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Need some advice on issues/help

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smace78
Squiddy
Squiddy

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Need some advice on issues/help

Post by smace78 on Tue 19 Jan 2016, 10:55 am

Hi

I am in need of some help as I have had bad experiences with the garages around my area so would like to try and fix the problem my self.

Now the issue I have is the spark plugs are covered in oil and the air filter and box had some fuel just a small amount that was nearly dry. Also the engine oil smelt of fuel.


1 year ago I had it rejeted 140 I think with the shims checked and they was ok. Also the carbs were sonic cleaned at the same time as well.

About 1 month ago I noticed that I had a loss in power and felt more sluggish. I then sent it in to be looked at by a garage but they said it was fine for the age of the bike.


Last week I got a weird issue that all my lights started to dim and turn on and off. I turned each one off one at a time and still had the same issue. The bike was running as normal but  later that day it was ok. Water in the connections?

I think the fuel in the fuel filter and oil might be the floats/jets clogged. The oil over the spark plugs could be the cylinder gasket but not sure. The light issue might be just water?.

I have done work on the bike before but have not taken the carbs or engine apart so any advice would be a great help.

Thanks
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eternally_troubled
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Re: Need some advice on issues/help

Post by eternally_troubled on Tue 19 Jan 2016, 1:44 pm

If you are getting a smell of fuel and you've got some in the airbox/air filter then I suggest that you might well be right and your float valves are malfunctioning and not stopping petrol entering the carb when it is full.

If this *is* what has happened then you want to check out some other things first, mainly you need to see if the fuel has leaked from the carbs into the engine and contaminated the oil in the sump. The easiest way to check this is to drain the oil out into a bowl (an old washing up bowl is great) and have a look at it - more importantly have a smell of it and see if there is any petrol there. You can also measure how much of it there is using an old jug or similar - if there is more than roughly 3 - 3.5 litres of 'oil' then something else has got in there.

If you have got petrol in your oil then you need to throw that oil away and get some more to replace it - don't put it in until you've fixed the problem with the float valves (if that is what the problem is).

You can diagnose the float valves problem by getting an external fuel tank (like this). You'll need to remove the main tank from the bike and connect this up to the fuel hose instead. Fill it up a bit with petrol and leave the bike to stand for a bit - the petrol level in the tank shouldn't go down at all if your float valves are working.

While you have the main-tank off the bike you should test that the vacuum fuel tap works correctly - you shouldn't get any fuel coming out of the tap (even in the 'on' position) unless a vacuum is provided to the vacuum tube (the small one coming from the petrol tap). You can create a vacuum by sucking on the tube - it only tastes slightly of petrol! This should turn the tap on (make sure the petrol pipe is over a container or you'll make a mess).

The vacuum tap (if it is working) should have stopped any petrol leaking when the bike is not running but you could have still had a problem *while* the bike is running.

You mentioned that your plugs looked oily - this could have been fouling caused by an overly high fuel level in the carbs, so it is worth cleaning them up (possibly with a bit of petrol as you have some of that lying around) and drying them out and trying to use them again (worth checking the gap while you have them out).

Was there a reason that you had the main-jet changed to a 140 size?

The electrical issue could be nothing to do with the fuel thing. It will be easier to diagnose that when you have the bike running again - it could be that your regulator rectifier is knackered (it's a common thing on CB500s - and lots of other bikes!). For now check your battery voltage - if it's less than 12 Volts take the battery off the bike and give it a charge.

Do you have access to a compression tester? If you are concerned about the head-gasket then it might be worth doing a compression test on both cylinders and seeing what you get - have a look in Haynes for the numbers.

The carbs aren't that difficult to take apart but you'll need some non-knackered, well fitting small screwdrivers, a clean place to take them apart and probably some little boxes for all the small pieces.

Anyway, good luck and keep us informed of what you find.
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ANDYC
the 900
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Location : Windsor

Re: Need some advice on issues/help

Post by ANDYC on Tue 19 Jan 2016, 5:21 pm

Are there any other mods to the engine to justify running 140 jets?
These may be the root of your problems.
Assuming the engine is standard, these would cause the mixture to run really rich which would explain your lack of power and sluggish response.
The plugs would get fouled very easily as they wouldn't be working at the temperature needed to burn off any deposits. This causes misfires, as there is no pressure acting on the piston rings it would allow oil past the piston rings into the combustion chamber and unburnt fuel past the rings down into the oil.
I would start with checking the jet sizes first, the std size is 122. The vacuum shut off in the fuel tap as previously mentioned is an easily tested item.
Electrics could be down to a bad earth, which are pretty common on just about any vehicle.
How old is your bike and what area are you located in?
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Alvi
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Location : Isle of Man

