Hmm, now I'm really confused. Just had a look at the 4DL and DTR manuals, apperently the bore on the dt is 56.4, I always thought it was 56mm.
So from what I've read, the bore x stroke is 56 x 50.7 on the tzr 4dl and 56.4 x 50 on the dt. The 4DL also runs a much higher compression ratio, of 12.8:1 over the dt's 6.8:1. So now I'm not sure what to do assuming that's correct as the piston wouldn't reach TDC with the dt bottom end
-- Edited by Petrol_head on Wednesday 11th of July 2012 04:52:07 PM
Right, found a 4dl cylinder with a 3mb head (mine's the 3bn with the weird squish). So that should bolt straight on right? Also anyone konw what piston would I need, all I could find on PJME was a flat top for a 4FU but does the 4DL run a domed piston normally, especially with the 3MB head?
I'm sure the TZR piston in mine has a domed head, now whether the flat top one is for the 4FU nicosil barrel, and the domed piston for the 3MB, steel lined barrel, I'm not sure.
Are they both 56mm bores as standard then? So you could just use the DT piston, or would it use a different sort of piston as it's a nicosil lined bore?
Saying that, just remembered he had a piston with it, and that was domed but it needed replacing.
Not even 100% sure they have the stroke, pretty sure they do though.
Hmm, well PJME, me and the rest of the internet measure the bore to be 56mm on the dt, so think my manual's wrong. Think it should just bolt straight on which is nice.
So the later dt's have a 56.4mm bore and the earlier dt's have a 56.0mm bore then? I thought they were all the same tbh.
What I'll have to do is when I get this cylinder I'll take my old piston that came out before I re-bored it and see if it's the same size as the one that he's got with it. Hopefully it'll be the same size a fair bit more powerful!
So the later dt's have a 56.4mm bore and the earlier dt's have a 56.0mm bore then? I thought they were all the same tbh.
What I'll have to do is when I get this cylinder I'll take my old piston that came out before I re-bored it and see if it's the same size as the one that he's got with it. Hopefully it'll be the same size a fair bit more powerful!
Purely for reference.
The Old 1988 DTR's with the code 3BN have the 56.4mm Barrel.
3MB barrels have a 56mm barrel.
Because they have a bigger bore it would mean a slightly smaller stroke. And thus will want a double base Gasket to compensate the smaller barrel if you fit a 3BN. KenDog has successfully fitted a 3BN to his 3MB setup.
To be fair I completely for forgot to double up base gasket but I doubled up the head gasket instead everything is running well and its quick I just need to get my power valve back I'm there!!
Honestly ****ed it up that's what I done, bairn wasn't well while I was doing the bike and I got the gaskets mixed up!!
Ill be doing it again sometime soon (ish)
Ken
Actually come to think of it I removed the extra gasket sorry my mistake I put 2 in at first as I was rushing but took it off so its running normal gasket set but ill throw in another base gasket once I get time
