1127F engine running hot

[bruteforce]

Ofcourse you need to bring them back to standard mains, single springs and needle height, easy to do. Big box o'spares with different sets of drilled slides so you can try which ones are most  to your liking.

[Jelly]

6 hours ago, bruteforce said:

Ofcourse you need to bring them back to standard mains, single springs and needle height, easy to do. Big box o'spares with different sets of drilled slides so you can try which ones are most  to your liking.

This should do the trick, I thank you  

[Fula28]

Bingo, now have spares too.

[Jelly]

Bit of an update on the progress... Bought the carb's of Bruteforce, and all his spares as he won't be touching them again. As the 34's he was running were modified for turbo usage, removed the double springs and checked other things. Jet was actually a good size compared to my previous setup and the slides were already drilled. The only difference with my previous carbs was that these have 2 fuel feeds, not one as the ones that were on. But this was already connected via a T-piece. Fired the bike up with a test tank (with a simple on/off tap) and it fired up instantly and sounded so much better than before. Happy  

So, fitted the bodywork and the rest to the bike, rolled it outside, fired it up for a testride and... Nothing? It wouldn't start. We quickly found out that the carbs weren't getting any fuel, so vacuum problem? Don't know. Turned the tap to PRI and it didn't solve the issue. So wheeled the bike back in again and pulled it apart. It is strange. Everything seems to be right but the carbs don't pick up their fuel as they should. Solution for now is to transfer all the new bits (needles, tubes, slides, etc) to the old carbs and try again... Grrrr.

[bruteforce]

Wouldn't it be easier to find the fault? How difficult can it be. As this is the best set of carbs of all of them you would go backwards in development.

[badger]

20 minutes ago, bruteforce said:

Wouldn't it be easier to find the fault? How difficult can it be. As this is the best set of carbs of all of them you would go backwards in development.

What he said!
Easy to check. If fuels not getting in it's either gonna be a blocked tap or squiffy floats. Nothing else Really to go wrong!!

[Jelly]

I hear you both. But the issue with the new carbs was so strange that we needed to filter out any errors on the 1st set of carbs. Anyway. Removed all good parts from @bruteforce his carbs. Needle valves, tubes, emulsion tubes, everything that had something to do with fuel. And put them in the 'old' carbs. Result, bike running as shitty as before and not able to hold a steady RPM (yes, they are balanced). 

So that clearly wasn't helping. Went back to the old situation again, the 'new' carbs as they are. But first we've checked the petrol flow as these carbs have 2 fuel feeds and the old ones have only one. No blocking whatsoever. 

As you can see above, the double fuel feed. 

Then fitted them to the bike again, filled with a test on/off loose fuel tank and presto, success. Bike was running very smooth and kept running. Vacuum working, and it was sucking fuel in. Next step, fit the fuel tank again and test the vacuum tap. We let the bike run empty on the fuel hose so we made sure the hoses were empty and we were able to see the fuel flow. Fired it up and it instantly started sucking fuel from the tank and kept running. So that seems to be solved! Test ride will be made tonight to see if it is still running hot, too bad it's so cold outside... 

[Jelly]

16 hours ago, bruteforce said:

Wouldn't it be easier to find the fault? How difficult can it be. As this is the best set of carbs of all of them you would go backwards in development.

It's not difficult, but when things happen which you cannot explain, you look for other options. Both @Rene EFE and I have pulled apart Carburetors more than often and we couldn't tell what was happening here. 

[bruteforce]

9 hours ago, Jelly said:

It's not difficult, but when things happen which you cannot explain, you look for other options. Both @Rene EFE and I have pulled apart Carburetors more than often and we couldn't tell what was happening here. 

You should ask a grownup to help you Jelle! Just kidding guys 

[Jelly]

Aren't we all grownups?  well anyway, it works now, had my testmonkey test it yesterday. Just have to testride it a bit longer to see how the heat problem develops but since we have checked the sump and there are no blockings at all it can be assumed that the carbs were the main problem.

[MeanBean49]

Might be worth looking for a fuel pump off a zxr or somthing in the future, they shut off when carbs are full, just helps to make sure fuel gets there well all the time. Had one on my race bike as it used to be funny when running low fuel loads

[Solcambs]

9 minutes ago, MeanBean49 said:

Might be worth looking for a fuel pump off a zxr or somthing in the future, they shut off when carbs are full, just helps to make sure fuel gets there well all the time. Had one on my race bike as it used to be funny when running low fuel loads

Back in my RG570 days I gave up on the fuel pump we'd fitted as the grosse vales couldn't cope in the RG bored out flatslides. Larger grosse valves helped for a while but were still prone to sticking with the occasional flow of fuel out of the over flows and a pump that wouldn't shut off. In the end I just went with a twin line Pingle tap which solved things for me after I vented the tank.  As with all things, you make a change to solve something and it can add another issue somewhere else!

[bruteforce]

Glad it runs well now Jelle, that was the whole point. Next stop: Donington!