ZXR250A not starting.. again..

Perhaps an instruction set available online once you have purchased the kit? With all the diagrams and collective knowledge on here though im sure i can do it.

 

Hey guys, the new carb seal kit arrived in the mail yesterday and I got stuck into it today. Got everything in and put it all back together relatively easily. Flicked the starter and she came to life running on 3 cylinders, 1 more than before I started ha. Changed all the plugs + oil and she now runs on all 4! Woot!

Just a few issues now though, the bike doesn't feel very crisp all over the rev range, especially when I give it the beans and hit 6-8k rpm. I think it's all to do with the pilot screw setting. Before taking them out, I screwed them all the way in and most were around 3 turns out. This seems more than usual, right? Also I checked my jets, 1 and 4 were 125, and 2 and 3 were 128.

Any more tips on how to get it revving cleanly?

Thanks again for the input as well, so much better with this info.

 

Cheers for the advice guys! Definitely has helped a lot! I'll double check for vacuum leaks tonight and I'll try and sync the butterflies also. I actually read what the pilot screw does, I now realize it doesn't have much to do with my troubles, silly me lol. I'll re-adjust to 2 and 1/2 or 2 and 3/4, whatever feels best.

Just to clarify, is there a difference between syncing and balancing the carbs? Is syncing just to do with the butterflies? I didn't touch the butterflies when I dismantled the carbs, but more than likely, some error has crept in between the four due to the disassembly so I'll be sure to adjust them properly.

Also, a quick question regarding zxr carbies,. When I re-assembled the carbies, I could only find 2 springs that go between the butterfly axle of each carb. These are not the adjustment springs, but the ones that just sit in between each pivot point. Logically there would be 3? Anyone have a full set they could double check for me? The zxr manual shows only 2, between carbs 1 and 2 and 3 and 4, but they diagram is crappy .. Just wanting to double check.

Cheers guys!

 

Today I removed the carbs again to try and improve the flat spots. I also adjusted idle screws to 2.5 turns out. I fiddled with the butterflies using the methods listed I think it did improve how the bike ran, but did not entirely remove all the hiccups.

When I first started the bike after all this it did not want to idle well at all, worst it's ever been. Twisting the throttle just stalled the engine instantly. I could maintain revs using the choke though. (I know this sounds normal, but it was way worse than compared to before the carb rebuild.) Once warm, she was fine. I think this was cured with a fiddle of the main idle speed adjuster which was completely out due to using it to set the right most butterfly as a benchmark for the other 3. I just got the feeling that the bike didn't want to rev from idle very well.

A work mate has kindly offered his carb sync tool of his, so hopefully I can get the bike a bit smoother. Winning!

Has anyone synced zxr carbs using a mercury type tool? It's my understanding that there should be ports on the carb to engine rubber boots to which you attach the 4 hoses of the tester. There are four hoses on the zxr carbs holder, one coming off each boot. They are interconnected and a single hose runs to the tank, are these the ports you are supposed to use? The manual states 'attach suitable vacuum gauge to pipes on the carb holder'. I know this is heaps obvious and a noob question and the answer is obvious, I just wanna double check haha..

 

Cheers again for the reply. So those four interconnected hoses on the boots come off, and the tester hoses go on?

I had them originally set at 3 after the rebuild. Now at 2.5. Might have been the cause of my shitty idle.. I dunno ha. I might set them to 3 again to double check.

 

I might do them up as much as I can and take it for another spin, just to cross it off the list. Yeah sure, I should have the tester over the weekend!

 

Got stuck into balancing the carbs today. Did them as best I could but still not perfect, will give it another go tomorrow. I did take some pics of before and after, will upload when I can. The carbs were out of sync a fair bit and being my first time, I couldn't get them balanced perfectly using the tool. Every time I thought I had them synced, gave it a rev and the gauges would be all over the place. Very frustrating that's for sure. I synced the left two then the right two, then the two banks together as per manual, which makes sense. I just found it difficult to balance one set without affecting the others, and a cramped work space just made it all the more frustrating. Blipping the throttle after each adjustment did help though.

The rev range was vastly improved after the balance, only giving me flat spots occasionally. It seems different throttle positions determine whether I have a flat spot, I should be able to nut that out with finer carb balancing, slightly out of sync carbs being the culprit I think.

One question, anywhere between idle and 3k rpm and the bike doesn't like being revved. Anything over 3k rpm and she revs straight off the bat. Would this be my idle screw adjuster? Currently its at 2.5 turns out but was at 3 turns out before I started. Like huntsman said before, trying 3 again may help.

Also while I'm at it, the Litetek kit was fantastic. Excellent quality and a worthy investment. I'm not sure whether its me imagining it or not, but the bike feels and goes absolutely bananas compared to before the rebuild. Two thumbs up for sure.

cheers again guys.