Running Engine that doesn;t run any more.

[Anonymous]

I had the darn thing running and with it running I messed with the pilot screws now it doesn't start. It trys to start but no go. I put the screws back to where they were originally and it didn't help any. At a loss on what to do.
I am getting a nice blue spark, have a brand spankin new battery, new R/R, stator omhs out correct, cam at TDC is in the correct position, carbs were rebuilt during engine rebuild, float level is good, fuel in both bowls, valve clearances are with in spec, and compression is good. Gone through what the Suzuki shop manual says for no start and every thing checks out. The plugs are wet with gas when I pulled them.

It is a 85 450A (GS450GAF)

[Poot]

the needle jets got stuck on my 850, which prevented it from starting, but there was no fuel in 3 bowls.

the only thing i might suggest, is to clean out the pilot circuit in the carbs, as that usually helps with starting issues, although you have cleaned them out already.

:?

[redliner1973]

Make sure your petcock is not set at 'prime'. sounds like your flooding it out.

[Poot]

to check for petcock issues, just drain the floatbowls, and then give it a crank , and see if any fuel is going through the lines. should take less than a minute to fill up the bowls.

[KEITH KRAUSE]

Quick thought: Did you play with the ignition timing at all? Is everything tight? If loose, it may have moved when started.
If not, I would try a good bench synch followed by a vacuum tool synch.
Since you say you have gas in the cylinders and a good spark, I have to think you're not getting enough air. A poor carb synch will cause your problem.
I assume the air filter is clean?

[Anonymous]

Pulled the carbs dipped them, replaced o-rings, bench synced them, and still no luck starting. I do not have the tools for a vacume sync just yet. The timing as far as I can tell is good, how can you check to make sure it is firing at the correct cylinder position? I currently have the piolt screw set at 3 turns out, is this a good starting point? The float bowls fill just fine. The petcock is set on "Run".


How well would this sync tool work?

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=25623&item=7968865770&rd=1&ssPageName=WDVW

or this one?

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=4542976278&category=43998&sspagename=WDVW

[KEITH KRAUSE]

Did you turn up the idle adjuster knob enough after bench synching the carbs? Any chance you have an intake leak? Did you replace any manifold o-rings? All boot/manifold clamps tight? The mixture screws are generally about 2 turns out on a stock bike.
I didn't look at the carb tools, but the Morgan carb tune is a great tool. A less expensive tool such as Motion Pro mercury tool, is what I use. It's simple, but accurate (if you are). Mercury tools are subject to condensation effecting the levels, but this is usually only a minor problem caused by taking too long to synch and turning off the bike during the synch. Condensation mixes with the mercury. The Morgan tool uses metal rods.

[Anonymous]

Bought the Motion Pro Carb Synchronizer today. Does the bike have to run before you can vacume sync the carbs? I did turn the idle screw in, no leaks, clamps are tight and secure. After the rebuid I did notice that the plugs were not near as wet with gas as they were before the rebuild. But still doesn't start it will try to but never does.

[dgeorge]

Jay when you did the engine rebuild did you also do anything to the cam chain tensioner? When I rebuilt my top end last year, I also rebuilt the cam chain tensioner and forgot to release it once I put it back in. The bike ran for a few minutes then jumped time one tooth and would not start again. Make sure that this has not happened to you. I burnt up my starter trying to get it to start while it was out of time. I'm not sure what your timing is like on the 450, but on mine it was a real pain, because the manuel was not clear on how the arrows should line up. Hope you get it going.

[Anonymous]

I did remember to release it tensioner. I have checked to make sure the arrows line up correctly on the cams.

[KEITH KRAUSE]

Bought the Motion Pro Carb Synchronizer today. Does the bike have to run before you can vacume sync the carbs?

The bike has to be warmed up and on the centerstand. The ignition timing must be correct too. A good bench synch will make the vacuum synch quicker/easier.

[Anonymous]

Put the pilot jets at 1.5 turns each. Made a bit of a diffrence but still no running engine. If I take gas and put it in a Windex bottle and spray it into the breather it almost will start but never does. I am beginning to wonder if my gas is bad. Going to drain the tank/float bowls and put fresh gas in and see what happens. This is beginning to get personall between me and the bike.

[Detman101]

Did you pull your sparkplugs and clean them yet?
You mentioned that the plugs were covered with gas and that may keep them from firing right.

It always helps to have clean parts when testing and retesting.


Dm of mD

[Anonymous]

Well I did manage to make progress today. I have the piolt jets out 1.5 turns out, drained the carbs and tank, took the petcock apart and cleaned it up with carb choke cleaner, and put fresh gas in the tank. I pulled the petcock off my 450S b/c I don't know how to get the other one back together right. I managed to get it started, but I have the throttle 1/4 open and it bairly stays running. There is a slight diffrence in engine speed between 1/4 throttle and full throttle but not much. I am thinking it is an issue of not enough fuel/air.

How do you put the little white plastic selector back in the petcock assembly. There is a sort of metal spring thing that pushes down on a valve the connects to the vacume line side of the petcock. After putting mine back together it isn't as easy to turn as it was before. I don't think I have selector in the right positon.

[Anonymous]

Well got it running again finally. Ran it for a bit and noticed bad noises comming from the engine so I drained the oil and had metal shavings. So I pulled the engine and torn it down all the way (this will be the 2nd time I have done this). I noticed that the crankshaft had some play in it and was banging on the case. Bought a thicker spacer and that solved that issue. Now to reassemble the engine and hope this will be the last complete tear down. Also firgured out why it would slip out of "High" gear (it is an automatic).