Technical 650cc Engine with electronic ignition

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Technical 650cc Engine with electronic ignition

Hi Sean yes it does have that additional flap on the air filter housing. It is manually operated so that bendy wire bit is rotated opening and closing the flap and in then sits in the groove in the mounting when it's open.

I am guessing that it is opened on really hot days or after the engine has been running for a long while to send a blast of cooler air up directly onto the carburettor to prevent fuel evaporation and assist in hot starting. So in that respect it is quite a clever little addition.

I can't remember what size that nut is on the end of the crank but I do have one, I think it was 28mm?? So if you are stuck and passing this way you are welcome to borrow it? I know you are up my way evey now and again.
 
9°C tomorrow I am hoping to crack on with the rebuild tomorrow in the relative warmth compared to the last couple of months.

I have all the tinwork rubbed down and degreased so I should have some nice newly painted tinwork to post pictures of tomorrow.

I can't wait all the greasy grim parts have been cleaned so it's all downhill from here with reassembly of the engine and gearbox, then a bench test.
 
Painted the tin work today it came up really well, going to stick another couple of coats on it. I will stick it in the oven to cure it off as it can handle high temperature. Then I can crack on and finish the rebuild and go for another bench test.

I have to rebuild the carb, I purchased a rebuild kit, that has absolutely everything in it but it was quite pricey.

I had to search for a few threads to find the correct gearbox oil for a synchro gearbox and it seems that GL4 is the way to go so that's what I bought.

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Hey bit of a stupid question really Sean. :idea:

My favourite Plastikote enamel.:D
 
Tony,
I am looking at ordering a load of parts from Axel Gerstl.
they do a maintenance kit for the 500 R/126 or the 126/650 square head.


Any idea what the difference is?
 
Sean it's not the square head one, I think some early 650 126's had square cylinder heads similar to the Panda head.

What I always do with Axel Gerstl is put everything in my basket and then copy and paste it into an email to Fred. Shipping is normally €11.90. Is your carb on your 650 engine made by FCO it has a little logo on it like a ship with 3 masts, if so and you plan on rebuilding it you need kit C01055, or C01055/2 or /3. I went for /2 as it said it was German built and I thought it would be more efficient.:rolleyes:
 
Engine is polish 126p 1989.
Carb is a mb28 s1a.
I think you maybe right about the head. Makes sense to order the maintenance kit as it's cheaper than all the parts added together.
Hopefully he will give me some discount as I will be ordering all my engine & suspension parts.
Found out pistons are std as they have 77,0 stamped on the top.
Can't find any markings on the bearings so I am going to presume they are also standard size.
Bores look really good, main bearings look ok. But I noticed the big ends show slightly more wear on the top of the bearing(piston side). I am going to replace them all to be on the safe side.
 
Yes same carb as mine. I asked Fred about the carb rebuild kit and he asked his mechanic who recommended those 3 kits. I believe FCO built them under license from Weber.

I only replaced the big ends as they showed similar wear to yours.

Don't forget to check your starter and alternator bushes in case they need replacing also check the thermostat in a pan of water to check that is operating ok.
 
Tinwork has cured well now so I have started to put it all back together. So for the next few days I will be able to bolt everything back onto the engine. I hope the dog didn't mind me using its bed!!!!!:idea:

In the second picture there is a little odd spacer that starts off at about 12mm and then tappers off to about 8mm and it fits to the end of the thermostat rod on the flap on the housing. I am not sure if I have refitted correctly?

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I am due to replaced thermostat, and I think that washer was on the inside of the flap , cone facing down.
 
Yes your right Darryl it does go on the inside of the flap, I found one of Chris old pictures to confirm that is the case.

It's worth testing your new thermostat before you fit it, put it in a pan of cold water and bring it to the boil, just before it boils you will see it start to move and then there should be a click once it has fully opened.
 
I have got a question regarding the clutch thrust bearing. I have a new one identical to the old one but when I fit the new one and join the gearbox and engine back together the bearing moves all the way to the end of the shaft on the actuating arm and jams.

You can also simulate this with the gearbox free from the engine by moving the arm and bearing right up against the gearbox side of the shaft and again it will jam. It appears to be because the hole in the bearing is slightly larger than the shaft and it allows the bearing to go slightly off centre and not move. If I use the old bearing it is fine and doesn't jam.

I think the difference is that the old one is lubricated on the inside and the new one is bone dry. I feel a bit stupid for asking this but is it ok to grease the inside of the new one? I am just concerned about it getting on the plate. I wouldn't have thought a little bit can do any harm?

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Sounds similar to the problem we had before Tony. If graphite is needed, you can get it in a toothpaste type tube quite cheap..it's used for blackening wood-burning stoves.

Don't forget though, it will never be that far back against the gearbox in practise and isn't meant to be. The actual movement s only a relatively small amount at the flywheel end.
 
Sounds similar to the problem we had before Tony. If graphite is needed, you can get it in a toothpaste type tube quite cheap..it's used for blackening wood-burning stoves.

Don't forget though, it will never be that far back against the gearbox in practise and isn't meant to be. The actual movement s only a relatively small amount at the flywheel end.

Yeah I hear what you are saying Peter but as soon as I bolt the engine and gearbox together it seems to push it right against the back of the gearbox and jams. I suspect a small amount of grease or graphite will probably help or alternatively use the original bearing.

It's probably due the fact that I had to use so much degreaser to clean the gearbox that I have dried everything out. It's the back of the bearing where it folds in to encircle the shaft that is catching. I wouldn't have thought a little grease on that bit can do any harm.
 
Have you tried copperslip? I think that is what it was called. It's a tube of copper based grease and you smear it very sparingly and it's sticks like sh@t to a blanket. It doesn't move about and therefore won't get on your clutch plate.
 
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