Project: Garage Find

[squirrel_hunter]

It does fire I had it running, though briefly with blocked pilot jets so that should rule out a timing issue.

I'm also running on premix still. There is some old 2 stroke oil coming through the pipes. Its at the right intake now but not the left.

[squirrel_hunter]

So I've spent most of the week trying to start the bike. My shin is not a pretty sight. But no dice. So had a quick word with one of the mechanics at Artdeans who suggested a couple of little things. The first was that it just needed the reeds wetting, an introduction to starting if you will. And to assist with the introductions, some carb cleaner straight down the intakes.

With a squirt of carb cleaner the bike fired into life on the first kick. But then died off quite quickly. It was burning through the carb cleaner but not taking any petrol in.

So the next thing to try was to cover the air intake to force it to suck through. Carb cleaner to get it started and then hand over the carb and it starting running up. The more I did this the longer it would run for so much so that I began trying to set the idle. But the results were very erratic.

Something is still not right. It dies off a little to quickly and isn't really settling down. The strangest thing is that if I cover the intake on either side the revs shoot up to around 7k and starts to climb higher but I don't fancy letting it redline yet so am knocking it off early.

It is running off the petrol/ oil premix and the oil from the pump (there is still some of the old oil coming through. But it is just gargling to an end unless I prevent air getting into carb which is then allowing it to smoke up more.

So has anyone else got some ideas of what to try and play with?

Also has anyone got any base settings for the idle? Turns out from fully in would be good. I can just fine tune from there, but at the moment I have do idea how far out I am and if it just needs a little fine tuning and running.

Blocked pilot jets! Simples! need to get some electrical wire, strip off the insulation and use one strand of copper wire down the pilots. Or steep them in carb cleaner.

c

More thoughts : If it picks up and revs when it is short of air (ie when you cover the air intake) is it running weak? too much air to fuel mix...

Know you have cleaned the carbs to death but is there any chance that between the fuel bowls and the pilot jets there is an obstruction? New jets are in but is there any fuel getting to them?

Going to lie down in a dark room and have a think...

Your description is definitely pointing to pilots. The small secondary jets in the float bowl and the small venturi running to them. They control the engine running at idle. If its running and taking off when you open the throttle you are then coming off the pilots and onto the needle and main jet.

There should be standard cab settings online and if I remember my RD350 settings the mixture screw was 2.5 turns out from closed. As a rule of thumb the bike should start and run with the screws out half of their setting range and then back in half a turn.

C

[squirrel_hunter]

The pilots are new and I did blast everything out with the compressor before assembly. I'm not ruling it out but I would be surprised if there is something in there.

As for the question of fuel getting through my hand gets wet with fuel when blocking it off. And this is also with nothing on the throttle. So it looks like it is getting through the pilots but I can't be sure. When it tries to settle it dies off, but then its reving to high in the first place.

To add some more detail on the adjustments I have on the carbs, I can alter the idle speed, I can change the needle height, I can alter the float height. Anything like jetting would require new parts. All parts are at standard, the pilots for example. And all heights are standard. There is no mixture screw on these carbs, unless that has another name that I don't know.

Martin77 (not of this parish) who made the awesome sounding pipes suggests an air leak. And I can see why if I block off the air it runs better suggesting to much is getting in. So suggestions on how to pin a leak down would be good if anyone has any? Also he asked about the vacuum pipe... There is on the left carb an additional pipe that goes to the fuel tap if memory serves. As I'm running from a remote tank this is not connected to anything. Should I block this off or leave it open?

[squirrel_hunter]

One bit of promising news however is that while I did have it running I decided to knock it into gear, and... The sidestand cut out switch works.

Also if I have it running with the sidestand up and then I put it into gear gently letting the clutch out gives me some forward momentum. This indicates that I have at least 1 gear in the correct direction.

[Bibio]

have you checked to make sure that the sparks are sparking at the right time for the right cylinder?

your timing could be out by 180. try swapping the leads of the coils.

[Doinitmyway]

Originally Posted by squirrel_hunter

The pilots are new and I did blast everything out with the compressor before assembly. I'm not ruling it out but I would be surprised if there is something in there....

Martin77 (not of this parish) who made the awesome sounding pipes suggests an air leak. And I can see why if I block off the air it runs better suggesting to much is getting in. So suggestions on how to pin a leak down would be good if anyone has any? Also he asked about the vacuum pipe... There is on the left carb an additional pipe that goes to the fuel tap if memory serves. As I'm running from a remote tank this is not connected to anything. Should I block this off or leave it open?

I would say that additional pipe is for the vacuum diaphragm on the tap so that fuel only normally flows to the carbs when the engine is running. Check on the fuel tap for a similar take off. Definitely put a pipe on it and block it!


Can the carb slides be put in the wrong way round on these?? Sometimes the older carbs with the round slides would have them put in 180 degrees out. There was a cut out in the slide body that should have faced the airbox side of the carb. Just a thought!?!


Chris

[squirrel_hunter]

To answer a couple of suggestions the plugs are timed correctly as its not possible to swap the leads round as there is one coil pack mounted on the right of the frame. So the leads can only reach their correct plug, and I've not swapped the leads from the coil pack.

The other suggestion of the carb slides being the wrong way round can be ruled out. Its not possible to put the slide in round the wrong way due to the design it only goes in one way. Ask me how I discovered this...

Good news however I think Martin77 (not of this parish) got there first with the vacuum pipe suggestion. Also had a chat with Dave from Artdeans who confirmed this was defiantly something that needed looking at and gave me a couple of additional pointers if that didn't yield positive results. But it did!

Blocked the pipe off and kicked it over. Was a little hesitant at first and needed some blocking of the right carb initially but after a couple of seconds the revs though high were stable. And so out came the screw driver and the idle adjustment.

After a few minutes I had the bike ticking over at about 1,800 rpm. Its still smoking a fair bit as its on the premix as well as the pump but better to be safe. Might start reducing the amount of oil in the premix.

Need to get the air box back on and hopefully the starting will be better, hopefully it was just needing the introduction to starting. I had it ticking over for a few minutes plus a few start stops, with it starting on the first kick.

Also can confirm the temperature sensor is working.