Honda-SOHC

Ooooooooo shiney! Mine has more 'patina' 

Agree with you Re the Motad but beggars cant be choosers! To be honest although it might be more efficient I always think a 4 - 1 makes it look like something has fallen off the nearside of the bike!

I am afraid I binned the MOTAD instructions so can't confirm but I THINK the numbering was more about where the tube fits into the collector.

Hi Mike,

When you had the top end overhaul did the barrels come off too? just wondering if its a partial blockage lower in the barrels, such blockages are frequently gasket goo etc and hard to remove without stripping the motor. Using wire might damage something and cause swarf by scratching the alloy and make matters worse. Could also just poke a blockage further down till it lodges in a corner somewhere.

Also have you checked the oil pump, pump screen and oil filter? If oil pressure is low it could be there is only sufficient 'oomph' to supply thicker oils to the 'easiest' side. Agree partial blockage is more likely tho.

Could also be a missing / malfitted head O ring, so rather than oil not getting through due to blockage it could be leaking pressure.

If you don't fancy a head and barrel strip only other suggestion I can think of is to pump more diesel through and leave it for a bit, it might dissolve a blockage ( but this is unlikely if its gasket goo. )

Your plan of sequential strip and check sounds good to me, but you just may have to strip further than you had hoped. I hope not but be prepared.

Came a bit late to this but I too had a couple of issues when fitting a Motad 4 into 1 to my F1. I did feedback at the time but for completeness!!

Firstly I couldn't make the thing fit at all. Naturally assumed the problem was with the nut trying to fit the system! turned out 1 header pipe was the wrong one! Motad replaced quickly so no complaints there.

I would feedback though that the header rings were extremely difficult to push round the tight final bend on the header tubes and scratch up the finish. I used standard split collars and all was well. Maybe the shorter ones produced for this user would be better as standard?

OK, before giving you my figures I must fully confess to being a 'Careful' rider, my wife calls me 'Field Marshall Slow' on the basis that James May would no doubt pass me with ease! I only 'Open her up' occasionally to, er, 'Burn the carbon off the valve seats officer'.

My bike is in totally standard trim in every way except the inevitable MOTAD exhaust and unbelievably I get 48 mpg around town and on a gentle 50 mph cruise up the A1 I got 57 mpg! The gearing is believed to be standard F1 as I bought new sprockets with the chain in a set for the F1 and the revs seem similar to what I remember back in the day ( around 4600 rpm at 70mph )

I think 48 mpg for a more normal individual would be a very good average

Know what you mean Pete, when I first rode my F1 it has a very specific smell when hot ( not entirely down to the rider!  ) no idea what it is, hot laquer or something? its not strong but it instantly took me back to the long hot summer of '76 thrashing around Cornwall on an F1 on me hols!

That reminds me, I must run this F1 down there and get a pic of it outside Driftys in St Agnes just to complete the circle so to speak!

+1 on using heat and washing up liquid.

Another tip is to use a ratchet strap ( or I used a rope 'tornique' ) around motor and carbs to apply constant pressure while you 'jiggle and shove them around as its hard to keep pressure on while doing this.

If they are on ok but leaking are you using the proper clamps?