Messages

Thanks guys, I won't worry about it anymore.

I'm pretty sure it's Moto Carrera, I got some price lists and brochure downloads from 2001 2002 with the bike and although the pictures aren't great, I can recognizing some of the details. Question in my mind is is there any difference in width at the wheel between a 400 and a 350?

I undid the rear axle and was surprised to see the swinging arm spring apart, as you can see in the picture. My guess is, and it is a guess, that it is a RD 400 swinging arm. My frame is definitely a RD 350 and the swinging arm fits properly at the pivot, just seems to be too wide at the aft end. It's actually 10.5 millimeters and it's the same amount at the top mounting for the shock absorbers. It had been used with the axle pulling the swinging arm together and lining it all up, but putting it all under some preload, perhaps that's not good for the welds etc.
I could make up spacers for the axle and I could also space out the shock absorber top mounts?
Would a RD 400 axle fit in the 350 rear hub but be the right length?
Looking on the Internet, they do have different part numbers. People selling them on eBay list them as fitting both.
I bet you guys have been here before, but I haven't and I really appreciate your advice,

Wow! That's a whole world of mopeds! I couldn't find my way to an RD 350 ignition system.
I turned 16 in 1977 in England. You could ride a moped on a permit at that age. They were mopeds everywhere, the cool kids had Yamaha FS1E's. I probably wasn't cool and certainly had no money, I rode the bus.

Thanks for the replies,
I'll check the nature of the existing mounts, whether they're rubber, what condition they're in.
M ln NC, I know you don't approve of a total loss electrical system and I totally understand why. I'm not sure I want to put a 50 year-old alternator back in the bike and purchase something like a Dyna S for $375 (or put the points and condenser back in) and as much as I would like a vape system, it looks like they're $800. I need to get the bike cleaned up, put back together and ride it even with its limitations, first.
That's an interesting looking engine in front of your air cleaner manifold. Did you 3-D print that? Can one print with rubber or something like it?

Good morning,
Dying to get started on this project, but for now I just get to stare at it and think about it.
As you can see in the picture it has larger Mikuni carburetors and Uni pod filters. There's not really enough room for the filters, packed in against the frame tubes and each other, their surface area to the atmosphere reduced. I'm assuming that it worked and would do so again, but it doesn't look very elegant. Are there any alternatives?

You can see the engine mounting plates on the top of the engine are missing. Is there any reason why they wouldn't be there?

The bike has a PVL ignition system, I don't see it discussed much in this forum. Again, I assume it works well enough, but I don't think there's much love for it around here?

Thanks for the replies. At some point in the near future I'm going to disassemble the engine to change the main seals, have a look at the clutch etc. I'll measure the height and width of the ports, measure the amount of squish etc. If I could post the information here then perhaps you guys could take a look at it?

So, I've required this bike that I'm told needs 110 octane fuel and I'd like to establish whether it actually does or not. If I were to measure cylinder pressure with a compression tester would that be enough information for an educated guess?
Reading about the subject, pressure is not the only factor in octane requirement and I imagine experience and careful jetting are key?
I haven't even found a table that shows compression versus octane.
Would a compression test be done with a cold engine or a warm engine?
Should a compression test be done before a rebuild, would assembly lube affect the compression test, I imagine it would.
Thanks

OK, I appreciate that. I would like to take the engine to pieces and give it a thorough examination and I will. The clutch is not releasing, and I could measure the height and width of the ports and get some idea of the tune. It's just the monkey on my back whispering, you have enough to do already, mow the lawn, paint the trim.
Any particular brand of seals, genuine Yamaha, something off Amazon?

That sounds good regarding the middle seal. Can the two outer seals be replaced without splitting the casings? Automan wants to see Teflon tipped seals, what is it of which he speaks?

Point taken about the total loss lighting.
The crankshaft seals, I imagine if the left-hand one goes, you're gonna experience loss of crank case compression, what about the right hand seal? pressurization of the transmission, transmission oil in the crank case? How catastrophic is any of this?
I see there's an oil seal in the middle of the crank. I understand that my crank shaft has been welded though I haven't verified that. If so, I imagine changing that seal might require sending the crank to a shop that does such things?
Thoughts?

Thanks for the replies. I'll look for a set of Bridgestone tires.
To answer some of the points you raised, it has a PVL ignition system and a small lithium battery to run the lighting. I need to find out the capacity of the battery and measure the draw the whole system places on it. I should change all the bulbs to LED to reduce demand.
 I scrounged up a pint of 116 octane and mixed it up a little oily. The bike started third kick, I switched the chokes off, and it idled immediately, perhaps a little fast(no tachometer) Responded well to blips of the throttle. Ran it for only a few seconds. A little later, I couldn't resist restarting it, one kick. I think from that I can assume the seals are working at present.
I want to talk about compression and octane but I think I'll start another thread just to keep it tidy.

A new member here, thanks for having me. I've owned a few bikes over the years, including a BSA Bantam, a couple of MZ 250 supa5's, a Benelli 250 twin and a RD400
I've just acquired this RD 350 which was built as a race bike and used as such, but the original builder was getting it ready for the road. I intend to clean it up and finish off It's return to the road.
It's been sitting for about nine years and has a little surface corrosion and dust, the tires are shot.
The guy who built it it's not very well and so information from him is not available, but a friend of his has filled me in a little.
What I know, it has a welded crank, no alternator(runs on a small lithium battery) larger carburetors, needs 110 octane fuel, barnett clutch springs. I don't know about porting or what the actual compression ratio is.
It has an aluminum swinging arm, Works shock absorbers, some kind of valving in the forks. I think the seat, swinging arm, expansion chambers and resets are Moto Carrera?
I would certainly appreciate some help on certain aspects and so if I may ask, here's my first question.
It has Buchanan sun rims front and rear, they are both 2.15×18. The tires are Avon AM23 130/65 (just clears the chain) and AM22 110/80, plenty of tread left, but the side walls are cracked and ruined from sitting.
Expensive tires if you can find them.
What am I going to replace them with? I've searched the Internet for size suggestions and what is actually available and it's not entirely clear to me. The Bridgestone BT 46 seems available here in the US in almost the right sizes, but it appears to be a radial tire. Should this bike have a bias ply tire? Back in the day I was able to change bias ply tires on smaller bikes with tire irons, would love to be able to do that again.
Thoughts or experience?