1kt 2MA What are the differences ?

[steveof]

Hi,could anybody tell me the differences between the 1KT and 2MA Frames and engines or are they the same...Thanks .Steve

[teezer250]

Engines and frames are the same.
There are 2 types of swingarms and linkages,one takes a shock with eye-eye mountings and the other takes eye-fork mountings.
The electrical connector blocks from the engines are different.

[steveof]

Thanks again teezer 

[nronketti]

Not strictly an engine difference, but the plugs from the pickup and stator are different. Easy enough to fix if you need to, but if you mix a 2MA loom and a 1KT engine or the other way, you'll need to do a bit of crimping and soldering to make the connections.

[ypvs250]

the differances are 1kt to 2ma ,loom/cdi and some connectors,clock bracket ,frame finish ,shock/swingarm linkage depending if early or late

[mboddy]

1Kt engine cases have a smoother internal finish around rear transfer port and side case states smaller gearbox oil quantity.

[teezer250]

1Kt engine cases have a smoother internal finish around rear transfer port and side case states smaller gearbox oil quantity.

The early clutch cover had 750cc for the oil quantity,I've seen one on ebay a couple of months ago.
Both my 1986 1kt's have 1000cc cast into the cover.

[tzr-v4]

1Kt engine cases have a smoother internal finish around rear transfer port and side case states smaller gearbox oil quantity.

The early clutch cover had 750cc for the oil quantity,I've seen one on ebay a couple of months ago.
Both my 1986 1kt's have 1000cc cast into the cover.

Yes but I've seen additional plate bold on clutch cover to mask the 750cc and to show 1000cc.

[TodS]

I see the 1KT was limited to 45 HP, how did the 2MA get 5 more HP?

[SeaR1ck]

I see the 1KT was limited to 45 HP, how did the 2MA get 5 more HP?

1kt is Japanese market bike so laws limited bikes to 45hp stock. 2ma is the euro spec where the 45hp law was not a thing. So the 2ma has the better mapping. If you have a 1kt you can't just simply get a 2ma cdi. The two bikes wiring harnesses differ.

[m in sc]

you can however fit a zeeltronic and remap it, which is what i did to mine. also I luckily have the non restricted stock exhaust 

[TodS]

you can however fit a zeeltronic and remap it, which is what i did to mine. also I luckily have the non restricted stock exhaust 

Which models have the stock non-restricted exhaust?

[tzr-v4]

I've put on the French RD500LC Club web some picture of my 2XT

TZR 2XT

Ring restriction
Exhaust

Not sure these rings were on 1KT or 2MA pipes.

[James P]

Which models have the stock non-restricted exhaust?

As far as I can tell, all 1KT-based TZRs had the same exhausts, except for the 2XT. As Olivier mentioned, 2XT exhausts had restricting rings welded in, along with a thicker head gasket and a more conservative ignition characteristic. These restrictions were seemingly intended to negate the (potential) performance improvements offered by the upgraded cylinders and reed valves fitted to this model so that its output would be about the same as the preceding 2AW model.

On the topic of the JDM 45ps limit; I have gained the impression that this was rather more of a rough guideline than a hard-and-fast enforced rule. It seems to me that there were not enough differences between JDM and export 1KT-based TZRs to account for a consistent 5ps difference - I think the power output difference was only on paper (the quoted figure being stated so as to suit the market for which a particular model/version was intended).
It seems that the manufacturers put in a little more effort with the later 40ps limit, but again it is only an impression I have gained.

Of course, if anyone is in a position to carry out consecutive (and thus comparable) dyno runs using low-mileage pristine-original-condition examples of both JDM and export 1KT-based TZRs, then we'll all know for sure!

Regards,
James

[m in sc]

mine was a stock 1kt and had the original pipes, they were not fit with the ring as stated above, ever. (just a data point.) TBH. that was one of the 1st things i checked when i got it not being as familiar w them at the time.  I also set the squish to 0.8mm when i refreshed the top end (was only at 5200km at time but did it out of preventative) and have been quite pleased with the result.