KZ750 N1 Spectre Won't Start

Okay, I'm new to site and I'm sure I'm gonna get burned on this but I just put my KZ 750 back together after replacing the head gasket, valve adjustment, and new carb diaphragms. I also cleaned the carbs too while I had them off. I'm getting good compression on each cylinder (160-180). Because of this I'm thinking I got the timing right. I cleaned the petcock and now have good fuel flow. There is fuel in each bowl. The battery is six months old and has never ran on the bike but I have tried to charge it periodically. I tried starting fluid and got nothing. I can see spark on all plugs but I'm now suspecting the battery. I'm trying to come up with a good method for troubleshooting this and I really want to get it going myself. Also, put on new 4-1 exhaust but I'm waiting on header gaskets. I just assumed it would leak a little but I could still get it to start.

I know that's a lot of information and probably my methods are suspect but any help is appreciated.

Jordan.

jjackson7 wrote: Okay, I'm new to site and I'm sure I'm gonna get burned on this but I just put my KZ 750 back together after replacing the head gasket, valve adjustment, and new carb diaphragms. I also cleaned the carbs too while I had them off. I'm getting good compression on each cylinder (160-180). Because of this I'm thinking I got the timing right. I cleaned the petcock and now have good fuel flow. There is fuel in each bowl. The battery is six months old and has never ran on the bike but I have tried to charge it periodically. I tried starting fluid and got nothing. I can see spark on all plugs but I'm now suspecting the battery. I'm trying to come up with a good method for troubleshooting this and I really want to get it going myself. Also, put on new 4-1 exhaust but I'm waiting on header gaskets. I just assumed it would leak a little but I could still get it to start.

I know that's a lot of information and probably my methods are suspect but any help is appreciated.

Jordan.

...good compression...tried starting fluid and got nothing...can see spark on all plugs.... -- would suspect ignition timing; perhaps the advancer is 180° off.

Good Fortune!

Hmm. How do I check/fix that? Do I need to go back to square one here? I tried to follow the Haynes manual to the letter and all I remember it saying was that I needed to set the crankshaft to the '1-4' mark when I reinstalled the camshafts and timing chain. Did I miss something here?

Thanks,

Jordan.

Would follow static ignition timing procedure shown in the manual to assure cylinders 1 and 4 will fire when the F mark for 1 and 4 aligns with the case mark.

Some samples of the marks:


The T mark is used incident to cam timing.

Good Fortune!

agree also could pull number 4 sparkplug and rotate crank to 1/4 cylinder f mark and watch for the sparkplug to fire.

Did you rejet the carbs when you placed the 4 into one exhaust? Are the plugs dry?

I will work on checking the timing this afternoon. I did not rejet the carbs. Thought I would be able to get it started and then tune from there.

The plugs were not wet when I pulled them to check for spark. Not a good sign huh? I should note that the diaphragms I changed were not OEM. I had to cut the old ones off the slide and add these. The action on the slide seemed good when I was done and could hear some air movement. The carbs were adjusted and working the last time the bike ran.

I started this process because the head gasket started to leak so bad that it wouldn't start and I knew the valve adjustment was due anyway. The previous exhaust was cracked at the crosspiece so decided to replace that too. I hate making this many changes at once but decided it needed all this while it was apart.

On a side note does anyone have a good method for refitting the rubber boots from the airbox to the carb. So far that has been the most irritating part of this repair and I dread pulling the carbs again because of it.

Thanks,

Jordan.

New carb boots are the recommended choice when replacing torn/ripped ones. If money's tight, try soaking the old boots in very hot water to soften them up.

Here's another method of rubber softening:



Successfully Resurrecting Old Rubber Parts
(Found on the internet)

This subject has been broached before but the author is happy to report success in revitalizing old rubber.

The author have been using a mixture of 30% wintergreen oil (methyl salicylate) and 70% xylene to restore old rubber parts and it works beautifully. This is the same ingredients and proportions for the commercial product Rubber Renue according to the MSDS sheets.

Wintergreen oil is analgesic and liniment for aching muscles and found in most drugstores, pharmacies, health food stores and co-ops.

He gently heated rock hard honda CB carb boots with a heat gun for 30 seconds and dropped them into mason jars with my solution for 12 hours at room temperature. They come soft, pliable and looking good. They have been out of solution for 48 hours now and are still soft and pliable. He soaked smaller rubber parts such as side panel grommets and there extremely soft and may need to soak for less time

When I suspect the battery, I bust out this one:

THIS IS A CHEAPAZZ PORTABLE BATTERY STARTER, IT 100% DE-MYSTIFIES WHETHER THE BATTERY IS THE PROBLEM



I would definitely take Patton's advice though if you've had the head off.

If you have one of these portable jump starters you can eliminate the battery as the source of your non-starting problem in 10 seconds.

Cool I'll try the hot water first then try solution. The boots are in good condition. There is just limited space between the carbs and airbox to work. I ended up putting the boots almost completely in the airbox, mounting the carbs in the intakes, and then pulling the boots out working with one hand in the airbox and one working from the outside. I think the whole process took me about an hour of cursing and thinking there had to be an easier way.

I read back over the manual and my notes and I did line up with the 'T' mark when I was refitting the camshafts.

I'll try to work through some of this tonight and report back.

Okay. I checked timing by pulling a plug and turning the crank and timing is right. I had the battery on the charger all morning and when I tried to start it again it ignited a couple times (like a weak cough). I'm gonna track down a portable battery jumper and check it out. I'm hoping it's that simple.

Maybe jumper cables from a car battery that is not on a running car- be careful. is the fuel line pinched? it has happened to me alot. have you set the petcock to prime?