I must be blind or daft.....I need the basics

[mossquire]

sorry but I’ve looked on this site and the air cooled and can’t find a thread for basic info on plug gap, points gap, how to set the timing up (I found a timing thread and now can’t find it again. Can anyone shed light on it for me LOL. Took it out for its first run for several years and it ran like a dog. Missing on one cylinder on everything other than cruising with no throttle. I thought I would start with new plugs and recheck the points gap and timing to see what I’ve missed if anything and then onto the carbs. Ahh the joy of having a real bike. I’ve missed travelling at 20mph farting and spluttering (the bike, not me). 

1974 rd350b 

cheers

[ianr4863]

The A/C forum has a "Manuals and Guides " section that you can look at , its in the Hot Topics bit .
You might need to look at the R5 manual for info on a 350b . Otherwise maybe a Haynes manual ?

[reedpete]

From best memory and general, 15thou on the points, 20-25 on the plugs.
Timing is best set with dial guage etc as per manual, but there actually a timing mark on the rotor. Once set with a dial guage I always look to see how a particular crank and rotor time up. They are always very close, so if the bike is running like a dog and you want some basic settings a reference point then you can just use the timing mark. On an unknown bike I would always err to the retarded side if the timing mark, a because it allows a safety fa tire but also because generally they run better with a little less timing than specified. Ie closer to 1.8 BTDC than 2.0mm

Fresh fuel, strong battery, basic spark settings and clear pilot jets and there really shouldn’t be a problem.

[mossquire]

 Thanks mate, I have sent for a Haynes manual and a dial gauge and see if that helps with a new set of plugs and the points cleaned and set. Its been standing for a good 4 years so if that doesn't sort it I will have go with the carb jets as well. I missed last weeks sun so maybe next summer

[mossquire]

well new plugs, cleaned and reset the points, timed with a dial gauge, carbs cleaned in ultrasonic cleaner and no difference...………… any ideas, getting fed up now

[reedpete]

James, if this is the AC you just bought and it hasn’t really run since the restore then it might be an assumption to conclude it was running ok years ago.

I’d start by being clear about was is confirmed fact and what’s not.

There’s two ways to go about proceeding from there.
Either work through methodically checking top end and electrical parts before running the engine again.
Or use run time info such as wet or dry plugs to indicate if this is a fuel or spark issue.

As I understand it , starts easily and idles nicely but won’t run on load...

If you want a few guesses...

Bad connections
Yambits fuel cap seal without the air hole
Those fuel filters causing grief
Fuel tap not flowing symmetrically - some refurb kits result in one side not flowing
Carb internals wrong
Carb Slides in the wrong side
Blocked or wrong baffles
Baffled airfilter in backwards

Your welcome to give me a call on the weekend if you want to chat even if it’s to restore sanity....we’ve all been there at one time or another..

[mossquire]

Cheers Pete, Sorry, I was not here this last weekend and not again this. I am not sure it ran after the resto but I presume so. The guy lost his sight and never rode it but the resto person must have checked? I have now stripped the fuel tap, cleaned it and done a fuel flow test. I get a full stream from the O/S and a trickle from the N/S which, if you block the O/S becomes a stream too. It obviously favours the O/S as its the first exit. The fuel emptied at about a litre a minute from the main and slightly less on reserve. The cap shut/open made about 30% difference to both flows which reduced the flow on the N/S to almost a dribble. I have not stripped the cap although the sealing ring does not look new but the metal is corroded. I have started to take the carbs down again and the main jets are 140 and the pilots are hard to read but either 130 or 30 so probably 30. I will check the needle, slide ect today. The air filter is the baffle type and was in the wrong way up so that doesn't bode well!!

[mossquire]

well after a lot of messing around, checking and rechecking it appears that I have 1A100 carbs on it which are from the 400 and sounds like its jetted for a 400 as well. That cant be good but better that having the airfilter at least upside down and possibly back to front. It has paid to go right back and start with the obvious dumb ass stuff which you assume will be done. Not saying this has or will cure it but its a learning curve and when I have done I will know the bike is right. So as I want the bike as standard as possible I guess I will have to eventually source 350 carbs and see if I can sell the 400s. I want to get the thing running first though and as far as I can see the 400 carbs will be fine if jetted correctly...….Thoughts? 

[muttsnuts]

make sure the battery is a good one and fully charged, if it isn't it will not start no matter what you do, carbs will be fine for starting purposes for sure

[bigal]

I think I need some 400 carbs mine are 1A2 00

How much !!