won't start

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RZjack
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won't start

#1 Post by RZjack » Sat Sep 23, 2006 5:14 pm

I'm a new member and I can use some help. It will not start, even though everything shows good on my VOM. The bike came safety wired so I assume it was raced at some point in it's life. With battery power the lights, turn signals and servo all are active. The cylinder compression is around 100. The carbs were cleaned. I have 2 open female connectors, 1 black the other blue/red, they are included in the leg of the harness that goes to the headlight and the turn signal unit. Can anyone tell me where they connect, and can this be the problem? :???:

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hybrid
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#2 Post by hybrid » Sun Sep 24, 2006 8:19 pm

Do you have spark?

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Andrew
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#3 Post by Andrew » Mon Sep 25, 2006 6:28 am

When you first switch on, does the power valve servo motor operate?

And again...

Do you have a strong spark on all 4 plugs???
Andy (UK)
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Faster Faster !!!

RZjack
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#4 Post by RZjack » Mon Sep 25, 2006 8:19 am

Yes the power valve servo does operate when the switch is turned on. As for checking for spark, this has been a problem. Can anyone recommend a tool to monitor spark while kicking over a 2-stroke. Previous machines have had electric starters and it was easy to hold the button and ground the plug.

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Andrew
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#5 Post by Andrew » Mon Sep 25, 2006 9:08 am

...just hold the spark plug and give the bike a few good kicks... you'll soon know if the plugs firing... :shock: :shock: :shock:

Seriously, get a friend to help you.
Take all the plugs out (after numbering them according to the cylinder numbers), ground the plug on the motor or framework (you should be OK by holding the supressor cap, but if in dout, use a good insulated set of pliers) and let your friend sit on the bike and kick it while you keep an eye on the spark, you should see a good strong spark. do one at a time...
Andy (UK)
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Faster Faster !!!

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#6 Post by RZjack » Wed Sep 27, 2006 8:28 am

I have checked and I have spark. So now the bike has spark, compression and fuel and still won't start, not even a pop. This would lead me to timing. I will be getting into that next. As I mentioned the bike was safety wired and I believe it was raced. Has anyone come across ex-race bikes and know of any timing changes a tuner would make?

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#7 Post by rd84 » Wed Sep 27, 2006 10:09 am

Hi,

Its common to advance the ignition - if you take the alternator cover off you might be able to see if the backplate has a slot filed into the bolt holes that locate it on the crankcase - however it should still start.

What about the chokes in the carbs - is that all serviceable ???

What about compression ??

Good luck

Cheers
Paul
RZjack wrote:I have checked and I have spark. So now the bike has spark, compression and fuel and still won't start, not even a pop. This would lead me to timing. I will be getting into that next. As I mentioned the bike was safety wired and I believe it was raced. Has anyone come across ex-race bikes and know of any timing changes a tuner would make?

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#8 Post by hybrid » Wed Sep 27, 2006 10:23 am

Maybe also check that the woodruff key isnt missing/broken allowing the stator to move.

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#9 Post by RZjack » Sat Sep 30, 2006 9:47 am

I went over everything again. I re-cleaned the connectors for the electrics. In looking over the fuel system I found one line was kinked, so I fixed that. The bike still won't start, but when I kick it ,I am begining to get some smoke from the pipes. I failed to mention that the bike had been sitting for about 6 years before I got it. Any suggestions or just keep kicking? My right leg is starting to get so over developed I'm walking in circles!

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#10 Post by Lynton » Sat Sep 30, 2006 5:32 pm

Do you know anyone with a set of starting rollers. Or get a "very trusted" friend to tow you behind a car

lynton

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#11 Post by Ken Smith » Sun Oct 01, 2006 12:59 am

Give this a go. Can most times get anything with compression and spark to run this way, even bikes with very low compression. Wouln't run long but at least you know it runs. Take off the fairing sides and lower pan. Remove the air box ears to expose the carb openings. Make sure you have good plugs installed (I'd be using cheep ones here and new) (A heat range of 8 will work out OK for this, even 7 will not hurt for a short time just don't rev the engine to high, just using the 7's to help get things going, then go to the 8's )Next get the tourch,(if in UK this is not a flash light) give each carb a shot of gas then give a few kicks. If no fire give another shot of gas, (not to much) then kick and give a shot of ox. This should fire it up. If no tourch starter fluid will work also, again not to much. Also it's best to do all this out side away from buildings. Sometimes fire shoots out the carbs. (this is why not to much) This at least lets you know that it will run. With the bike sitting along time several things can happen. The check valves on the oil pump may have leaked two stroke oil in to the crankcases, this will most likely faul the plugs. I'd have a set of cheep ones installed till it gets running a bit better. this may take a set or two of plugs. Also the rings may have stuck, once running a bit try Ring Free. You can buy this from Yamaha dealers it's one of their products. Have had very good luck with this and all you do is add it to the fuel. Also check the pilot jets for dirt again and again till it starts to run. Sometimes still dirt in the fuel lines. (I uasally install new ones on a bike that has been sitting that long) Check the fuel tank for dirt and rust, not just buy looking into it and seeing a clean tank. Try rubbing your finger on the inside top of tank, this is many times were the rust is!! Rust falls down in to fuel even though the tank looks clean. Again Yamaha sells a great tank cleaning probuct. I wouldn't play around with the timing at this point. It's hard to move it enough to get to the place were it wouln't run so probbly not that. If it's a 84 47X on the CDI have had them get intermitent spark and would show spark only to disapear a bit later. Could nead a CDI.

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#12 Post by RZjack » Mon Oct 02, 2006 8:22 am

It started! It put out smoke like a Cheech + Chong movie, but it started and I was able to take it up the street and go thru the gears.I would like to thank all the members who helped me with tips and information. There's always the risk and mystery when you buy a machine thats a non-runner. But with members like this group has it's nice to know help is always available. Thank's again! Jack. :grin:

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#13 Post by hybrid » Mon Oct 02, 2006 7:56 pm

Good stuff RZJack :)

So what do you think was the major cause?

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#14 Post by RZjack » Tue Oct 03, 2006 8:47 am

The pinched fuel line was probably a factor. It would flow fuel when the tank was lifted, but pinched when down. I am using regular fuel line from an auto parts store, I figure Yamaha's lines would be 21 yrs. old and kind dry and brittle. I installed new lines and wrapped it in the hard coiled plastic sheathing used for a car wiring harness, it seem's to have worked. The bike still does not start like it should. It seems to be rich, I had to loosen the air boxes from the carbs and lean out the mixture to start it. I will be replacing the 4 needle valve assm., because they all leak fuel and this might contribute to the over rich starting problem. On my short run it smoked badly and I noticed quite a bit of un-burnt oil on the exhaust tips. But it runs. So now it's just a matter of getting it to run better. Jack.

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