Starting to get grumpy

nismo · Post by **nismo** » Wed May 03, 2017 4:51 pm

Well, given my phobia of carbs I think the cunning plan will be to do the carb rubber test first as suggested, if that's the problem then great, easy to fix without the risk of taking things apart. If it's not that, then spray a fuck bucket (it is a unit of measurement

) down the intakes and see if that clears it. If not, then take apart, photograph everything, clean and hopefully put it back together correctly. If that fails, get drunk and kick the cat

yo4hgx · Post by **yo4hgx** » Fri May 05, 2017 1:12 pm

I couldn't get a nice and steady idle and also a smooth <3K rpm transition until I grinded the jet holder. Replacing the gasket would have probably done it too... but didn't find it separately. Think worth checking...

nismo · Post by **nismo** » Sat May 06, 2017 7:25 pm

I am seriously about to loose my shit with this bike. Carbs off, stripped, cleaned (looked like a bit of crap in the pilot jet on carb #3) might have been the problem. Trying to put it back together and now the fucking throttle is sticking. Only when the cable goes back in the the holder, out of it and it is fine

Post by **nugget** » Sat May 06, 2017 8:37 pm

The only thing I can think of is, did you thread the cables through the cards the same way as they came out? Plus are the cables in the grooves of the carb pulley wheels correctly?

nismo · Post by **nismo** » Sat May 06, 2017 9:32 pm

Yeah, everything was routed fine. Changed the adjustment down to the loosest setting (not what it was at when I took it apart) and that seems to have done it. Bike is back together, just fairings to go back on in the morning and see if it has worked

Post by **nugget** » Sat May 06, 2017 10:08 pm

Fingers crossed nismo.

nismo · Post by **nismo** » Sun May 07, 2017 10:47 am

Cheers Nuggitt. It feels better on the stand, but still not perfect. Going to take it out for a little blast, see if it is cured or not. Think if I don't come back with a big grin on my face then it is up for sale. Completely had enough of it now, if it's not fixed by now then it is outside of what I know how to do.

Post by **nugget** » Sun May 07, 2017 11:34 am

It's a pity you don't live nearer to me.

nismo · Post by **nismo** » Sun May 07, 2017 1:11 pm

Status update. Sub 3,000 rpm still got problems, though not all the time, just most of the time. Mid range fine and top end absolutely phenomenal. Cracked the throttle open in first coming out of the town centre and the front wheel lifted. Caught me off guard a bit as I've not known the thunderace lift purely off the throttle. So back to being completely confused.

Teego · Post by **Teego** » Sun May 07, 2017 3:51 pm

nismo wrote:Status update. Sub 3,000 rpm still got problems, though not all the time, just most of the time. Mid range fine and top end absolutely phenomenal. Cracked the throttle open in first coming out of the town centre and the front wheel lifted. Caught me off guard a bit as I've not known the thunderace lift purely off the throttle. So back to being completely confused.

Does it bog down off the line - feel like running rich below 3k. If so, could be toobs. How does it start and idle?

nismo · Post by **nismo** » Sun May 07, 2017 11:03 pm

Sounds like it is running on 3 cylinders at low revs. Starts ok now I've cleaned the carbs, ticks over ok until it gets warm, then the revs start to drop and she dies.

Are the emulsion tubes the tubes above the pilot jets? Little brass ones with holes in the side? Gave them a good blast through but don't know how to tell if they need replacing

nismo · Post by **nismo** » Mon May 08, 2017 6:16 am

Sorry, realized that that was one of the worst problem definitions ever

so here goes on attempt #2

Going to the bike now, with it absolutely stone cold.....

Full choke, starts no probs. Not quite as instantaneous as it used to be, but starts quickly and runs. May be firing on 3 or 4 cylinders at tickover, but blip the throttle and it is definitely 3. Revs will build as it warms, although never gets to the 3500 rpm mark that it used to with full choke. Also noticed that with the exhauat gases can be far hotter than what you'd expect, but not sure if that is when it is running on 3 or with the choke on, or both. Running normally, exhaust gas temperature is normal.

As it warms up, reduce the choke until it is off, and will happily sit at just over 1000 rpm for a few mins, then the revs slowly start to drop until the engine cuts out.

On the road, very rough tickover, sounds like it's running on 3 and have to keep the revs up. Like riding a 2 stroke. Pulling away, still sounds and feels like it is running on 3 until around 3000 rpm when it clears up and the bike takes off like a scalded cat.

Strangley, did a couple of motorway miles in 3rd to get the revs up and keep them there - higher fuel and air flow might unblock something? Anyway came off at the next junction, stopped at the roundabout and everything was perfect. Tick over perfect, engine was smooth and pulled away cleanly. By the time that I hit the second set of lights on the roundabout it was back to firing on 3.

As a bit of background, I ran her minus the airbox before taking the carbs apart - no difference, but I put my hand over each carb intake one after another. Cylinders 1, 2 and 4 when covered killed the engine. #3 made no difference, so that is deffo the problem one

Post by **Stig** » Mon May 08, 2017 9:24 am

Still think it's the pilot circuit on #3

Symptoms are same as what I was having

Expecting issues with mine when I eventually drag it out it's bag

nismo · Post by **nismo** » Mon May 08, 2017 9:39 am

Pilot jets have been taken out, blasted through with carb cleaner and put back in. Not touched the screws yet so they could still be the problem. Is this something that I can fix myself? Still worth looking at the tubes, cos I'm having a hell of a time trying to find new ones

Jay762 · Post by **Jay762** » Mon May 08, 2017 11:27 am

nismo wrote:
Are the emulsion tubes the tubes above the pilot jets? Little brass ones with holes in the side? Gave them a good blast through but don't know how to tell if they need replacing

The emulsion tubes are the ones the needle goes into - where the fuel gets drawn up through into the main body of the carb