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Post by Bakker RD on Nov 1, 2018 22:11:19 GMT 1
![]() Hello, I'm a newbe on this forum and have signed up because I might have an interesting bike to show to the two stroke community. The other thing is that this special bike refuses to fire up and I hope the collective knowledge on this forum can push me in the right direction. This is the story: 10 years ago I was able to buy a rough but very two stroke special. An RD350 31k with an alloy chassis made by dutch chassis genius Nico Bakker. Famous for its racing chassis made for several 500cc riders in the 70's and early 80's. In 1983 Nico Bakker received an order from a Japonese Yamaha dealer to make 50 alloy versions of the stock steel frame. Not all 50 were build and a few stayed in Europe. The chassis of my bike stayed in Holland and was registered in 1985 as a road bike but was fitted with a lot of special parts like mag PVM wheels, alloy fuel tank, WiWo magnesium 4 pot brakes with cast iron vented disk, magnesium tripple clamps cast by PVM for Bakker. Spondon type mechanical anti dive, magnesium Marzocchi 38mm racing forks, a White Power rear shock, Motometer temp gauge and a scitzu tacho. It was running when I bought it but poorly and with a cracked exhaust. I decided to fix the engine first but discovered nothing wrong there. Beautifully reworked cilinders and pistons which were almost new. The last owner had made a c**k-up by fitting a stock base gasket which covered up 50% of the enlarged transfer ports messing up the flow so I reworked that but otherwise it was fine. Only thing I changed was the squish which I set to exactly 1mm by skimming the head. Afterwords I repaired the exhaust and started to work on detailing the bike. last owner had fitted a bicycle computer as a speedo and toggle swiches on the handlebars which had to come off. I found period correct switchgear with all switches in one unit so on the right side I only needed a kill switch. I found a small mechanical speedo reading to 220kph and noticed I lost interest in the wiring part so switched to the cycle parts which I had soda blasted and resprayed. Djuz fasteners and a batch of low head allen bolts were bought and I'm not sure what happened then but in the middle of this work it was parked under a tarpaulin only to be removed a month ago. With fresh inspiration I finished all the wiring and fitted a zeeltronic PCDI 10VT programmable ignition. Iridium plugs, Vforce 4 reeds, Dynatek mini 3ohm coil and had the flywheel lightened and rebalanced. The Mikuni VM34 carburators were cleaned, float height set (were both way off (15 instead of the correct 22mm) and I made a note of the current jetting (55 pilot and 310 main, 6F9 needle with the clip in the middle groove. Air screw 1.5 turns out). But it won't start... There is a spark and there is fuel. It has enough compression but not one puff to prove I'm close. I have set the static angle on the zeel to 34deg and have programmed a flat 20deg curve to check the compensation but nothing happens. Can anyone give some advice? many thanks, William  thumbnail_IMG_6040 by William Van der sman, on Flickr  5D27ADA8-DC82-4693-B204-0B771A7377B7 by William Van der sman, on Flickr  46042299-6BE3-478B-9D95-C8C317D084E5 by William Van der sman, on Flickr |
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Post by Tobyjugs on Nov 2, 2018 0:49:43 GMT 1
Hi William welcome to the forum.
There are a few Dutch members on here, which part of Holland are you living in? I am also a fan of the Nico Bakker bikes.
I don't know much about the zeel. Are you getting wet spark plugs when kicking it over for a bit?
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Post by Bakker RD on Nov 2, 2018 7:18:14 GMT 1
hard to say. I have fitted new plugs. When I peek inside the carbs I see a vapour mist hanging near the reeds. When I kick it over with plugs removed I do not really see mist exiting the head but I'm doubting if I should.
Maybe I need to fit used plugs to see when they wet.
Thanks,
W
PS Holland west.
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Post by Tobyjugs on Nov 2, 2018 7:42:21 GMT 1
If its receiving fuel you should be able to smell it on the plugs.
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Post by mikee on Nov 2, 2018 8:24:43 GMT 1
heat the plugs up then refit and spray some fuel down the carb inlets , give it a kick and it should fire , if it dosent then further investigation will be required , damp/diesel start (ether)might help too
id give the carbs an ultrasonic bath too
mike
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Post by dusty350 on Nov 2, 2018 21:25:20 GMT 1
Hi William Welcome to the forum  Nice looking bike - and quite unique as you say. Try posting this thread in the main section at the top of the forum - more members will see it there Are you trying to start with the kickstart ? Worth trying a bump start with a mate giving you a push ? I once had an aircooled that wouldn't start on the kicker after a rebuild. Started with a push, and then always started on the kicker after that !- who knows why !! Dusty  |
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Post by madmick on Nov 3, 2018 12:53:57 GMT 1
Hi William Welcome to the forum Nice looking bike - and quite unique as you say. Try posting this thread in the main section at the top of the forum - more members will see it there Are you trying to start with the kickstart ? Worth trying a bump start with a mate giving you a push ? I once had an aircooled that wouldn't start on the kicker after a rebuild. Started with a push, and then always started on the kicker after that !- who knows why !! Dusty Makes perfect sense. That’s what I would do. M.M. |
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Post by Bakker RD on Nov 3, 2018 16:46:52 GMT 1
To all of you: Thanks a lot! Today a friend gave me a big push and after about 30 meters it fired and ran! I'm very happy and excited to hear the sound of this bike, which is gorgeous!
