Loss of top end power

[K@rlos]

Normally I'd go see my mate who built my motor but sadly he is laid up in bed a chest infection, poor Hector

Right: got a 2110, FK 8, twin 48 IDF's and DRD L5 heads with an 009 dizzy. Problem is, normally the motor pulls hard from idle right round to 6500 rpm and even when sitting at 70mph (4000 rpm) if I floor it, it will comfortably pull round to 6500. At the moment however it pulls hard through the gears but if I plant it at 70 it doesn't seem to wanna know. :? Motor starts, idles and cruises around fine it's just the higher revs it seems in happy with. First thought was cam had gone flat but it would have the bottom end, so I'm wondering if the carbs are full of **** or the timings moved? Cleaned jets, plugs checked valve lash and carb sync.

Any ideas?

Cheers

 

[Hadders]

I had siimilar a few weeks back - Mine's a 1955 with dellorto 40s, but similar symptoms, idled fine, sat at speed fine but wouldn't accelerate cleanly. Ruled out timing since its all electronic - turned out that there was ***** in the carb, the jets on one side weren't clear and diaphragm was replaced (although it looked fine)

Ran better after cleaning the jets but the new diaphragm seemed to be the thing that sorted it

500 miles later, after a 'run' to the gower and all is good

 

[K@rlos]

I must confess didn't think to check the diaphragms, they were changed 2 months ago it's quite possible. It is as if the engine is being starved of fuel.

 

[Hadders]

That's exactly what I had, really hard to replicate as well unless driving

We didn't plan to change either, the engine had only done a couple of thousand miles total, but it seems to have sorted it

Hope you get it sorted, sounds like it goes well when it's on song 8)

 

[sparkywig]

I've got the same problem. :|
Fine in all gears up to about 4k, then nothing.

 

[K@rlos]

That's exactly what I had, really hard to replicate as well unless driving

We didn't plan to change either, the engine had only done a couple of thousand miles total, but it seems to have sorted it

Hope you get it sorted, sounds like it goes well when it's on song 8)

It is rather brisk to say the least :lol: cheers for your help, hopefully I'll end having the same problem as you.

 

[K@rlos]

I've got the same problem. :|
Fine in all gears up to about 4k, then nothing.

Reckon we both have carb trouble Si, doubt both our motors have **** them selves haha

 

[Alex VW Heritage]

quick fix try would be rev it to 2000rpm and jam you hand over the top of the carb it will suck hard and hopefully draw the crap out of the jets

 

[K@rlos]

quick fix try would be rev it to 2000rpm and jam you hand over the top of the carb it will suck hard and hopefully draw the crap out of the jets

Tried that, had all the jets out and cleaned them too. Ordered some pump diaphragms today, will try them. Taking it over Hectors Friday, sure he'll sort it if I can't.

 

[Graham L]

Had the same with my Dell 36's recently, I'm sure the floats were sticking, took the top of both carbs, cleaned the crap out with an airline and made sure the floats moved OK, second time this has happened with my dells.

Pict 34's are much easier

 

[K@rlos]

I've stripped the carbs down and cleaned them out and now it seems a lot better. Still needs a good tune in IMO. Gonna get it on a rolling road I think.