93' exup cold start probs!

[phildekked]

Just bought a 93' exup to replace my ageing 88 Genesis and am getting worried I've bought a lemon! <br><br>It just won't cold start , you can turn it over till the battery's flat and it just won't go. Using a jump start it'll go after a few minutes starting very lumpy on two cyls' then all four after a minute....<br>I've cleaned the carbs ( properly with an air line twice ) , checked the fuel pump ( working fine ) , checked the in-line filter ( clean ) , checked primary and secondary coil resistances ( all in tolerance).<br>, replaced plugs with a new set.......<br><br>So I'm a bit baffled , it seems the coils are ok and usually they break down as they warm up ! The carbs are spotless and not overflowing and levels are ok , there is a smell of petrol as it turns over so it kinda points at ignition...<br><br>Its a continental model with the headlight on always ( a pain in the neck as u have to disconnect when trying to give max turning over !), so is there any change in the ignition wiring ?<br><br>I've read on other posts about ignition switch corrosion , would that affect cold start only ?<br><br>Forgot to mention once it's running it runs fine and will re-start on the button !!!<br><br>Any other ideas for me to try .....!<br><br>phil <p></p><i>Edited by: <A HREF=http://pub28.ezboard.com/bexupbrotherho ... ldekked</A> at: 12/23/03 2:48 pm<br></i>

[ChuckD]

I find that if valve clearances are out of spec, it makes hard cold starts, even if they are close, it could affect it. I suggest checking compression to rule out that possibility. Also check the ignition switch plug end and see if it's melted, common. And the same goes for the alternator plug, it gets hot and toastey too. Still nothing, let us know and maybe some more ideas will come up.<br>CHUCK D. <p></p><i></i>

[exup boy]

hi phil ive got a 1990 exup i recently went throght the same thing it runs sweet whem hot no "rattles" nothing but cold start a $$cking nightmare so i got my mechanic to have a look(before i burn the starter out) out of 20valves i had 18 that needed changing now she starts sweet i hope this helps<br>regards bill<!--EZCODE EMOTICON START :hat --><img src=http://www.ezboard.com/images/emoticons/pimp.gif ALT=":hat"><!--EZCODE EMOTICON END--> <p></p><i></i>

[phildekked]

Well its looking like the valves ( or the cylinders !!!) are losing compression . I`ve been through everything else and had a chat with me favourite ( very helpful !) mechanic. <br>He came to the same conclusion and related a story about a GSXR 1100 which was a bitch to start and that was all down to valve adjustment ( as it was his drag bike he managed quite a few more horsepower after adjusting!).<br>Anyway gotta go earn some money to afford the cure ( my man also said he hated working on exup`s as it was so crammed and everything is tiny in the head !)....<br><br>I`ll let ya know <br><br>phil <p></p><i></i>

[phildekked]

Well it works ! Had the valves done a few weeks ago and the thing starts now ( even in the British winter !) . The inlets on all four cylinders had no clearance and the exhausts were out on two ! Couldn`t afford a full head-off, re-lap so it`s gonna wait till next winter ( hopefully with a gas-flow and big-bore!).<br>Took out for a first real thrash yesterday and it has made a vast improvement to the midrange as well with loads more torque around 4/5000 rpm...?<br>Anyway another problem .........>>!<br><br>It hunts on tickover between 1000 - 1500 rpm , doesn`t seem related to temp as it does it straight after warm-up and if it`s real hot ( my old Genesis does the same but i put that down to a straight thru race pipe ) . Any ideas , is it just throttle cable or tickover screw looseness, or something deeper...?<br><br>.p. <p></p><i></i>

[Cosmo007]

The exup may be out of adjustment, which could cause some odd backpressure issues at idle. Just an idea but how what is the condition of the pilot jets? <p></p><i></i>

[phildekked]

Well found the prob...!<br><br>The oil drain on the left bottom of the air box had a crack ( which turned into a broken stub !) and this was letting air into the filter side of the box .<br><br>Bit weird but i was sure it was carb rubber , inlet tract problem so checked all bolts and clips on the carbs as well<br><br>ticks over fine now...!<br><br>phil <p></p><i></i>