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Re:03 road star midnight star engine fail cant pin it
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TOPIC: Re:03 road star midnight star engine fail cant pin it
#1021288
G_Conway (User)
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Re:03 road star midnight star engine fail cant pin it 2 Months, 2 Weeks ago  
Like davej said, rollover valve could be an issue, causes a vacume in the tank that the pump has a hard time overcoming. If it's hard to pull the tank cap off, rollover is probably bad.

As others have said, fuel pump should only run for a few seconds with motor off. If it keeps running much longer than that, it could be failing to build pressure.
 
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#1021593
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Re:03 road star midnight star engine fail cant pin it 2 Months, 2 Weeks ago  
well bad news had to have bike towed home the other day. vented my gas cap sunday hoping to end my problem finally with the stalling. went for a test drive got about 5mi on the freeway and stall same thing as in the begining pulled over was able to start just like all the other times went about 1 mi stalls again. as mentioned since the begining every couple of times the start button wouldnt work all lights leds worked no dimming, well this last stall start button didnt work and hasnt since.
so here i sit tank off and not having any previos knowledge with this problem have my service manual out ready to start from the beggining check continuity , swithes ect on down the line. battery is wear its supposed to be. damn this is alot of stuff to check, with my thinking i should start at the starter switch on my handlbars then the starter remember battery is good, lights on and bright.

does anyone have a shorter/more direct check list for this problem? anyone got a good starter thats collecting dust and is just always in the way taking up space? the thing your wife always points at saying "if you got rid of some of this junk you would have more room/would look better in here.lol
 
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#1021598
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Re:03 road star midnight star engine fail cant pin it 2 Months, 2 Weeks ago  
Im in Mira Mesa. Willing to try and help if you want. I don't have spare parts, but I may be able to help you figure this out.
 
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Re:03 road star midnight star engine fail cant pin it 2 Months, 1 Week ago  
Fuel starvation will usually give you at least 10 seconds of stumbling before it dies...Eliminate fuel delivery first(easiest)...wouldn't be surprised if its not ignition or a power supply problem to the ignition...possible pick up coil.
 
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#1021952
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Re:03 road star midnight star engine fail cant pin it 2 Months, 1 Week ago  
He actually had multiple problems.

The engine was dying from an intermittent kill switch (which finally stopped making connection at all, so wouldn't turn over.) Cleaned up switch and now cranks fine.

He has a few weird issues:
His fuel pump seems marginal at best (put mine on it to confirm.)

The plastic "valve" in the carb was frozen in place (burn / melted spot about the size of a quarter on the manifold side.) Looks like severe backfire or flame at some point. Filed it back smooth-ish and at least it move freely now.

I think he also has a bad case of SVS on the rear jug exhaust. He removed the pipes and is giving them a heavy Sea-Foam bath.
 
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#1021976
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Re:03 road star midnight star engine fail cant pin it 2 Months, 1 Week ago  
"Plastic valve"= slide?

Good on ya, btw.
 
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Last Edit: 2017/09/11 18:54 By SKWEARpeg.
 
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#1021977
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Re:03 road star midnight star engine fail cant pin it 2 Months, 1 Week ago  
SKWEARpeg wrote:
"Plastic valve"= slide?

If you look at the Yamaha parts breakdown, they call it a "valve."
 
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#1021978
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Re:03 road star midnight star engine fail cant pin it 2 Months, 1 Week ago  
G_Conway wrote:
SKWEARpeg wrote:
"Plastic valve"= slide?

If you look at the Yamaha parts breakdown, they call it a "valve."


The plastic thingie attached to the upper diaphragm, that goes up and down with the flow of air through the carb throat?
 
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#1021980
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Re:03 road star midnight star engine fail cant pin it 2 Months, 1 Week ago  
SKWEARpeg wrote:
G_Conway wrote:
SKWEARpeg wrote:
"Plastic valve"= slide?

If you look at the Yamaha parts breakdown, they call it a "valve."


The plastic thingie attached to the upper diaphragm, that goes up and down with the flow of air through the carb throat?


Yes. Most here call it a slide; however, the service manual refers to it as a "piston valve."

I don't write em, just read em.
 
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Re:03 road star midnight star engine fail cant pin it 2 Months ago  
UPDATE: First would like to make a suggestion we need a hall of fame board, with awards like best help ending in a started rolling bike, ect..
Came up with this idea while sitting with G_Conway in-person! trying one thing after another, ripping this off putting it back on from 10am to 7;30pm. Then i had to insist that we find out some way to get his bike up the hill to my place so we can get it back on the road so he can get home. Oh ya i forgot to mention when he got to my place down the hill from it he busted his clutch cable damn that woulda spoiled my day for anything especially fixing someone elses bike.Got it up there and went inside to get us something to eat and i'll be damn if he's not pullin parts off his bike to narrow down the problem. Well anyway when ya see him on here tell him "way to look out" or shake his hand or a pat on the back i did.

Update: 1. Turns out problem was a combo of things a) faulty (intermitant) fuel pump. Have gone pumpless. b) Short in the kill switch . Able to clean up contacts fixed. Think this was main problem all along.

So we start it up takes 1 or 2 trys bingo we have ignition, then BANG rear jugg has a back fire big time. So for the rest of the night i start soaking what we can see of the exhaust valve with pipes off useing seafoam spray hoping i dont have bent or stuck valve. Next day start up again the backfire.

So at this time am preparing to do compression check.

Questions reguarding pumpless: 1. I know i have to replace needle and seat to a 2.5 is this size correct?
2.Also have to reset the float to 4 mm above where bowl mates to carb (service manual states 2mm below where bowl mates to carb have read on here that serv manual is wrong). Is 4mm above mate line right?
3.I have fuel filter in vertical position, arrow on filter going the right direction. Filter sitting reguarding height in between tank and carb. Is vertical position ok?

Ok problem at hand backfire: Starting at compression test. As i understand i have to remove the decompression selinoid before test , do i have to drain my oil first? Or is this compartment oil free? And is there a gasket? Sorry dont have my repair manual with me.

And does any one know the protocal/order to hunt this backfire down?
Thank you in advance for your help
 
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