NGneer wrote:I am sure you won't have to worry Mitch.

Rick is a busy guy but is a top Bannana and is always very prompt with his stuff...and as you will see the quality is always tip top.

Digging into your bike the first time is a little daunting, but the absence of a milion computers or other electronics means that with a haynes, a half decent tool box and some patience, very little is actually beyond the capabilities of most of us

I can see from Ricks reputation I have nowt to worry about. I'm just being impatient as I want it all back in one piece ASAP! lol.

Yeah it's definitely daunting stripping the bike for the first time but I've thoroughly enjoyed it and would be confident in doing it again in half the time.

Also having learned this lesson with previous bike and cars, no matter how mint it looks on the outside, there's always a few hidden horrors esp as this bike is 25 years old. I feel I've been lucky though as so far it's only been butchered carb screws, melted and unnecessary fuel filter and the ignition barrel horror! See pic. No wonder the ignition lights were flickering! I don't know why it was soldered at all but it is a mess to say the least.

That is some shit soldering.

Hi guys. Got my bits from Rick today. Very quick service. Many thanks Rick.

Updates from today are a bit disappointing. Got the bike back together with carbs cleaned, valve clearances checked, inline fuel filter removed, new HT leads. Only thing I'm waiting on is plugs.

Got the bike started. Still running on 3 and lumpy idle. Exactly the same as before. Swapped plug from a good cylinder and he problem remained on the same cylinder. I checked spark and it is fine with any plug. Same spark as the others.

I can't do a compression test as no one has adaptors for the 8mm plugs. What's next to check guys? When I did the carbs I cleaned the jets and the float chambers. Is there anything else I missed from the carbs that could be causing the problem?

Has anyone got an adaptor to sell or lend or a link to a place that sells them?

Thanks guys,

Mitch.

Did you check float heights, idle mix screw setting, as well as that choke is opening and closing properly. And assume you cleaned the idle jets as well? I recently had a similar problem that was a combination of all of the above...how does it run pask 7000rpm? Ie on main jets?

Alternatively it's not a fuel problem is it?

Icemaestro wrote:Did you check float heights, idle mix screw setting, as well as that choke is opening and closing properly. And assume you cleaned the idle jets as well? I recently had a similar problem that was a combination of all of the above...how does it run pask 7000rpm? Ie on main jets?

Hi thanks for the reply.

Is the idle jet the pilot jet? If so yes it's all been cleaned. Idle mixture screws all set 2.25 turns from fully in. Choke is working fine. The carbs were pretty spotless when I removed them tbh. Still feels gutless above 7k rpm. I need it fixed pronto doh!!

Does it chime in when revved or is it just bad at low revs.
Remove jets and pilot screws and blow all airways from both directions [backwards first] with compressed air.

If it ran well when last used, unlikely a compression problem, and that normally shows up at low revs.

Try one of these to compare compressions on each cylinder.
The rubber will need cutting smaller for the small plug holes, or fit a smaller rubber bung.

The last person I loaned the Gunson to had a problem with the Schrader valve, so best avoid that type perhaps.

Hi,

The reason I've stripped it was because it was running on 3. I think that one cylinder has given up completely. =(

If I turn the bike over with plug removed should fuel vapour shoot out?

Where can I get one of those compression testers?

Maybe the emulsion tubes need cleaning too? I'd quickly check that fuel is coming out of the tank nicely - does sound a little like when it starts to run outa gas :-)

More likely carb than compression, but lots of testers on e bay, but with brass adapters [not nc size] but with 2 rod/rubber bung adapters included.

Put the bike in first gear with only the bad cylinder plug fitted.
Turn the back wheel, and compare the engine resistance/compression with just one of the 3 good cylinders with a plug fitted.
You could turn the engine with a torque wrench on the rear wheel nut to be more accurate, but the first way will soon show if there is any compression.
Don't put it in top gear, the engine will turn over too easily.