RD400D commisioning

[kevb]

Hello All

I recently bought a nut and bolt restored RD400d model. Te bike has had a total engine and body rebuild. The owner had lost interest or the will to live, and it had been left with a number of jobs to complete. I did the jobs to finish it off. Got it running in the garage and it sounded good, revved ok. I also stripped carbs to check for muck and clear jets, all seems fine. Problem now is when trying it down street it would not pull cleanly, just bogged down. Starts first kick, runs ok at tickover speed but not under load. I am going to check the timing first. (Points still used) then move to carb set up and jet sizes etc. Has any one any tips on what to check on this engine, its a long time since I had a points set up bike.

Any tips welcome.

Kev 

[paulsx]

As you mentioned I would check the timing etc and make sure its as it should be. Then when you run it and it bogs down try pulling on the choke and see what happens. If it picks up its running lean if it bogs worse its running weak. There is a lot of talk on the air cooled forum about carb internals etc and air filters, the cheap ones dont have a baffle inside and dont work properly.

[kevb]

Checked timing, set both sets of points to mark on flywheel. I know this is only a rough guide but wanted to avoid taking tank off yet. Removed baffles to try that they were not causing blockage. Bike will rev to 5k then dies. I suspect it is a carb issue. So that is next job. The guy I bought it from did none of the work himself his info was sketchy, he said the carbs had been ultrasonically cleaned and a new keyster kit in each carb. But seem to me the problem is somewhere around that area. If any one has any tips they are welcome.
Kev

[paulsx]

The keyster kits dont have a great rep partiulary the needles. You maybe worth hunting down some genuine parts

[oldelsieboy]

Jul 6, 2016 12:49:57 GMT 1 paulsx said:

The keyster kits dont have a great rep partiulary the needles. You maybe worth hunting down some genuine parts

Ditto, Keyster needles are suspect.
400D parts fiche states needles are 5L1 which are available from Allens Performance.

OEB

[muttsnuts]

yes, carbs need to be right, the air correction circuit is a particular problem on the 1A3 carbs (C/D model),. I have some 5L1 needles if required

Also, your timing needs to be set at 2.4mm, or 2.2mm BTDC if yu want it to be slightly safer, also points gap needs to be right

if the problem is at 5K(ish) then I'd I'd be inclined to say its the air correction circuit, but first off, make sure it doesn't have a 250 airbox fitted as that will give the exact same issue and its amazing how many do have a 250 airbox fitted.

The 400 airbox has a rectangular hole between the top and bottom halves, if it doesn't and there as a series of tubes that is in the centre (air filter fits around the centre), then its a 250 airbox, if that is the case then you need to get rid of those tubes first

HTH

[kevb]

Thanks guys
I got a little further today. Took carb tops off to check needle position. left one was as low down as it would go clip in top groove 5, right carb in groove 3. no idea why? set left to same groove as right. Put it back optimistically, but seemed no different still bogged at 5kish. Does any one know correct needle height setting? I will start again tomorrow and look at the things suggested. I would expect it to have correct air box as it is a UK matching numbers bike, but then again who knows without checking.
Kev

[rsvr1000]

Double check baffles they may be blanked off If pattern ones. If so the gases have no where to escape making engine run lean, trust me on this one , Yambits again

[kevb]

Will do but took them out, and bike still same. Put them back now.