[Prodigy]

Hi folks, looking for some ideas on what the problem might be with my thundercat.

The problem is intermittent and shows itself several ways, or perhaps there is more than one problem.

Firstly after a steady cruise at 80mph on the motorway, when I come off the motorway the engine seems to stutter and give less output.

Also there is a situation when idling that the revs seem to go up about 1000rpm and then sometimes settles again, this happens with the throttle fully closed.

Looking forward to hearing peoples theories.

Cheers

[pilninggas]

probably worn-jets/needles.

could also be valve clearances.

[Rich_B]

After a motorway cruise what does your temp gauge say? Mine gets like yours unless I block off radiator with a bit of plywood!

[Prodigy]

Rich_B, on 28 February 2010 - 07:35 PM, said:

After a motorway cruise what does your temp gauge say? Mine gets like yours unless I block off radiator with a bit of plywood!

Temp gauge barely moves on it.

Would you expect worn jets on a bike with 20k on the clock? Valve clearances easy enough to check?

Cheers

[pilninggas]

Prodigy, on 28 February 2010 - 08:39 PM, said:

Temp gauge barely moves on it.

Would you expect worn jets on a bike with 20k on the clock? Valve clearances easy enough to check?

Cheers

the jets may well be worn at that sort of mileage - they go oval as the needle vibrates in the orifice (ooh 'er missus) and ovals the hole making the bike run rich.

Not done the vlaves on a 'cat, but have done em on an exup...usual stuff its the time-hassle of getting to them thats the biggest problem.

of course you could sort both these things and not solve the problem. You might just have to investigate both. For jets/needles google a company called allens.

[Rich_B]

Your bike sounds exactly like mine. . .
Mine has new thermostat and coolant which didn't make a blind bit of difference. My mechanic brother doing my shims as we speak! They're a royal pain if your have no patience. . . like me. I didn't put new plugs in cos I thought they looked ok but now I'm gonna get new plugs and jets to see if that helps matters, Thanks Pilningas

[Prodigy]

Rich_B, on 01 March 2010 - 07:22 PM, said:

Your bike sounds exactly like mine. . .
Mine has new thermostat and coolant which didn't make a blind bit of difference. My mechanic brother doing my shims as we speak! They're a royal pain if your have no patience. . . like me. I didn't put new plugs in cos I thought they looked ok but now I'm gonna get new plugs and jets to see if that helps matters, Thanks Pilningas

Let me know if you find a good deal on jet kit for the bike, I'd be interested to know. cheers

[Rich_B]

It'll be a while, but I'll post here asap

[Prodigy]

Rich_B, on 02 March 2010 - 02:26 PM, said:

It'll be a while, but I'll post here asap

No worries, I'm doing some reasearch and I'll let you know if I find anything. I've not got time or money to address this issue right away.

[Prodigy]

OK, so Allens got back to me and asked me for part numbers of the jets and needles. How easy/difficult is it going to be to get this information? Are the jets and needles a standard fittment for bike and year? If so can anyone point me in the right direction for the info I need to give to Allens.

This is the info they requested: "If you could advise the codes from the needles (located around the top, where the e-clip fits) and also the needles jets (3 digit number, then a letter then a number)"


Cheers

[Rich_B]

You have to take carbs off and take em to bits to look at the jets and needles, which may have been changed from standard to suit an aftermarket exhaust system!

[Prodigy]

Rich_B, on 06 March 2010 - 07:51 AM, said:

You have to take carbs off and take em to bits to look at the jets and needles, which may have been changed from standard to suit an aftermarket exhaust system!

OK, having never taken the carbs off this bike, how long of a job is it likely to be?

Cheers

[Rich_B]

If I was you I'd get a haynes manual and budget for spending at least a day taking carbs off and to bits and then back together again if you use the bike as your only transport.

[Prodigy]

Rich_B, on 08 March 2010 - 08:17 PM, said:

If I was you I'd get a haynes manual and budget for spending at least a day taking carbs off and to bits and then back together again if you use the bike as your only transport.

It can wait until I have the VN800 taxed then I have plenty of time!

[Rich_B]

The latest idea is that the oil cooler might cooling the whole sytem too much. . .

[Prodigy]

Rich_B, on 10 March 2010 - 06:44 PM, said:

The latest idea is that the oil cooler might cooling the whole sytem too much. . .

I thought being water cooled the bike didnt have an oil cooler?

[Rich_B]

Prodigy, on 17 March 2010 - 02:37 PM, said:

I thought being water cooled the bike didnt have an oil cooler?

bit o both. Well a lot of water cooling n a bit of oil.

[Prodigy]

Rich_B, on 18 March 2010 - 09:02 PM, said:

bit o both. Well a lot of water cooling n a bit of oil.

Do we know what the temp guage should rise to on a normal ride? Mine lifts a bit off the bottom but not much.

[Rich_B]

Prodigy, on 18 March 2010 - 11:23 PM, said:

Do we know what the temp guage should rise to on a normal ride? Mine lifts a bit off the bottom but not much.

Nope! I've never seen mine move - other than stood in traffic on a very hot day, then it went to 100 and fan came on. This is only a distant memory though, it's been 3 months since I saw my bike let alone swung a leg over it. Waiting for a new clutch to arrive, now. Shims were ok so not all bad news from my mechanic type brother.

[Prodigy]

Rich_B, on 20 March 2010 - 11:42 AM, said:

Nope! I've never seen mine move - other than stood in traffic on a very hot day, then it went to 100 and fan came on. This is only a distant memory though, it's been 3 months since I saw my bike let alone swung a leg over it. Waiting for a new clutch to arrive, now. Shims were ok so not all bad news from my mechanic type brother.

So your valve clearences checked out OK? What mileage is your bike?

To top all this I think my original downpipes have given up, bike is more noisey than usual, sounds like exhaust, have stainless micron can so I'm going with downpipes, will investigate and report.