There is one problem though and that is that there is a coolant leak. When I fill up the system it almost immediately appears from the base gasket exactly between the cilinders. If I remember correctly there is no water passage between the cilinder and the crank case so were does this water come from? Any Tips?
William
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Post by midlifecrisisrd on Nov 3, 2018 16:53:29 GMT 1
It's most likely from the head gasket between the cylinders and running down the inside of the barrels
Steve
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Post by Bakker RD on Nov 3, 2018 17:42:11 GMT 1
Hi Steve,
I hope you are right and it is only that. Saves me a full top end strip but I cannot understand why the head would leak. Skimmed head, OEM gasket.
Cheers,
William
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Post by midlifecrisisrd on Nov 3, 2018 19:04:27 GMT 1
Hi Steve, I hope you are right and it is only that. Saves me a full top end strip but I cannot understand why the head would leak. Skimmed head, OEM gasket. Cheers, William The secret to building a ypvs top end is only tighten the barrel base nuts finger tight, torque the head, then torque the base nuts Takes up any slight differences between barrel heights and crankcase surfaces Also the base gaskets can overlap and cause probs Steve |
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Post by Bakker RD on Nov 4, 2018 8:34:51 GMT 1
Hi steve,
Is it possible to torque the base nuts (with a torque wrench) after the head is on?
Cheers,
William
PS I read several different stories about the tightening procedure of the head. What is the general view nowadays and is it Ok to use an Altena gasket?
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Post by Tobyjugs on Nov 4, 2018 10:08:45 GMT 1
Before you loosen the cylinder head check the little cooling water pipe flange that bolts onto the cylinder head is not leaking.
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Post by Bakker RD on Nov 4, 2018 12:38:25 GMT 1
Just removed the head and Tobyjugs was right. the gasket between the pipe and the head must have slipped away when I fitted the head ten years ago. So new a headgasket and new flange gasket and I'm good to go;-) How can I tell the make of my old head gasket? It is three layer affair and I measure a total thickness of just 0,6mm. I had the head skimmed to get a squish of exactly 1mm (confirmed with the soldering wire trick) and I see now that there is no edge left between the combustion chamber and the head face. Is this acceptable? I have a stock head to redo it if this is not advisable  kop by William Van der sman, on Flickr Cheers, William |
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Post by marrcel on Nov 4, 2018 14:36:07 GMT 1
Welkom William
I am from 023
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Post by Tobyjugs on Nov 4, 2018 14:53:21 GMT 1
Hi William if you put the same thickness gasket back or even a bit thicker you will be ok. I think a genuine Yamaha leaf gasket was 0.7 mm so it sounds goods. There are a lot of cylinder heads being used without that edge (rand) with no problems. Squish height is important, but more important is the volume in the combustion chamber measured with the piston at top dead center.
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Post by 1966baz on Nov 4, 2018 16:10:32 GMT 1
Welcome in William, what a great looking 2 stroke. Hope you get there soon with the starting issue. As said carbs are often the culprit. I've just rebuilt a pair of power jet carbs and what a difference now!
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Post by Bakker RD on Nov 5, 2018 17:40:59 GMT 1
Hi 1966baz, Lucky for me the Rd started after input from this forum. It was a matter of pushing instead of kicking. The coolant leakage was also pin pointed by this forum. It was the gasket were the downpipe to the downstream hose of the water pump is connected to the head.
All I have to do now is fit a new head gasket, carefully replace the shifted water pipe gasket and take the Bakker to a rolling road for fine tuning of the Zeel advance curve and the Mikuni jetting.
Are there Dutch forum members who can recommend a two stroke specialist with a rolling road preferably in the west?
Cheers,
William
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Post by Tobyjugs on Nov 5, 2018 18:15:20 GMT 1
I can only recommend PS tuning. That is in Geldermalsen, he has a good understanding of the zeel and has plenty of Mikuni jets. Prices for dyno time is not expensive if you change your jets yourself. Its the only person i have used and can comment on. you also have RH Motoren and Knaalportz, you will have too google them for more info.
Please inform us how your experience is with the dyno setup
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chrisk
Drag-strip hero
Posts: 281 
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Post by chrisk on Nov 7, 2018 22:48:27 GMT 1
That is the best ypvs I've seen.
Enjoy it, And if you should ever decide to sell, I would be very interested.
Have fun
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