- Wed Aug 13, 2014 10:15 am
#4040
Hello All
A few months ago I purchased a 2002 350 which I am generally very pleased with. It looks great, sounds good on its Hitchcocks free flowing ‘silencer’, and is light and easy to handle which makes a nice change from the generally bigger classics I run. As an experienced restorer and rider of British bikes I had no illusions about the expected performance, notwithstanding I was still disappointed by the effective 50mph cruising speed and approx. 60 mph top end. I therefore embarked on the well trodden path of trying to extract a little extra useable performance.
After trying larger main and pilot jets on the VM 24, and no air filter in the tea caddy, I could not really discern any noticeable increase in oomph. Following this I fitted the one tooth larger front sprocket which again did not really give much increase the top end figures.
I recently fitted a 26mm Mk1 Concentric with the following set-up: throttle slide 3.5, needle mid position, main jet 160, bell mouth with no filter, the pilot jet is a fixed bushing. Although it is early days and opportunities to test and fine tune have been limited recently due to the bad weather and other commitments, early results show some improvements in terms of feeling less strained in the 50-60mph region, and 70mph shown (the speedo seems fairly accurate when compared to those roadside speed signs) with what may have been a following wind and slight decline.
Overall I am disappointed with results; with a Concentric, no air filter, free- flowing silencer and 17t sprocket I would have hoped for maybe a genuine 75mph top end. What results have others achieved with a classic 350 and similar set up? Is a 160 main jet about right with this setup? What increments could be achieved if one goes down the high comp piston, performance cams, gas flowed head route?
At this stage I should say that although I am an experienced restorer and rider of classics of nearly every size and type, and have a great deal of mechanical sympathy and understanding, I am not shy of wringing the throttle on the Enfield and perhaps ride it harder than some would think wise. I am certain however that a well fettled 350 should be able to run up to 70mph with ease and cruise at 60 and not be restricted to sub 55 running. Of course I am not talking about riding down the M6 at 70mph for hours on end...
My gut feeling is that all of the above would in simple terms be better replaced with a 500 and some stage 1 tuning.
I must stress that my bike is apparently in very good condition and throughout all of the above changes has always been well set up and running well i.e. with each change has at all times has been an easy starter hot or cold, with a reliable slow tickover, clean pick up and no popping on the overrun etc. I haven’t had the engine apart however, and I do know that it has in the past had issues with nipping-up due to the ATD mechanism being prevented from advancing by the condenser having been pushed into the CB mounting plate. So it could be that the valves, piston or bore have been slightly damaged by this.
Thoughts and experiences from people who have been through a similar process gratefully received.
A few months ago I purchased a 2002 350 which I am generally very pleased with. It looks great, sounds good on its Hitchcocks free flowing ‘silencer’, and is light and easy to handle which makes a nice change from the generally bigger classics I run. As an experienced restorer and rider of British bikes I had no illusions about the expected performance, notwithstanding I was still disappointed by the effective 50mph cruising speed and approx. 60 mph top end. I therefore embarked on the well trodden path of trying to extract a little extra useable performance.
After trying larger main and pilot jets on the VM 24, and no air filter in the tea caddy, I could not really discern any noticeable increase in oomph. Following this I fitted the one tooth larger front sprocket which again did not really give much increase the top end figures.
I recently fitted a 26mm Mk1 Concentric with the following set-up: throttle slide 3.5, needle mid position, main jet 160, bell mouth with no filter, the pilot jet is a fixed bushing. Although it is early days and opportunities to test and fine tune have been limited recently due to the bad weather and other commitments, early results show some improvements in terms of feeling less strained in the 50-60mph region, and 70mph shown (the speedo seems fairly accurate when compared to those roadside speed signs) with what may have been a following wind and slight decline.
Overall I am disappointed with results; with a Concentric, no air filter, free- flowing silencer and 17t sprocket I would have hoped for maybe a genuine 75mph top end. What results have others achieved with a classic 350 and similar set up? Is a 160 main jet about right with this setup? What increments could be achieved if one goes down the high comp piston, performance cams, gas flowed head route?
At this stage I should say that although I am an experienced restorer and rider of classics of nearly every size and type, and have a great deal of mechanical sympathy and understanding, I am not shy of wringing the throttle on the Enfield and perhaps ride it harder than some would think wise. I am certain however that a well fettled 350 should be able to run up to 70mph with ease and cruise at 60 and not be restricted to sub 55 running. Of course I am not talking about riding down the M6 at 70mph for hours on end...
My gut feeling is that all of the above would in simple terms be better replaced with a 500 and some stage 1 tuning.
I must stress that my bike is apparently in very good condition and throughout all of the above changes has always been well set up and running well i.e. with each change has at all times has been an easy starter hot or cold, with a reliable slow tickover, clean pick up and no popping on the overrun etc. I haven’t had the engine apart however, and I do know that it has in the past had issues with nipping-up due to the ATD mechanism being prevented from advancing by the condenser having been pushed into the CB mounting plate. So it could be that the valves, piston or bore have been slightly damaged by this.
Thoughts and experiences from people who have been through a similar process gratefully received.
