Author Topic: RD350 Radjoot cylinders.  (Read 2773 times)

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Online tractorman

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RD350 Radjoot cylinders.
« on: August 18, 2022, 03:27:29 PM »
Has anyone had any success with the Indian 350 barrels on an RD250b engine. Are they more hassel than they are worth to set up to get the bike to run sweetly. I presume the 350b settings won't work with the barrels as they are lower power with different settings.

Offline c50

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Re: RD350 Radjoot cylinders.
« Reply #1 on: August 18, 2022, 04:41:06 PM »
You don’t need to get the indian spec. There’s a guy in the state’s  sells a full power version at a reasonable cost. He supplies TKRJ 4L0 LC pistons with them, I told him I didn’t want them so he discounted the cost instead. Just never got around to ordering them! I have  a set  of the Chinese ones, that’s where they are made, not India. Never tried them as I would want them re porting. They were about £100 set delivered.

There was also a German supplier selling the full power version, we’re expensive and he insisted in including  31K ypvs pistons, so no chance on that one for me.

Online tractorman

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Re: RD350 Radjoot cylinders.
« Reply #2 on: August 18, 2022, 06:23:48 PM »
I know someone who has just bought a import 250B with (they were told) Indian 350 barrels. (could these be chinese ones then) They say it seems very jerky. They don't know if it has had the full 350 conversion. They also have the 250 barrels and pistons and I wondered whether it would be better to go back to the 250 rather than try to get the 350 running right if the barrels are naff anyway. I am pretty short on info, but just wondered if it is possible to get these barrels to work as the 350 should. (I don't know what pistons are being used)

Offline mervin

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Re: RD350 Radjoot cylinders.
« Reply #3 on: August 18, 2022, 08:09:14 PM »
I know someone who has just bought a import 250B with (they were told) Indian 350 barrels. (could these be chinese ones then) They say it seems very jerky. They don't know if it has had the full 350 conversion. They also have the 250 barrels and pistons and I wondered whether it would be better to go back to the 250 rather than try to get the 350 running right if the barrels are naff anyway. I am pretty short on info, but just wondered if it is possible to get these barrels to work as the 350 should. (I don't know what pistons are being used)
probably a good idea the indian spec was not up to much more designed for longevity and better fuel consumption i reckon ,
a european 250 is probably just as good
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Offline c50

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Re: RD350 Radjoot cylinders.
« Reply #4 on: August 18, 2022, 08:44:28 PM »
I know someone who has just bought a import 250B with (they were told) Indian 350 barrels. (could these be chinese ones then) They say it seems very jerky. They don't know if it has had the full 350 conversion. They also have the 250 barrels and pistons and I wondered whether it would be better to go back to the 250 rather than try to get the 350 running right if the barrels are naff anyway. I am pretty short on info, but just wondered if it is possible to get these barrels to work as the 350 should. (I don't know what pistons are being used)

Probably more hassle than it’s worth. Ideally you need the specific exhausts, carb set up and airbox to make it straightforward. Only to end up with the power of a 250, agree with Mervin unless you get the full power version of them.

Offline betty foRD

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Re: RD350 Radjoot cylinders.
« Reply #5 on: August 18, 2022, 09:32:17 PM »
Original Rajdoot barrels were made in India, but the current aftermarket ‘India’ barrels are indeed made in China.
There have been several iterations and the latest one has over cast liners and fin support dowls that the earlier ones didn’t. There's quite a bit written on here about early ones and Dan put them on his track bike.
It is very much horses for courses but at the right price the latest barrels are a very reasonable proposition. The short duration porting when set up correctly is actually a nice ‘high torque’ motor. Peak power still higher than a Uk 250 but oodles of mid range as you would expect.

Suspect no matter what barrel is fitted to the imported 250, the jerkyness is just typical lurching from poorly set up carbs.

Needs less to say, the early ones are now being dumped into the market to get rid.

Rev 'em till they rattle

Online tractorman

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Re: RD350 Radjoot cylinders.
« Reply #6 on: August 18, 2022, 09:52:37 PM »
They posted a photo of there US 250b and I said it was lovely. They then said it had 350 barrels so I said even better, lovely bikes lift the front wheel easy. They then seemed underwhelmed and said it was jerky so I said could be carbs. Then they mentioned Indian barrels and I thought uh oh, heard they are a bit duff. I guess the issues would be carbs and exhausts made for USA 250 with later design Indian barrels being mismatched and trying to jet and adjust to suit. I have 350 barrels on a 250B and the bike is amazing. The 250B is pretty nippy and most people won't ride flat out now anyway so I wonder if the 250 spec would be the way to go. Plus, they don't know if it is a full 350 conversion!

Offline betty foRD

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Re: RD350 Radjoot cylinders.
« Reply #7 on: August 18, 2022, 10:04:08 PM »
I expect with a bit of a fettle it could be a lot better than it is. Sadly many owners sell their bikes either because they aren’t right, don’t know it and want to move on, or worse, struggle to get them right and can’t, give up and let someelse have the pain.
Might be the whole engine needs a refresh or might be that the carbs are full of a yambits ‘jet kit’…. Who know, but really just best to start at the beginning and work through it. Doesn’t take long when you know what your doing and what to look for but I remember thinking a few months ago we are in a different era of new and often first time RD owners. It’s a steep learning curve if you are starting from zit .
Is the guy in Andover too?
Rev 'em till they rattle

Online tractorman

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Re: RD350 Radjoot cylinders.
« Reply #8 on: August 18, 2022, 10:19:06 PM »
No, near Bristol. As you say, a poorly set up bike can be enough to make a new owner very disappointed. The owner is a lady and has ridden bikes all her life, and is of our era. She has not had an RD before and I think this is a bit of a disappointment. Probably worth her getting someone who really knows RDs to look it over and ride it and make an opinion on the issues. I just thought I would ask about the Indian 350 barrels, because with Jap 350 barrels on my 250B I can't stop grinning!

Offline betty foRD

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Re: RD350 Radjoot cylinders.
« Reply #9 on: August 18, 2022, 10:32:22 PM »
Any RD even with a mongrel set of parts should and can make you grin! Indian barrels are no exception.
I suspect her bike is typical of many on the market. Looked tidy but riddled with issues…probably needs a good going over.
Rev 'em till they rattle

Online tractorman

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Re: RD350 Radjoot cylinders.
« Reply #10 on: August 19, 2022, 07:34:13 AM »
Quite true, just a bigger grin with the 350 over the 250.

Offline c50

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Re: RD350 Radjoot cylinders.
« Reply #11 on: August 19, 2022, 08:56:45 AM »
It’s all down to how much you want to mess about. If messing about is the main interest in RD’s then it’s ideal. But if you want a nice original bike, the 250 option makes more sense. I prefer the (proper) 350 over the 250 but I wouldn’t be disappointed which one I rode, have both. I have an original road test from  76 of the UK 250B vs the 350B, he also liked both but for overall fun gave the 250 the win, mainly down to its more entertaining power band. I say it’s down to your mass! Either of them are seriously compromised if your carrying 15 stone + but especially the 250.  I’ve not heard of anyone in this country who has come on and said they have them fitted to otherwise a UK bike carb/exhaust wise and confirm it works properly. The Rajdoot was designed to have low power and all parts are critical to decent running, carbs, airbox and exhausts.


Offline betty foRD

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Re: RD350 Radjoot cylinders.
« Reply #12 on: August 19, 2022, 09:54:36 AM »
The mess about factor and how much you want to mess about is a very good point. I’ve used the latest barrels to good effect and as I recall it was only the needle clip positions that ultimately seemed to benefit from being different. But I had started with safe extra fuel and worked my way back. Who knows how repeatable that is.
RDs are fairly hands on at the best of times, particularly if you are nursing a number if age related aliments! The bike I mean … so unless you or whoever is doing the work are able to work from first principles, then having a very set of defined factory defaults makes getting to a useable starting point very easy.

Actually this type of discussion is quite difficult to close with simple conclusions once you are in the ‘non standard’ territory. All the variables of why you are intending to do something and expectations for the outcome are so subjective in the non standard world.

On the other hand. If a bike is put back to 100% standard settings then it’s much easier for remote assistance from the forum to identify and sort a snag list.

In this particular case, what I would do personally and what I suggest a novice owner does are probably opposites. I’d attempt to dial it in , letting the engine and bike ‘talk to me’ and along the way diagnose any underling other issues. Recommendation  for a novice owner would be to go back to standard.

« Last Edit: August 19, 2022, 10:04:35 AM by betty foRD »
Rev 'em till they rattle


Offline c50

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Re: RD350 Radjoot cylinders.
« Reply #14 on: August 23, 2022, 01:16:53 PM »
That’s the ones. Why oh why do they have 31k pistons?!?! If it’s the same one he is prepared to sell just the cylinders at a discount.