revtothelimit - motorbike forum

Anyone here really knows how they work friend R is Has been restoring one it has compression and seems that the second carb has been deleted It wont fire under any circs We guess that the thing fires in two different places hence the second carb? but that someone before took it off ( Figuring it want nessesary) anywell founded knowledge gratefully stolen....random RE5 pic of it been worked on

the new indecators were a fortune 200 ish

since this above pic was taken the whole back end has been done hub wheel spokes the lot

No I don’t know, but isn’t it twin rotor?

Two carbs not surprising then.

I think I’ll learn more from you than you from me!

Will a GT500 engine and box fit in it?

Or Triumph 650/750 lump?!

In my late teens, Cusworths Motorcycles in Doncaster had one upstairs in the showroom, it was there for years. I didn't really know about wankels back then, I was more intrigued by the instrument cluster.

EDIT:

I'm getting old an repeating myself.

viewtopic.php?p=93374#p93374

But what CC is it.

I always thought that the RE5 only had one carb.

As far as I can make out the lack of secondary carb shouldn't stop the bike firing up. They come into play at higher revs. Dunno what they had to do to get the same performance without it.

Just looked it up. It was fitted with a two-stage, two-barrel 18–32 mm Mikuni.

Didge wrote: Tue Oct 21, 2025 9:47 pm I always thought that the RE5 only had one carb.

It's hard to work out - they refer to both primary and secondary 'throats' of a two-stage carburettor, which actually sounds like you can't delete it.

Never had a close look at one so, errm, dunno!

Interesting project but I'm glad it's not me doing it!

PS There's an RE5 Owners Club on Facebook. I imagine it's not a huge group.

Thanks for the replieswe are no wiser but have something to look further into we weren't sure if it had a second combustian chamber but the two throated carb sounds right to me two sets of wires to the throttle presumeably off set

My funny RE5 story:
One shows up at the RockStore one morning, lots of people checking it out. Guy leaves after an hour or so.

Five minutes after he left, another one turned up.

2nd RE5 owner: "When was the last time you saw one of these?"

Everyone: "5 minutes ago..."

There was a bit of an article in Classic Motorcycle Mechanics recently (July 2025 edition). One thing that could be relevant is this comment from an RE5 owner -

"I rang a place near Whitby and in explaining what was needed, including a small choke flap, I was told that without it I'd never get it running." Apparently, this part could not be found and one had to be made up. Unfortunately, there are no more details about this choke flap - but it might be worth investigating.

As an owner of several rotary cars, wet plugs/flooded motor are a no-no!
You should not fire it up and not let it warm up properly, they'll gas up and require dry plugs....again.
They make an nsr500 look like a sensible choice as a pizza delivery bike!