Spark plugs

[primalcarl]

My bike is running again, after fitting a new cdi. However, the guy who did it didn't have the correct spark plug and said it was misfiring a bit but if I took it steady I should make it home.

I took it easy, and had to keep the revs high. After about 6 miles and almost home, the engine died. I waited a few minutes and then it started again. It kept doing this, running for a bit then just dying.

I'm hoping this is just because the wrong spark plug is in the bike?
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Bikes: Honda S-Wing > Honda Varadero XL125V > Yamaha XJ6N > Honda Silverwing> CBR600rr > VFR 800 FI > R1200gs

[Kickstart]

Hi

It could be the plug, but personally I would doubt it. If it was wrong enough for the engine to die then I doubt it would restart.

I would think the most likely cause is either a kinked fuel hose or a blocked breather into the fuel tank, or possibly a blocked fuel filter.

All the best

Keith
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Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[primalcarl]

Thanks Kickstart.

When I go back to the bike later I will fit the new spark plug, and also check the fuel lines as someone else mentioned this. Will report back on what happens
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Bikes: Honda S-Wing > Honda Varadero XL125V > Yamaha XJ6N > Honda Silverwing> CBR600rr > VFR 800 FI > R1200gs

[Frost]

had this with my bike a few months back. i put some plugs in it to replace the unbranded ones previously in it. the ones which were in it before where i suspect incorrect. when they got hot the engine would cut out. i had people try to tell me i had ceased the bike, but it turned over fine, plenty of compression, fuel was fine etc. But i had to wait for it to cool down before i could use it again. since replacing the plugs ive not had the problem.


https://www.gear4bikes.com/acatalog/index.html

go there and get yourself a set of the correct plugs for your bike.

[badlydamaged]

Same happened to me as well, when it got hot after a few miles it started backfiring and died. Had to wait for it to cool down, otherwise the engine would backfire when kicking it over, waited for about 20 minutes, got on it and hobbled home, turned out to be the spark plugs
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My bike: 1988 Kawasaki KH100 Status: Polluting Devon with two stroke smog and noise pollution!
"Its not your engine size that matters!, It's what you do with it that counts"
Add me to MSN if you want! badlydamaged@hotmail.com.

[primalcarl]

This is what happens to me. I replaced the spark plug with the correct one (NGK BR8ES I think) and it starts fine but after a few miles the revs will start to die then it cuts out

Have just cleaned the tap filter and air filter, I don't know what else to do apart from taking the caburettor off and cleaning it
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Bikes: Honda S-Wing > Honda Varadero XL125V > Yamaha XJ6N > Honda Silverwing> CBR600rr > VFR 800 FI > R1200gs

[badlydamaged]

Hey again
Well my bike apparantly runs on B8ES which is what the manufacteurers recomend, and this was the plug that caused all the backfiring and cutting out, when replaced with new ones of the same it went for a while and then the same old thing started again. Now what I did is brought slightly hotter plugs, B5ES and used those ever since Iv'e had my bike on the road and I have had no problems what so ever, the Bikeshop spoke to a few people and found out that it was safe to put this temperature plug in my bike with no worries . I have heard of the same problems on other examples of my bike (Kh100) as well.

If I were you I would try putting a slightly hotter plug in, BR5ES I would try after checking with your local bike shop / specialist / dealer if this is safe to do so with your bike. If so then see if your problem goes away, I'm guessing your bike is a two stroke here. It's definatly worth checking about wheather its safe to do this first, as you dont want your engine overheating and seizing up on you.

Anyway, give it a go, if its the same problem I had on my bike (sure sounds like it) then this should sort it .

Cheers, Jonathan
____________________
My bike: 1988 Kawasaki KH100 Status: Polluting Devon with two stroke smog and noise pollution!
"Its not your engine size that matters!, It's what you do with it that counts"
Add me to MSN if you want! badlydamaged@hotmail.com.

[Kickstart]

Hi

A B5 is a hell of a lot hotter than a B8. The spark plug removes heat from the combustion chamber. From the NGK web site the difference between one rating and the next is the ability to remove 70~100 degrees of heat, so going from a B8 to a B5 will increase the temperature of the electrode by between 210 and 300 degrees, compared to an operating range for a spark plug of 500 to 850 degrees.

While I might drop from a B8 to a B7 I don't think I would go that far.

Also if the plug is causing the problem then it would probably be from overheating rather than fouling. A hotter plug would make it overheat more.

All the best

Keith
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Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[primalcarl]

What do you suggest I do? And how much of a part does the cdi play? I have a feeling he has used a different cdi on the bike
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Bikes: Honda S-Wing > Honda Varadero XL125V > Yamaha XJ6N > Honda Silverwing> CBR600rr > VFR 800 FI > R1200gs

[badlydamaged]

[Kickstart]

[primalcarl]

I've cleaned the air filter, and fuel tap filter, and adjusted the caburettor to the setting the manual says (but have recorded what it was previously incase I have to change it back).

I just went for a ride and it does the same thing, starts to die. I went down the garage and he said it could be blocked fuel or anything but couldn't say until he looked at it. I don't have £39 an hour at the moment.

Do I risk spending £40 on the proper cdi, or attempt to clean the fuel system & caburettor?
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Bikes: Honda S-Wing > Honda Varadero XL125V > Yamaha XJ6N > Honda Silverwing> CBR600rr > VFR 800 FI > R1200gs

[Kickstart]

Hi

Clean out the carb, fuel tap and check the fuel lines. All quite easy and should not take too long. Worth draining the tank as well. Just make sure you have something to store the petrol in first.

All the best

Keith
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Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[primalcarl]

Today I cleaned the carburettor, and have yet to take the bike out and test it.

Someone emailed me today, this is what he said:

'just an idea mate but have you checked the colour of the oil. sounds to me like coolant is leaking through the water pump into the gear oil causing an overheat. the problem which causes this is the mechanical seal in the water pump hope this helps marc'

Is this plausible? The oil is clear
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Bikes: Honda S-Wing > Honda Varadero XL125V > Yamaha XJ6N > Honda Silverwing> CBR600rr > VFR 800 FI > R1200gs

[primalcarl]

Well the oil was clear last week but today it is more greyer and darker
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Bikes: Honda S-Wing > Honda Varadero XL125V > Yamaha XJ6N > Honda Silverwing> CBR600rr > VFR 800 FI > R1200gs

[Kickstart]

Hi

If the water was leaking into the gearbox oil then the gearbox oil would look like mayonaise.

All the best

Keith
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Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing