Author Topic: Project X 350cc conversion  (Read 4979 times)

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Offline Paul Dawkins

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Project X 350cc conversion
« on: October 14, 2012, 04:53:05 PM »
After next weekend and the Stafford show Project X gets laid upfor the winter.

The bike has covered a few thousand miles now and the top end was rattly when we put it on the road.

I was thinking why dont we change the top end and other neccesary parts to a 350CC, this would make a good restoration guide and WellARD article plus the bike would go better.

We have some funds from the DVLA dating money available to spend on the bike.

So we wil lneed RD350 A/B barrels/heads/oil pump and primery drive.

The bike will also need a service.

What do we all think and has anyone got any parts available?

I will also MOT the bike next year at no cost to us.


Southampton

Offline Cargers

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Re: Project X 350cc conversion
« Reply #1 on: October 14, 2012, 05:26:34 PM »
Good idea Paul,
 there are quite a few members asking questions about doing this conversion.
I converted mine about 4 years ago and have since done a lot more tuning/de-tuning mods.I can try and help with any queries you may have.
Ian.
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Ex race RD350 project
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Offline saddler

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Re: Project X 350cc conversion
« Reply #2 on: October 15, 2012, 12:17:44 AM »
sounds like a plan chaps - perhaps a post in the wanted section may get the ball rolling  ???
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Offline Preload

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Re: Project X 350cc conversion
« Reply #3 on: October 15, 2012, 08:51:14 AM »
Selling the old 250 top end in the For Sale Section should supplement the cost as well as you'll need gaskets and sprockets etc..
RD350B (Mitsui Mongrel).
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Offline Paul Dawkins

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Re: Project X 350cc conversion
« Reply #4 on: October 15, 2012, 07:04:56 PM »
Can someone do a list of what we will need.

Why do we need Sprockets?

I thought we would need

Heads
Barrells
Piston kits
Oil pump
Primary drive
Top end Gasket set

Anything else?

Southampton

Offline speedfreak

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Re: Project X 350cc conversion
« Reply #5 on: October 15, 2012, 07:08:22 PM »
longer barrel studs ;D
If you can't fix it with a hammer, you have an electrical problem.

Offline Preload

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Re: Project X 350cc conversion
« Reply #6 on: October 16, 2012, 01:31:39 AM »
Can someone do a list of what we will need.

Why do we need Sprockets?



Doesnt a 350 have taller gearing?
RD350B (Mitsui Mongrel).
Runner up Yamaha Donington Japanese & Modern Classic Bike Show 2013

RD400C (now registered) :-)
FJR1300 Mk1 and best one
Tmax XP500
Nippy Norman
Aprilia Habana
The lastest CBX750F basket case.
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Online mervin

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Re: Project X 350cc conversion
« Reply #7 on: October 16, 2012, 07:13:32 AM »
Nah it is the primary gearing that is different. i was advised to git 400 primary gearing with the 350 barrels
Motorcycling is not, of itself, inherently dangerous. It is, however, extremely unforgiving of inattention, ignorance, incompetence, or stupidity"

Offline Preload

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Re: Project X 350cc conversion
« Reply #8 on: October 16, 2012, 09:59:43 AM »
That would be even more expensive, right lets all keep a look out at the staffs for a whole engine cheap ;D
RD350B (Mitsui Mongrel).
Runner up Yamaha Donington Japanese & Modern Classic Bike Show 2013

RD400C (now registered) :-)
FJR1300 Mk1 and best one
Tmax XP500
Nippy Norman
Aprilia Habana
The lastest CBX750F basket case.
RosPa trained & Warwickshire Mag Member

Offline Cargers

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Re: Project X 350cc conversion
« Reply #9 on: October 16, 2012, 10:17:37 AM »
I have run mine with standard 250 primary and 35o primary gears, With the 350 gearing the rev counter does not read correctly.
I am still running the standard 250 oil pump with no problems (approx 4 years use)
The 350 exhaust studs are different to the 250 so you will need to change or adapt the down pipes/exhaust flanges.
Ian.
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Online mervin

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Re: Project X 350cc conversion
« Reply #10 on: October 16, 2012, 10:33:33 AM »
TBH with the Zemlic CDi and rev limiter it should come to no harm, i was advised it was easy to over rev with 250 gearing and people have seized them like it, and if it does rev out to quickly a couple of teeth smaller on the rear sprocket  would help, as for oil pump with modern oils it should be ok on the 250 one i reckon
Motorcycling is not, of itself, inherently dangerous. It is, however, extremely unforgiving of inattention, ignorance, incompetence, or stupidity"

Offline chrisg.007

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Re: Project X 350cc conversion
« Reply #11 on: October 16, 2012, 05:37:57 PM »
Hi, the 350 intake is at a different angle,so the airbox mounts maybe required to be resited or fit the  350 Y boot and TDR filter mod. The exhaust port is also at a different angle,but the expansion pipes may fit.
good luck
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Online mervin

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Re: Project X 350cc conversion
« Reply #12 on: October 16, 2012, 05:43:51 PM »
I am sure our man that bult the pipes can modify them if neccesary
Motorcycling is not, of itself, inherently dangerous. It is, however, extremely unforgiving of inattention, ignorance, incompetence, or stupidity"

Offline chrisg.007

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Re: Project X 350cc conversion
« Reply #13 on: October 17, 2012, 05:06:35 PM »
Hi, On the subject of oil pump, I agree with merv. The std. cab jet is 120 (I think) and I have up-jetted to 140 for the 350cc convertion (although not tested), only a marginal increase in fuel/air intake.I am goint to add a little in the tank when I finally get it going. Adjusting the oil pump cable would only increase oil flow up until full throttle, so at full bore it will not be getting any more with a pump adjustment than the 250.
chris
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Offline Paul Dawkins

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Re: Project X 350cc conversion
« Reply #14 on: October 21, 2012, 03:34:56 PM »
Thanks to Kev (TZ250H) we have most of the parts required to do the conversion for a very good price.

Barrels, heads, primary drive, oil pump and drive and a few other bits all for £210
We may have to rebore one barrel and we still need piston kits and gaskets but thats all we will need.

I have not unloaded my van yet but will do tomorrow and get some photos. It all needs a good clean and a good looking at.

We need a volanteer to sort the rebore and do the conversion next....

Southampton