Yamaha SZR 660 conversion to 350 YPVS - ( TZ250 replica )

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Ricino
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Location: Madrid - Spain

Yamaha SZR 660 conversion to 350 YPVS - ( TZ250 replica )

#1 Post by Ricino » Thu Mar 14, 2013 6:27 am

Hello folks,

First of all I´d like to thank you all for making this project possible, because here in this forum I´ve learned so many things, thanks to all the generous and passionate people who not only share their knowledge and input, but also fabricate new pieces when they´re not available anywhere else. Otherwise I have to admit that I wouldn´t even dare or maybe I woudn´t have thought about the real possibilities of a project of this kind.

Several months ago I bought two bikes, being the first one a ´88 Yamaha RD 350 YPVS (so is it named here in Spain for this brazilian-made bike)
Then I found a very cheap Yamaha SZR 660 4SU, a TZR 250 derived motorbike with a XT 660 mono engine, also very similar to the later versions of the Yamaha TZR 125 4DL, both built in Belgarda-Italy. Both bikes were neglected as hell, but good enough to start a project; they are registered.

Here is a picture of both cousins before they were disassembled

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I don´t like the original aesthetics of the SZR, so I´ve bought a 4DL tank (bolt on, no modifications required) and a set of Yamaha TZR 250 4DP 1994 racing fibers.

My goal is to build a GP-like registered motorbike (once homologated), lightweight and powerful and with tons of spares available in the long run.
I know the real thing is the real thing :smt040 but for me this is more than enough.

Image

This project is going to take a long time to be accomplished (I have three kids age 10, 9 and 6) but will try to be constant, which is most important for me.
I will list all the goodies in following posts, with references and prices.

Here is the bike disassembled and ready for engine mounts modification. I already have removed the upper rear mounts and will have to remove the front mounts because they are very narrow. I will have new mounts welded. The engine is empty from all the heavy steel internals, except for the chain sprocket´s.

In this picture I have mounted the old 660 engine just to locate the original sprocket´s position. The three axis (engine sprocket-swingarm-rear wheel) trace a straight line when the suspension is mid compressed.
As said before in this forum, the 350 engine will have to be mounted as far back as possible (5 mm. gap betwen engine and swingarm)

Image

And here is the bike once I started to figure out what to do with the mounts.
There are only references of the 4DL conversion in the whole www, and nothing but a lost picture belonging to a french man that has altered SZR frames to accomodate 350 engines ---> http://forum.2temps.fr/download/file.ph ... &mode=view" onclick="window.open(this.href);return false;

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(Edited due to some mistakes)
Last edited by Ricino on Thu Mar 14, 2013 5:50 pm, edited 1 time in total.
Yamaha SZR 660 '96(4SU) ---> in the process to YPVS hybrid!

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JonW
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Re: Yamaha SZR 660 conversion to 350 YPVS - ( TZ250 replica

#2 Post by JonW » Thu Mar 14, 2013 6:29 am

Great build! Cant wait to see and hear what you think.
80 XT500 Supermoto!
81 RD350LC Resto
82 RD421LC Hybrid
82 RD350LC decapitation project
82 RD250LC JDM '251LC' YPVS
83 RZ350 Resto
84 RZ500 Resto
85 RZ350 F1 Resto
86 RZ350 F2 Resto
86 RZ350 F2 Hybrid

Like Watches? www.PloProf.com & www.DeskDivers.com

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Benno #03
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Re: Yamaha SZR 660 conversion to 350 YPVS - ( TZ250 replica

#3 Post by Benno #03 » Thu Mar 14, 2013 12:40 pm

Best of luck Ricino.
76 TZ350(project).
82 RD350LC.
82 SR250.
83 RZ350YPVS.
88 RZ250 YPVS(project).
83 FJ1100.
96 YZF750R(track bike).
99 YZF1000 R1.
00 YZF1000 R1.

72 CB750four.
Lifan 125 Pitbike.

Paul8899
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Re: Yamaha SZR 660 conversion to 350 YPVS - ( TZ250 replica

#4 Post by Paul8899 » Thu Mar 14, 2013 5:20 pm

Looking good so far , I'll be watching this with interest .

I've got a question for you , can the engine go higher in the frame ?

Ricino
Posts: 238
Joined: Thu Mar 10, 2011 8:24 am
Location: Madrid - Spain

Re: Yamaha SZR 660 conversion to 350 YPVS - ( TZ250 replica

#5 Post by Ricino » Thu Mar 14, 2013 5:42 pm

Thanks JonW and Benno for your words, I'll try to do my best and will need lots of luck :-)

Hi Paul,
Do you mean higher as in the third picture (starting from below)?

If I want to keep a correct the-three-axis alignment it can't go really high with the engine. And putting it higher will not clear the original front mountings, as they have a very narrow gap inbetween and touch with the cylinder's sides (power valves). They are also quite asymmetrical and aren't a good base for some bolt-on plates, for example.
Yamaha SZR 660 '96(4SU) ---> in the process to YPVS hybrid!

tzr350
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Re: Yamaha SZR 660 conversion to 350 YPVS - ( TZ250 replica

#6 Post by tzr350 » Fri Mar 15, 2013 4:45 pm

Looking forward to seeing posts on this thread. Looking good so far.

Getting the engine higher in the frame will give you more ground clearance with the exhausts. I think thats why the french guy cuts the front mounts off and welds new ones in.
Would you be interested in selling the rear mudguard and radiator guard if so how much? Also can you post to uk?

