Project: Garage Find

[squirrel_hunter]

Good news I think Martin77 got it 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.

[squirrel_hunter]

Umm... Its still not perfect. Starting needs either carb blocked off with or without the choke. Needs a bit off warming up before its stable as well.

From what I've learned with the vacuum pipe, it suggests an air leak? But everything feels tight and I can't feel any drag like I get blocking the intake. Worse case is crank seals, but I hope its going to be something simpler. Trouble is I'm not sure where best to start looking and how best to locate the air leak?

[Martin77]

Have you tried it with the airbox in place? does the choke make much differance? (just wondering if the choke jets are still blocked)

[squirrel_hunter]

Yes didn't make that clear, airbox is now on with a new oiled filter in. Choke on or off no difference in starting. I did blast them with air and the choke plungers are new.

[stevewr250]

I had a similar problem on my 3xv but only on one cyclinder after a hundred carb removals i removed the reed block as i had fitted a new gasket but dry, so i gave the reed block gasket's a smear ot threebond sealer and i had a great improvement so i must have had an air leak in the gasket.
This did not cure my carb problems but it was a major improvement.
I know how you are feeling after the pure joy of final assembly it brings you down to earth with a bang when you get teething problems but take it bit by bit actually it is good practice, now i can take carbs off blindfold and in minutes.hope this helps and good luck.
Steve

[squirrel_hunter]

Yep taking those carbs on an off is a 2 minute job. But I am starting to think that I might take the instant gasket route as its a fair assumption that its an air leak and the reed block is a good possibility. But it does seam like a bit of a hack. Any other ideas or suggestions out there?

[Mick]

Warm the bike up so its able to idle then spray around the intake area with WD40 and see if engine RPMs are affected...

[stevewr250]

Hi it mite be a pain in the ass but i'm afraid them carb will be coming off and stripped a lot's more times before you get to the bottom of it so may as well get it done 

[squirrel_hunter]

Time was spent in the garage today putting into place some of the suggestions that I have been given from here and other places and sources.



The first thing to do was to locate my new fuel tap. The original I didn't even bother with trying to reuse after seeing what came out of the tank and the carbs. Thankfully I didn't pay Yamaha for it, managed to grab a bargain less then the cost of a refurbishment kit.



Mounted it on the bike to take over duties from the bolt that is plugging the vacuum hose by connecting it how it should be when fully assembled. I am however still running premix from the remote tank.

Next I took the carbs, the intake rubbers, and the reed blocks off. Then put them back on this time with a small smear of instant gasket on the mating faces. And I really do mean a smear, not a bead of gasket. Simply wiped some on with my finger, just enough to plug any little gaps but not overspill.

Torqued that little lot up and went to work on the carbs while that dried. Both carbs were again stripped down and blasted with air. Paid some extra attention to where the choke plungers sit but didn't see anything untoward.

But on reassembling the carbs I was also advised to check the float heights again. The right was fine but the left was out. Odd. I checked the float heights each time I rebuilt the carbs and each time they were both within the tolerances so can't explain why this time I found the float out. Bit of trial and error to get the height set and then put them all back together.

So with everything reassembled I gave it two kicks without the ignition on with a throttle blip to hopefully get the fuel circulated and ready. Then with the ignition and choke on the bike fired up first kick.

And now a video...



Still need to fine tune the idle once its warmed properly but it looks a lot more promising. There is lot remaining to do such as sort the leaking water pump gasket, and the clutch gasket as I cant tell for sure if its leaking. Ensure the oil pump is setup correctly so I can take it off of premix. Repaint the right exhaust (for the 3rd time). And do a load of other things.

Some extra good news is that I also have second gear, and I rode it back up onto the workbench!

[stevewr250]

Great news. Keep it up the summer is coming

[m3-paul]

Out of interest, what height did you set your floats to? I set mine to 17mm but was interested what others set them at.

Think I will also try and get a new fuel tap and remove and replace the intake rubbers and gaskets. Getting similar symptoms to what you had and I know that my carbs are spotless.

[Mick]

Out of interest, what height did you set your floats to? I set mine to 17mm but was interested what others set them at.

Think I will also try and get a new fuel tap and remove and replace the intake rubbers and gaskets. Getting similar symptoms to what you had and I know that my carbs are spotless.

From memory it's 15 to 17mm on a 2MA however on a 1KT it's a whole different kettle of fish as the floats are round and not rectangular as on 2MA.Though frustrating trial and error(carbs on/off all time)21mm was about right height for them..

[squirrel_hunter]

The manual states that it is 15-17mm is the float height as measured from the top of the float nearest the pivot. I have mine set to around 17mm a tad on the generous side. But it looks like its worked. Not sure if its the best setting, some road testing might be in order soon...

[squirrel_hunter]

So problem solving has been in order. Changed the water pump gasket. I drained the system, disconnected the hose, and then removed the cover. New gasket, reattach everything and fill the system. The following day I find the pump cover leaking worse then before.

Stage 2 of the fix was to drain the coolant and remove the clutch cover. Well I think that the cover was leaking so I need to play with that as well.



Drained the oil and coolant while the bike was on the paddock stand. Then popped it on the side stand to hopefully stop any extra oil dripping off. Wasn't perfect put it think it helped somewhat.

Replaced the clutch cover gasket. Used the same one as before, but noticed that there is something not quite right, and it was the same on the old one. But when I put the original on it appeared to go on fine. This time I thought I'd just trim the bolt holes. And while the gasket drops a little below the cover its not obvious and it seals fine. I wasn't sure that it was leaking it was more of a weep but now I can't find anything to worry about.



I reused the water pump cover gasket, but this time as with the reed block gaskets I used a little instant gasket. Let it dry overnight and then filled the system. So far I have found no leaks.

Also been painting the exhaust again so that is just drying now. I have also ordered some bolts for the fairings and plan to book an MOT next week...

[m3-paul]

The manual states that it is 15-17mm is the float height as measured from the top of the float nearest the pivot. I have mine set to around 17mm a tad on the generous side. But it looks like its worked. Not sure if its the best setting, some road testing might be in order soon...

Thanks for that. Mine is set at 17mm. My problem is I think an air leak on the inlet rubbers. Sprayed carb cleaner around the carb rubbers when trying to start the bike from cold and it fired immediately. New rubbers going on today as the old ones have age related cracks it would seem and pulling in too much air to allow starting from cold.

Regarding your clutch cover weeping, had the same when I used a brand new yamaha gasket and torqued up perfectly to workshop manual spec. I found I had to nip it up a little more than the manual stated to get a perfect seal