Running out of ideas.

jas328sport · Post by **jas328sport** » Fri Jun 15, 2018 7:55 pm

I was bored this afternoon so decided to have the carbs off again and did find a couple of problems. Whilst I had cleaned the carbs out last time I didn't take the floats out, when I removed them this time there was loads of crap under them so cleaned them properly this time but I did find a seal under one of the jet holders that hadn't been fitted correctly and was partially blocking one of the holes as you could see from the shape of the seal that part of it had been forced into a hole. I am still not convinced that this is a actually the cause of my missing as it must have always been like it.
I also checked the diaphrams properly and they are in perfect condition. I am going to order a new seal kit but I also need a new pilot screw as one of them has chewed up so I will need to try and remove it with a screw extractor as I can't set it as it is.
Does anyone have a link for a new pilot screw or have a spare they don't need.

jas328sport · Post by **jas328sport** » Sat Jun 16, 2018 11:49 am

I think I should have just stayed in bed this morning

I decided it was time to try and remove the seized pilot screw as I have a new one on the way. I thought a small easy out would work best so drilled a small pilot hole without any problem as they are so soft, then started to screw in the easy out which seemed to grip lovely, as soon as I started to exert any pressure I heard a crack and the part of the carb housing containing the threads broke clean off

So that's it, game over and a new set of carbs now required, I just wish I had left the sodding thing alone.

YAMAEXUP · Post by **YAMAEXUP** » Sat Jun 16, 2018 9:16 pm

While you're waiting for some replacement carbs, have the inlet manifolds off & check the seals. I've seen these go on old engines & when I checked my ones several thousand miles ago they'd gone hard

https://www.fowlersparts.co.uk/parts/40 ... 9-c/intake

Part 9 on the fiche

jas328sport · Post by **jas328sport** » Sat Jun 16, 2018 9:28 pm

Thanks for the tip, I'll check them out tomorrow seeing as it's already in bits anyway.

jas328sport · Post by **jas328sport** » Sat Jun 23, 2018 1:43 am

Is there a specific torque setting for the inlet manifolds as when I took mine off to replace the o-rings they were very tight so I just did them up murder tight again, i was just thinking that if they were not supposed to be that tight then perhaps over tightening could have caused them to bow in the center.

jas328sport · Post by **jas328sport** » Mon Jun 25, 2018 3:43 pm

Finally getting somewhere. Took the intake manifolds off again and cleaned up the faces with wet and dry, refitted and just nipped them up. Now the idle settles instantly and sounds smooth at 1000 revs and it no longer cuts out at all when riding.
It isn't completely sorted though as now on very small throttle openings it is only running on 3 cylinders, you can actually hear it running on 3 as you gently open the throttle even when standing still, as soon as you open the throttle a bit more then it runs sweetly.
Going to have one more go at setting the float level as I just read about having the bowl screwed on at the bottom to hold the float holder in position which I didn't do before so maybe they aren't set as well as I thought. Then one more go at balancing and I am done with it.

Teego · Post by **Teego** » Mon Jun 25, 2018 3:48 pm

jas328sport wrote:Finally getting somewhere. Took the intake manifolds off again and cleaned up the faces with wet and dry, refitted and just nipped them up. Now the idle settles instantly and sounds smooth at 1000 revs and it no longer cuts out at all when riding.
It isn't completely sorted though as now on very small throttle openings it is only running on 3 cylinders, you can actually hear it running on 3 as you gently open the throttle even when standing still, as soon as you open the throttle a bit more then it runs sweetly.
Going to have one more go at setting the float level as I just read about having the bowl screwed on at the bottom to hold the float holder in position which I didn't do before so maybe they aren't set as well as I thought. Then one more go at balancing and I am done with it.

Just check your pilot screws first. I once had this syndrome and found one was missing completely.

jas328sport · Post by **jas328sport** » Mon Jun 25, 2018 4:08 pm

Teego wrote:
jas328sport wrote:Finally getting somewhere. Took the intake manifolds off again and cleaned up the faces with wet and dry, refitted and just nipped them up. Now the idle settles instantly and sounds smooth at 1000 revs and it no longer cuts out at all when riding.
It isn't completely sorted though as now on very small throttle openings it is only running on 3 cylinders, you can actually hear it running on 3 as you gently open the throttle even when standing still, as soon as you open the throttle a bit more then it runs sweetly.
Going to have one more go at setting the float level as I just read about having the bowl screwed on at the bottom to hold the float holder in position which I didn't do before so maybe they aren't set as well as I thought. Then one more go at balancing and I am done with it.
Just check your pilot screws first. I once had this syndrome and found one was missing completely.

