it was simply scrap. Besides which, my Venom needs finishing off so that will sate my national pride for a while yet.