Convert poor running |
Post Reply | Page <123 |
Author | ||
Brian UK
Moderator Group Joined: 13 May 2014 Location: Surrey Status: Offline Points: 17641 |
Post Options
Thanks(0)
|
|
Yes, cut the engine at the point it loses power then look at the plugs.
Sooty or white will tell you which is missing. But if the colour is still that perfect light brown then it must be another cause.
|
||
Brian.
Better 5 minutes late in this world than years early in the next. |
||
c13pep
Senior Member Joined: 31 Aug 2017 Location: Doncaster Status: Offline Points: 2110 |
Post Options
Thanks(0)
|
|
Pretty soon it became apparent that the bike would happily cruise at 50mph, but if I tried to accelerate beyond that, the motor would become "fluffy" and lose power until I closed the throttle a bit, and which point it would resume cruising at 40-50mph./QUOTE]
This fault mirrors exactly what occurred on my V50/3 last year and finally solved by this forum. I removed the air filters (K & N type) and the bike ran fine on a short test run thus when I inspected the Chinese K&N s they were severely restricting the air flow, hence wouldn`t go faster than 50mph, replaced air filters for non restrictive type and bike ran brilliant. CHRIS |
||
you can`t have any fun in a straight line
Monza Honda CB77 project |
||
Ken-Guzzibear
Moderator Group Joined: 13 May 2014 Location: Sileby Leics Status: Offline Points: 9454 |
Post Options
Thanks(0)
|
|
quick thought stuck choke msybe
|
||
The Older i Get, The Better I Was
|
||
Hyline
Falcone Joined: 08 Oct 2017 Location: Bristol Status: Offline Points: 82 |
Post Options
Thanks(0)
|
|
The plugs are grey in color.
|
||
Brian UK
Moderator Group Joined: 13 May 2014 Location: Surrey Status: Offline Points: 17641 |
Post Options
Thanks(0)
|
|
At what point did you check the plugs, this is critical. Did you cut the engine and check when you were experiencing the problem or did you wait till you got home?
|
||
Brian.
Better 5 minutes late in this world than years early in the next. |
||
jpc
Senior Member Joined: 06 Oct 2016 Location: Belgium Status: Offline Points: 651 |
Post Options
Thanks(0)
|
|
It's a two hour fault-finding job, been going on for a week.
Pet theories don't fix engine troubles, checking systems does. "Just saying".
Edited by jpc - 12 Apr 2018 at 10:21 |
||
iansoady
Senior Member Joined: 23 Jul 2017 Location: Redditch Status: Offline Points: 2402 |
Post Options
Thanks(0)
|
|
Plug chops with modern petrol are not very reliable as the additives can give misleading results.
|
||
Ian
1952 Norton ES2 1986 Honda XBR500 1958-ish Greeves/Triumph in progress |
||
Brian UK
Moderator Group Joined: 13 May 2014 Location: Surrey Status: Offline Points: 17641 |
Post Options
Thanks(0)
|
|
All depends on the owner's knowledge. While you might think it a short fault finding job, others would have some difficulty with this. Yes Ian, I know modern fuels can give misleading results, but you can't mask a very rich or very weak mixture. And here we are talking of extremes to cause this problem.
|
||
Brian.
Better 5 minutes late in this world than years early in the next. |
||
Ken-Guzzibear
Moderator Group Joined: 13 May 2014 Location: Sileby Leics Status: Offline Points: 9454 |
Post Options
Thanks(0)
|
|
As always if you can't find a fault looking at the obvious get someone else to look .in the past I have known someone spend literally a few hundred quid, tearing their hair out replacing parts to find it was a fairly simple fix done by someone who knew their way around a particular bike
It is real difficult to diagnose an issue when you can't see or hear the bike If the fuel is flowing well to the carb input then pop the carbs off they are very easy to look at and blow through .... Save yourself grief after that and get someone to do it for you, often the most economic route!...Not everyone is brill at everything .... |
||
The Older i Get, The Better I Was
|
||
Hyline
Falcone Joined: 08 Oct 2017 Location: Bristol Status: Offline Points: 82 |
Post Options
Thanks(0)
|
|
Yep, you are absolutely correct and I have reached that point. Many things are easy when you know how to do it - unfortunately I have very limited knowledge regarding carbs & electrical faults so the bike is going to someone next week who hopefully will resolve the issue quickly. As a quick update, I realised my bike only had one gasket where the carb attaches to the cylinder instead of two and it was also missing the fibre sealing washers. I fitted the missing parts and now the bike accelerates up to 70mph easily, but when slowing down a misfire is definitely very apparent. On getting home I took the plugs out and both were light grey in colour. But, as I said above it is now going to go to an expert to sort out. Thanks again for all the advice which was very helpful.
|
||
jpc
Senior Member Joined: 06 Oct 2016 Location: Belgium Status: Offline Points: 651 |
Post Options
Thanks(0)
|
|
I know, I've been there like everyone else. Which is why it helps to acquire a method early on as I tried to explain on page 2 of the saga: 1) DIST 2)IGN 3)CARB. It's at most a couple of hours of simple steps, a more humble attitude than "theorizing" the cause. This method moves you from prime to secundary causes, for instance avoiding obsessing with carburation when auto advance is stuck, or with ignition when valves don't close. Or getting fed up after a week of getting nowhere...
|
||
Dave P.
Senior Member Joined: 12 Jan 2015 Location: Northants Status: Offline Points: 5573 |
Post Options
Thanks(0)
|
|
There is also the old adage that "Most carburation faults are electrical" Just a thought.
|
||
TO LIVE OUTSIDE THE LAW YOU MUST BE HONEST.
1971 V7 Special. 1972 850GT. 1970 T120 Bonnie. 2009 500 Bullet. |
||
Ken-Guzzibear
Moderator Group Joined: 13 May 2014 Location: Sileby Leics Status: Offline Points: 9454 |
Post Options
Thanks(0)
|
|
Be interesting to find out what is causing the issue, whilst we can theorise, being with the bike seeing and hearing it makes a World of difference. The 2 inlet gaskets are to stop the vapourising of the fuel when it gets hot, later bikes did away with that by having a rubber inlet, which caused different issues ...banging and popping on over run is often air getting into exhaust ....
|
||
The Older i Get, The Better I Was
|
||
Brian UK
Moderator Group Joined: 13 May 2014 Location: Surrey Status: Offline Points: 17641 |
Post Options
Thanks(0)
|
|
Hadn't heard that one.
|
||
Brian.
Better 5 minutes late in this world than years early in the next. |
||
Post Reply | Page <123 |
Tweet
|
Forum Jump | Forum Permissions You cannot post new topics in this forum You cannot reply to topics in this forum You cannot delete your posts in this forum You cannot edit your posts in this forum You cannot create polls in this forum You cannot vote in polls in this forum |