New (to me) 400c

[Busby]

Off to PJME tomorrow with the crank and barrels. 😀

[Busby]

Just heard from PJME that my crank and barrels are done so I thought I would look at the cards seeing as it might get finished soon.

778DA237-14E5-4E6C


[url=https://flic.kr/p/2npb4kP]A5139AC7-EF55


Decided to strip the paint off


As you can see the left hand carb has a slide that does not even fit in the barrel of the carb. That carb is also missing the oil input feed to body🙁

This is a shame because I almost bought a set of carbs from ebay last week.

I will have to keep a look out for some.

[5port]

OK, The carbs are a bit tricky, lots of scope to spend £££.    However, if you buy carefully, it is not too bad.  You are looking for a set of carbs marked 1A3-00.  The carbs you have are earlier RD250/350/DS7/R5? that are the wrong type. You might find that 1A3-00 carbs are expensive but, you might be lucky.  Come back here if you have problems.  In any circumstances, only buy good carbs without corrosion inside. Also, bank on buying all new jets and needles, although you can be lucky.  Don't plan on using "carb kits" for rebuild, use gen Mikuni.

 5port

[Busby]

Hi 5port,

Many thanks for that. I did wonder why the numbers didn’t match the bike when I looked at them originally. I got sucked in because the bike only has 10,000 miles on the odometer and I thought it wouldn’t be too messed about with. Ah well live and learn

[5port]

Hi 5port,

Many thanks for that. I did wonder why the numbers didn’t match the bike when I looked at them originally. I got sucked in because the bike only has 10,000 miles on the odometer and I thought it wouldn’t be too messed about with. Ah well live and learn

Yes.  What numbers do you have on those carbs?  They can be worth a fair bit to someone else. 
However, the correct carbs for your bike are the 1A3-00.  They are quite different in detail to those earlier carbs you have.  You have probably read that it is possible to modify the later 250 carbs for the different 400's but, it is not all straightforward.  You must also decide if you really want the "correct" 1A3-00 carbs on your bike.  Price is possibly the issue.  See what you can find!

5port

[Busby]

Hi 5port,

Carbs are labelled 361 A3.

Just going to do a quick check to see what they fit

[Busby]

Rd 250 73,74 and 75

[5port]

Rd 250 73,74 and 75

OK.  I can't find an exact Yamaha ref for the 361-A3 but, model 361 is the early RD250 that you list and likely that they are just with a slight change.  The exact jetting would need checking for whatever they are fitted to, as these were on a 400 it is likely they are not jetted standard.  That is the same for almost all old RD carbs.  Condition is the key, if they are clean inside, that is the main thing.
Cheers

5port

[Busby]

Hi everyone, been a little while, the 350 lc has gone lame and I have been taking a look at that. Any way some pics on progress

A7A1B34C-11D

Honestly darling it’s fine 😂

All masked waiting for paint

[url=https://flic.kr/p/2nwjjPY]8C0D459D-9C5

[5port]

Don't put alloy parts in the dishy washer, the salt and chemicals can damage alloy. 

5port

[Busby]

On with the paint

[url=https://flic.kr/p/2nCCsYu

[Busby]

On to the recon crank



The pins for the inner bearings are too long

[Busby]

Soon sorted out with a carbide cutting disk

[url=https://flic.kr/p/2nCzYyd

[5port]

Not the best idea with all the bits of steel and carbide dust getting in yer new crank. Probably better to do the slight mod on the cut-out in the lower case for this, it is just alloy and you can easy clean it spotless before build.

5port

[pidjones]

Not the best idea with all the bits of steel and carbide dust getting in yer new crank. Probably better to do the slight mod on the cut-out in the lower case for this, it is just alloy and you can easy clean it spotless before build.

5port

I agree. Although, careful masking, plastic bags, vacuum, and grease application might protect you from the flying debris.