Trav Posted July 26, 2010 Share Posted July 26, 2010 Hey, I've got a friend who's 1980 XS400 SG model with an engine that's got oil full of metal. The easiest and cheapest would be to swap in a good engine, and we've found one. However, it's the more "squared off" version (don't know what year) and I'm betting it's not electronic ignition. This will be much simpler than adding transistorized ignition to a points model, as all the stuff is there... I just need to know if the head and the cam are the same as far as if the bits just bolt up. Thanks! Link to comment Share on other sites More sharing options...
kmac Posted July 27, 2010 Share Posted July 27, 2010 You should find out what year the engine is if possible. The first first 3 numbers of the the number stamped on the crankcase (1L9 for example) would be helpful. I converted my 78 xs400E which had points to use an electronic ignition from an xs400G. So upgrading an xs400 engine from points to electronic would be easy and only require removing the points and mechanical advance then replacing them with the pickup coil and rotor from the broken G engine. I would figure out what engine you actually have though. That said, if the pickup coil plate fits properly and the 2 coils physically occupy the same location as the points once did, it should work. The pickup coil plate from the electronic ignition engine should be exactly the same size (diameter) as the plate that holds the points on the new engine. Link to comment Share on other sites More sharing options...
exess4 Posted July 27, 2010 Share Posted July 27, 2010 Hey, I've got a friend who's 1980 XS400 SG model with an engine that's got oil full of metal. Hey The easiest and cheapest would be to swap in a good engine, and we've found one. However, it's the more "squared off" version (don't know what year) and I'm betting it's not electronic ignition. Squared off, you mean dohc (2 cams? overhead)? From an XS400? that'd be 82-84* Link to comment Share on other sites More sharing options...
armyofda12mnkeys Posted July 28, 2010 Share Posted July 28, 2010 Hey Squared off, you mean dohc (2 cams? overhead)? From an XS400? that'd be 82-84* Here is kmac's thread with all the part #'s needed ID you have a pre-80 model engine which im using as a reference (dunno why he would have a DOHC 82-84 model as i think they aren't points-based engines): I was debating putting the electronic ignition parts from a 81 to a 78 like kmac did, but I had a chance to get a full rebuilt 81 engine... so I put that in (have to swap the whole stator cover with the old one since it used 1 more wire), but the instructions should be the same. Working on splicing the ignition in soon. PS the only visual difference i see between an 80/81 and pre-80 XS400 is the points cover is thicker on the 80/81 Link to comment Share on other sites More sharing options...
Trav Posted July 29, 2010 Author Share Posted July 29, 2010 hm... don't some of the 70's SOHC xs400's have 'squared off' fins on the jugs and head as well? Say, like this 1977? At least the website I found it on using google says it's a 1977. His engine (1980 SG) is way more rounded than that, but otherwise appears the same. Here is a picture of the engine in question. The valve cover doesn't look like there are two cams in there to me, but what do I know. If it does happen to be a DOHC engine, would that be an amount of work and parts to swap in? I see it does have a mechanical tach, whatever it is. Link to comment Share on other sites More sharing options...
Moderator drewpy Posted July 30, 2010 Moderator Share Posted July 30, 2010 its a sohc, but not an SX the rounded barrels were fitted to the "custom" style bikes Link to comment Share on other sites More sharing options...
armyofda12mnkeys Posted July 30, 2010 Share Posted July 30, 2010 its a sohc, but not an SX the rounded barrels were fitted to the "custom" style bikes custom? like Specials? I was looking last night and see what he was talking about. Think my regular 78 and 81 engines have these rounded fins. Link to comment Share on other sites More sharing options...
Moderator drewpy Posted July 30, 2010 Moderator Share Posted July 30, 2010 custom? like Specials? I was looking last night and see what he was talking about. Think my regular 78 and 81 engines have these rounded fins. yep, heritage, custom, special etc Link to comment Share on other sites More sharing options...
Trav Posted July 30, 2010 Author Share Posted July 30, 2010 so... it'll work?! sweet. Another question was the electric start. It appears to be the same engine as the one in the picture of the '77, and that looks to me like it has a starter cover. Do the models that are 'kick only' have the option for a starter to be installed, if it happens to be without one? Link to comment Share on other sites More sharing options...
Moderator drewpy Posted July 30, 2010 Moderator Share Posted July 30, 2010 so... it'll work?! sweet. Another question was the electric start. It appears to be the same engine as the one in the picture of the '77, and that looks to me like it has a starter cover. Do the models that are 'kick only' have the option for a starter to be installed, if it happens to be without one? you would have to open the left case and stator off ( a pig of a job) and replace the stator case, buy a motor and wire it in. I personally wouldn't bother, there was only a couple of models which were kick only anyways, i think they ended in E as econony model and usually had wire wheels ( well sort after part now) Link to comment Share on other sites More sharing options...
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