It's ok as I have had them all out to clean them and check that all of the o-rings were in place, all seemed well and set to 2.5 turns out.

jas328sport · Post by **jas328sport** » Mon Jun 25, 2018 8:37 pm

Well I made sure that the float level was bang on 14mm and tbh it made absolutely no difference. I then decided to try opening the pilot screws a quarter of a turn at a time and when it got to 3.25 turns it seemed to run bang on, I went for a ride and it ran perfectly for about 5 miles before starting to run on 3 cylinders, then 2 cylinders until finally dying altogether as I pulled into home and wouldn't start again so I assume it was flooded.
I screwed the pilot screws back in a half turn and it eventually restarted but needed the choke on until it cleared and then it sounded OK, went for a ride and managed about 8 miles and it didn't miss a beat so hopefully I have cracked it.
Now I just have the fork seals to do as one of them is literally pouring oil out. So my next question lol is how do I support the bike whilst I remove the forks.

Teego · Post by **Teego** » Mon Jun 25, 2018 9:05 pm

jas328sport wrote:Well I made sure that the float level was bang on 14mm and tbh it made absolutely no difference. I then decided to try opening the pilot screws a quarter of a turn at a time and when it got to 3.25 turns it seemed to run bang on, I went for a ride and it ran perfectly for about 5 miles before starting to run on 3 cylinders, then 2 cylinders until finally dying altogether as I pulled into home and wouldn't start again so I assume it was flooded.
I screwed the pilot screws back in a half turn and it eventually restarted but needed the choke on until it cleared and then it sounded OK, went for a ride and managed about 8 miles and it didn't miss a beat so hopefully I have cracked it.
Now I just have the fork seals to do as one of them is literally pouring oil out. So my next question lol is how do I support the bike whilst I remove the forks.

OK, so you have a paddock stand for the rear but not the front.
Fairing lowers have to come off.
Now, best solution is a trolley jack with a block of wood under the headers.
If you don't have a jack I recommend my proven method.
1. Fairings off.
2. Get a wedge under the front wheel to get it max off the ground. An upturned shovel will do if you don't have anything else. Lift the front end by lifting the wheel, the slide/kick the shovel under the wheel until you have max lift.
3. Use whatever is handy to support the bike under the headers.
Oh, there is 1a: crack but don't loosen the axle, brake, mudguard, triple clamp, etc bolts before you lift the bike. That way you will avoid knocking it off the stand while you wrestle with siezed bolts.
It's all quite easy really.

jas328sport · Post by **jas328sport** » Mon Jun 25, 2018 9:35 pm

Yes I have a rear paddock stand and I also have a decent trolley jack with a rubber disc that I use when I need to jack up my motor. I wasn't aware that the exhaust was up to supporting the weight of the bike so that sounds easy enough, thank you.

jas328sport · Post by **jas328sport** » Wed Jun 27, 2018 3:30 pm

Well the forks are now at the shop for their seal change, let's hope my jack holds out

oldskoolexup · Post by **oldskoolexup** » Wed Jun 27, 2018 3:41 pm

jas328sport wrote:
Well the forks are now at the shop for their seal change, let's hope my jack holds out

Am I the only one who thinks that's brave!?

jas328sport · Post by **jas328sport** » Wed Jun 27, 2018 3:43 pm

oldskoolexup wrote:
jas328sport wrote:
Well the forks are now at the shop for their seal change, let's hope my jack holds out
Am I the only one who thinks that's brave!?

Brave or completely nuts

oldskoolexup · Post by **oldskoolexup** » Wed Jun 27, 2018 3:47 pm

jas328sport wrote:
oldskoolexup wrote:
jas328sport wrote:
Well the forks are now at the shop for their seal change, let's hope my jack holds out
Am I the only one who thinks that's brave!?
Brave or completely nuts

Did you fancy fitting your own seals?