Try these Steve.

https://www.guagerepairs.com/

Cheers Ian

I have heard on good authority that Honda are going to produce "the bike they always should have done" ie an enlarged version of their best selling GB 350S. I'm told it's going to be a 500 but it won't be a new engine, just a re hash of the present engine. I just hope they test/strengthen the bottom end if necessary. (Deja vu?). Time will tell.
Cheers Ian 🤞

thanks Bill, sorry for my tardiness in replying. i took your details and the ones from my manual to the rebore bods
the comment was 'they'll do'
i think they are a bit more exacting than the sort of work required on an SRX
anyway, job done, very nicely too. they also honed another barrel i have which will eventually go onto 'tiggy' the supermono racer i bought from Andy Duncan.
£90 the lot.. well pleased.
reassembled the 400 after giving the head a good going over, lapped in the valves, new stem seals etc.
started 3rd kick!... so had a few poodles round at 40, then 50 mph, about a 100 miles, then had a trot round the coast, kings lynn, hunstanton, cromer yarmouth & back home.. another 150 on the clock, lots of lovely compression good positive sound from the supertrapp, and the tickover is amazing, never had an SRX with such a low, steady & reliable tickover.
now, we get to a longer ride and a bit more speed when i notice on the overrun into a roundabout from about 60 to 40 when i open up on the exit a lot of smoke, i mean a LOT, it clears after a few seconds .... but bloody hell!
if i assume i haven't broken a ring, and i have the ring gaps at 120deg, then the problem must be in the head? i do have a spare head which needs some exhaust studs (just received from Wemoto) and fettling (this weekend if swmbo is agreeable). the only issue is, i'm having to reuse the head gasket as 400 gaskets are like the proverbial rocking horse sh1t!
i'm keen to get the old girl fully serviceable as i want to flog it to fund my final 600 build.
have i missed anything maistro ?
pip pip

I've just had a tank breather problem on my latest project which resulted in similar problems.
In all the many years I've been riding I can't recall this happening before so it's definitely worth checking.
On my bike , a 1989 Honda 400/4, not the classic twin shock SOHC model, there are 2 breather in the tank under the filler which I cleared by running through some electrical wire from top to bottom and another in the cap itself.

Rebuilt another carb just in case although I don't hold out much hope.  I will try and find time to fit it tomorrow and see what happens.
I'll let you know how I get on.
Thanks again.
Richard