Ricino
Posts: 238
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Location: Madrid - Spain

Re: Yamaha SZR 660 conversion to 350 YPVS - ( TZ250 replica

#7 Post by Ricino » Fri Mar 15, 2013 7:38 pm

I want to keep the rear mudguard, but I have found one for you in eBay, just copy and paste this number 200812198687
I'll be willing to sell the radiator cover, so I'll ask in the post office how much is the shipping cost to UK :smt023
Yamaha SZR 660 '96(4SU) ---> in the process to YPVS hybrid!

tzr350
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Re: Yamaha SZR 660 conversion to 350 YPVS - ( TZ250 replica

#8 Post by tzr350 » Fri Mar 15, 2013 7:46 pm

Sorry I meant the ypvs mudguard and rad cover. As for the hugga there 17.30 gbp new and still available.

Ricino
Posts: 238
Joined: Thu Mar 10, 2011 8:24 am
Location: Madrid - Spain

Re: Yamaha SZR 660 conversion to 350 YPVS - ( TZ250 replica

#9 Post by Ricino » Mon Aug 05, 2013 7:43 pm

I have been collecting some goodies and working a little bit.

I finally removed all the original engine mounts, and getting ready to fabricate some new ones.
I started with the rear mount, but I do not own any special tools so I used some old school hand-CNC :smt003 after some sprockets alingment

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Last edited by Ricino on Tue Aug 06, 2013 8:11 am, edited 1 time in total.
Yamaha SZR 660 '96(4SU) ---> in the process to YPVS hybrid!

Ricino
Posts: 238
Joined: Thu Mar 10, 2011 8:24 am
Location: Madrid - Spain

Rear mount

#10 Post by Ricino » Mon Aug 05, 2013 8:41 pm

Here´s the rear mount. I opted to bolt it to the frame, instead of welding it because the mount´s screw is too long and wouldn´t fit between the frame´s side and the mount itself.

The next step is to fabricate the front ones and then figure out how to include the steady bars; I believe they´re indispensable to contain the engine´s vibrations because the OEM elastic mounts are in fact very soft and the whole engine would be too shaky without them. I also will include the OEM rubber washers which are also very important to contain the engine´s torsions during strong loads.

Image

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PS. Sorry for all the filthy shitte around :smt003 , but blinging will come once the important things get accomplished.
Yamaha SZR 660 '96(4SU) ---> in the process to YPVS hybrid!

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JonW
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Re: Yamaha SZR 660 conversion to 350 YPVS - ( TZ250 replica

#11 Post by JonW » Mon Aug 05, 2013 9:11 pm

nice work, especially cool to know you did this by hand.
80 XT500 Supermoto!
81 RD350LC Resto
82 RD421LC Hybrid
82 RD350LC decapitation project
82 RD250LC JDM '251LC' YPVS
83 RZ350 Resto
84 RZ500 Resto
85 RZ350 F1 Resto
86 RZ350 F2 Resto
86 RZ350 F2 Hybrid

Like Watches? www.PloProf.com & www.DeskDivers.com

Ricino
Posts: 238
Joined: Thu Mar 10, 2011 8:24 am
Location: Madrid - Spain

Re: Yamaha SZR 660 conversion to 350 YPVS - ( TZ250 replica

#12 Post by Ricino » Tue Aug 06, 2013 8:03 am

Thanks, John. One certainly feels a special pleasure and connection with the materials when things are entirely done by hand, it makes me really happy.

I mentioned filthyness in the last sentence of my last post. And I have discovered the benefits of soda blasting! A mid-size air compressor and a gun like this Image is all needed to obtain very nice results.

Baking soda is very cheap when bought in bulk quantities and leaves metal surfaces like new, factory finish appearance. The only downside is that soft plated (like zinc), polished or other shiny surfaces that are not really hard could loose its blinginess. Neither should it be used on plastic surfaces, they get easily pitted.
I also like that all you need is a good shower afterwards (Glass beads are also very nice and effective to leave a smooth finish on metal surbaces, but it is a PITA to work with unless you wear an astronaut suit). Anyway... gloves, safety goggles and breathing protection are mandatory.

Here are some before and after pictures :

Image

Image
Yamaha SZR 660 '96(4SU) ---> in the process to YPVS hybrid!

Ricino
Posts: 238
Joined: Thu Mar 10, 2011 8:24 am
Location: Madrid - Spain

soda blasting

#13 Post by Ricino » Tue Aug 06, 2013 8:05 am

some more pics...

Image

Image

Image
Yamaha SZR 660 '96(4SU) ---> in the process to YPVS hybrid!

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Bngt
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Re: Yamaha SZR 660 conversion to 350 YPVS - ( TZ250 replica

#14 Post by Bngt » Tue Aug 06, 2013 12:26 pm

The black layer of low friction polymer on the throttles is needed to keep them from sticking.
F2 1986 project (ZX636R suspension)
F2 1987 The mule, test bench for tuning.
31K 1984 Donor
TZR 2MA 1986 Racer
TZR 2MA 1987 Stock
ZX10 1988 Cruiser
VTR 2005 (with CBRRR suspension, brakes and wheels)
Husaberg FS 570
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Re: Yamaha SZR 660 conversion to 350 YPVS - ( TZ250 replica

#15 Post by Hellgate » Tue Aug 06, 2013 12:57 pm

What a cool project.

What brand is you soda blaster?

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Pete

'12 Tuono V4R APRC, '05 R6, '88 RZ350, '82 XV920R

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