Still fighting with the fuel issue, I wonder if the solenoid is contributing to vapour lock. I shortened the fuel pipe last night and checked the routing, and checked the solenoid. The engine ran fine then after a while idling and checking the tune a few revs etc, the pump started clicking again. The solenoid does get warm to the touch. Could the heat additional heat from the fuel passing thru the solenoid be contributing to vapour lock, I dunno?
While tinkering with the carbs it might be an idea to bypass any non essential items, filters, cut off things etc to just to rule out any effect they may have A
Right, the fuel vapour locking seems better, it's not 100% perfect, but it may have been doing it before and I never noticed, it has been driving fine, even when it was worse, so I assume the lack of fuel flow at idling is exacerbating the problem. I will plan on relocating the fuel pump closer to the tank this winter. Moving on, time for fresh plugs. Any tips and tricks on a type 4 worth knowing about? It can't be as bad as a Type 1 with performance heads and large twin carb manifolds can it? New o-rings for the idle jets ordered, let's see if expensive Eurocarb have sent the correct ones. I did ask them, so I will have a good moan, if they're not correct.
Just be sure your plug socket gets a good grip of the plugs for 2 & 4. There were 3 loose plugs under the tin the first time I removed it from my Westy years ago.
Plugs done. Also did the o-rings on the idle screws. I had another go at tuning her, until my new synchometer broke, so much for made in Germany . It's a bit better, I think, but neither of the above made much difference, I think any improvement was mostly was down to the tuning.
I made an unexpectedly large improvement on my idle the other day. One always lags marginally on the snail scale. I opened it's bypass until it matched the other barrel, about 1/2 turn, then rebalanced. It's smooth. The difference was one read bang on 5 and the other just touching the line so not much to look at. Still pops on overrun of course.
Ey up F pantos, I've been tuning my dells recently , having the same issues as a lot of others do. mine was rich at cruise, put smaller idles in ,smaller mains etc I got it to cruise with out bucking today, and have seen the AFR gauge lean out at cruise when I UPPED the AIR jet. 55 idle 160 main 36 vent 48 pump .2 e tube. Well I started with the smallest air jet I had. A 160 with a 0.8 stainless wire effectively making it a 0.8 air jet. So with the above jetting the symptom on my motor is rich at low speed cruise with bucking thus needing a gear down shift. So I have removed the 0.8 wire to introduce some air to it , putting the air jet back to a 160. The richness at cruise has leaned out to the point were the low speed bucking has gone almost. So if you up the air jet size further it will lean out the cruise AFR to the point were the engine dies when trying to accelerate . I tried this with a 180 air drilled out to a 300 (3 mm) the motor just died .Yeah my motor isn't like yours or anyone else for that matter but it does prove that it works .
We had a quick session at TE. After a lot of messing around we realised the arms on the CB Performance hex bar linkage actually hit the air cleaner bases when the adjustable rod going down to the throttle on the carbs is mostly vertical. And what that does is encourage the ends of the bar to have oval holes in them rather than circular ones. So the whole linkage rocks around, sliding diagonally forwards and up as the tension of the springs on the spindles pushes against the push down from the bar. Making synchronising the operation of two carburettors unlikely as it depends on the balance of forces and friction ,with many different equilibrium points for the same pedal positions. The basic effect was that the left hand carb often shut off well before the right hand one. And the dynamic balance of the two carbs was all over the place. Not that we had a snail gauge , it was so far out you could see it. So the compromise was to get them both to shut at the same time, then adjust the mixture leaner on the LH carb which had been richened up to the point it was backfiring at me while I was listening to it...
Ideally the arm on the carb would be at about 45 degrees to the throttle plate so that at half throttle the arm is horizontal or a little below. Pretty bad design if that clash can't be adjusted out!