Re: Need some advice on issues/help

Post by Alvi on Tue 19 Jan 2016, 9:50 pm

ET & Andy have covered it pretty well, and there's nothing more I can add, but it's worth covering the problem I had with my bike. I got it for a song as a non runner that had been stood in a neighbour's garage for 5 years or more. The tank was empty, but even when I put fuel in it, I couldn't get it started & when I removed the dipstick, 'oil' gushed out. The contents of the fuel tank had emptied into the sump! I changed the oil, replaced the plugs & eventually got it started, but it ran very rough, popping & spluttering. I took the carbs of & checked the float bowls, but they looked ok, so I just put them back & it ran much better. Then I realised the airbox wasn' t connected as I'd removed the rubbers to get the carbs off & on. Put the rubbers back & it ran rough again. Removed the air filter & it ran fine. I cracked on with the rebuild then. I meant to keep the filter to check it out, but forgot & threw it out with some other stuff. I reckon fuel got in & broke it down, clogging it, but I can't be sure. I never did much with the float valves, but may have cleaned them up a bit. I stripped the fuel tap, but couldn't see anything wrong with it. Got the bike rebuilt, tested & clocked a few miles up, then one day it wouldn't start. Checked the oil & it was above the full mark. At that point, I got another fuel tap of ebay. That was 10 months & 5k miles ago & I've never had a problem since - starts first time every time & runs fine. I don't really know what the whole problem was, but somehow, the fuel tap seemed to be involved.
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smace78
Squiddy
Squiddy

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Re: Need some advice on issues/help

Post by smace78 on Wed 20 Jan 2016, 6:21 pm

Thanks for the information this going to be a great help.

Fuel was found in the engine oil.

I have ordered a aux fuel tank, a tap refurb kit, compression tester and a carb cleaner hoping it will clear the carbs. These should turn up tomorrow maybe friday.

The bike is 13 years old one of the 02-03 model CB500s was not looked after by the other people that had it so have had issues for 2 years streight then 1 year no issues. So had it for 3 years now.
The bike gets daily use as I use it to commute to and from work all year round. 22 miles a day 5 days a week.

I have an early finish at work tomorrow and will have a look and will provide an update later.

I have done most of this my self with the information that everyone here has shared.

Done (In the last 3 years)

Radiator
Radiator Fan
Coolant Temp Sensor
Coolant hoses
Stator (Rebuilt)
Rectifier (Upgraded to a new version)
Battery (1 year old) Motobat 10ah
Hanndle bars
Fuel exhaust
Downpipes (Stanless steel)
Jet Kit (For exhaust was getting popping and backfires) It was a well known kit got the information here.
Fork tubes rebuild
Hagon fork springs
Hagon rear shock
Accesories fuse box (Under seat)
Fog/Spot Lights
Daytime running lights
Heated grips
Handguards with LED Lights
GripPuppies
LED Mirrors
Front sprocket (Standard)
Rear sprocket (-2)
Chain
Scottoiler
Braided brake hoses
Reconditioned the brake calipers
Sprocket Cushion Rubbers
Replaced the rear master cylinder
New Discs front and back

Just done
ZXF1000 throttle tube
Ties Front and Rear

Removed Upgrades
Hid Projector kit (Taken off did not work well with headlight failed MOT)
LED H4 bulb (Taken off failed MOT, Spread the light all over the place) This was a known one that was recommended for other bikes.


Battery & charging conditions
v12.3 - Turn on but not running
Above v13 - when running but not warmed up
v15 - once it is warm and idling around 1300 rpm
v14.5 - when main headlight is on and running

Charged last week on a DataTool charger over the week end but did not see any improvement
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eternally_troubled
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Re: Need some advice on issues/help

Post by eternally_troubled on Thu 21 Jan 2016, 12:04 pm

That's a good amount of stuff you've done in the last three years Smile

You should post a picture of the bike when you've got it going again.

Those figures for the battery voltages look about right, so it's probably not your regulator rectifier.

You mentioned that the previous owners weren't too good - is it possible that they hacked around with the electrics to put in heated grips etc? Dubious modifications are often likely to fail first IME (sometimes I am fond of dubious/bodged modifications, so I know how they do wrong!).

Also, when you said your 'lights' were failing did you mean the idiot lights and clock lights? If so, I had a similar problem - it turned out to be a broken wire in the bundle that runs up the head stock - a common problem eventually caused by the flexing that happens when you turn the bars.

You mentioned you had a Fuel exhaust - I'm pretty sure that 140 sounds a bit big compared to what other people have used (I can't remember right now but 125 sounds more familiar - the standard jet is 122). Also you can often get popping even if the mixture is correct... the backfires might have been caused by something else.

Given you've found fuel in the oil, which can only happen if one or both of your float valves are failing, I'd say it's worth thinking about having a look at/testing the float mechanism.




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ANDYC
the 900
the 900

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Location : Windsor

Re: Need some advice on issues/help

Post by ANDYC on Thu 21 Jan 2016, 12:39 pm

I run an SP silencer and many other mods, these only need a 125 main jet. I did run 128 mains until the dyno proved it to be running richer than ideal.
The popping is probably caused by an air leak, or the most common cause these days is a combination of valve overlap (the inlet valve opening before the exhaust valve is fully closed) and lack of back pressure in the exhaust system(to prevent the fuel/air mixture passing straight from the inlet valve to the exhaust).
This is why the original exhaust causes no popping, it provides enough restriction to create back pressure. If you still have the original one, try it and see.
Many bikes these days have servo operated valves in the exhaust system to create back pressure at low revs whist still having a free flowing exhaust at higher revs.
I have to admit that the popping on mine irritates the hell out of me, I believed originally that the jets were the problem. Only when the dyno showed the air/fuel mixture did I realise that no end of jetting was going to change things that I had to put up with it.

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