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Cam chain tensioner or something worse?


nicksta43

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Fuel leak is fixed. Apparently I, for some unknown reason, loosened the fuel rail bolts and forgot to tighten then back. When it loosened enough it split the o ring on the #1 injector. I happened to have some that fit so that was an easy fix. 

Unfortunately I still have a problem. It's still tough to start. It will idle roughly for a couple seconds then rev up to about 2500 rpms for a second or two then settle down into a normal idle. It'll rev freely but the exhaust stinks. It's much more pronounced but the same oder I thought I was smelling the week prior to this all starting. 

I took it out for a test ride. Under light loads it feels just like it always did. However under a heavy load it bogs. Roll on the throttle in sixth and it'll gain about 500rpms then bog,  it'll rev through it but it's slow and it's not rpm dependant. 

I think tomorrow I'll take it back apart and do a compression test now that I know nothing is actually hitting anything internally.

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Compression is way down on all cylinders.  70 on 1 and 3 dry and wet, 2 was 60 dry and 65 wet. 

This is a concern because the valve clearance on #2 was in spec. 1 and 3 were a little tight. 

I guess the next step is to get the valve clearances in spec then check again. 

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It's probably been mentioned before, but for accurate compression test results, the engine should be hot and the throttle valves (butterflies) should be wide open while spinning the engine to get the compression readings.  I don't know if  failing those conditions would account for  a 100 psi difference between  spec reading and your readings, but thought I'd throw it out "in case".   And frankly,  your engine sounds so crisp and tight both idling and  being  run up,  I don't see  low compression as a problem.

The  "stink " and wildly varying engine speeds are almost certainly a fuel and maybe vacuum problem - and that is almost certainly an electronic issue.   IMO,  before taking the head off,  take it  to a motorcycle shop having the tools to  read the fault codes and know what they mean and how to fix them.

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@nicksta43 - Do you still have the stock exhaust on your bike?   Some of the symptoms you’re describing sound a lot like a plugged catalyst to me...  I had that happen on my Ford truck, and had the same weird smells, inconsistent idle & performance under load, etc.    I’m not sure  how it would impact compression readings,  but intuitively I can see how it might...  plugged exhaust would inhibit scavenging of the exhaust gas after the compression cycle.  

I agree with @justplainbillthat it sounds too crisp to have a major compression loss problem.    

Just my $0.02.  Take it for what it’s worth 

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1 hour ago, texscottyd said:

@nicksta43 - Do you still have the stock exhaust on your bike?   Some of the symptoms you’re describing sound a lot like a plugged catalyst to me...  I had that happen on my Ford truck, and had the same weird smells, inconsistent idle & performance under load, etc.    I’m not sure  how it would impact compression readings,  but intuitively I can see how it might...  plugged exhaust would inhibit scavenging of the exhaust gas after the compression cycle.  

I agree with @justplainbillthat it sounds too crisp to have a major compression loss problem.    

Just my $0.02.  Take it for what it’s worth 

If the back pressure is all wrong, it could totally effect compression. 

For example: if there is too much back pressure on the exhaust stroke, the pressure in the cylinder will be too high on the intake stroke messing everything up. You might be onto something Scott.

'15 FJ09

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3 hours ago, justplainbill said:

It's probably been mentioned before, but for accurate compression test results, the engine should be hot and the throttle valves (butterflies) should be wide open while spinning the engine to get the compression readings.  I don't know if  failing those conditions would account for  a 100 psi difference between  spec reading and your readings, but thought I'd throw it out "in case".   And frankly,  your engine sounds so crisp and tight both idling and  being  run up,  I don't see  low compression as a problem.

The  "stink " and wildly varying engine speeds are almost certainly a fuel and maybe vacuum problem - and that is almost certainly an electronic issue.   IMO,  before taking the head off,  take it  to a motorcycle shop having the tools to  read the fault codes and know what they mean and how to fix them.

The engine was ran up to Temp before I pulled it apart to get to the plugs so while not hot it was definitely warm. I unplugged the throttle motor and held the butterflies open by hand. 

It has no fault codes. 

I'd love to take it to a shop and just have them fix it. I don't have the money for that.

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2 hours ago, texscottyd said:

@nicksta43 - Do you still have the stock exhaust on your bike?   Some of the symptoms you’re describing sound a lot like a plugged catalyst to me...  I had that happen on my Ford truck, and had the same weird smells, inconsistent idle & performance under load, etc.    I’m not sure  how it would impact compression readings,  but intuitively I can see how it might...  plugged exhaust would inhibit scavenging of the exhaust gas after the compression cycle.  

I agree with @justplainbillthat it sounds too crisp to have a major compression loss problem.    

Just my $0.02.  Take it for what it’s worth 

I'll have to see about determining if the converter is bad.

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6 hours ago, nicksta43 said:

The engine was ran up to Temp before I pulled it apart to get to the plugs so while not hot it was definitely warm. I unplugged the throttle motor and held the butterflies open by hand. 

It has no fault codes. 

I'd love to take it to a shop and just have them fix it. I don't have the money for that.

Perfect! 

I didn't know you had checked for codes. Taking it to a shop with no fault codes just puts the burden on them to  look for the problem and that generally involves replacing parts until the problem goes away.  Save your money.   

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I decided to check for any possible vacuum leaks. I couldn't find any but I took the opportunity to get a hot start video. So here is that.

I agree that it doesn't seem to run like it's missing that much compression, if any. 

I'm not sure what to do. 

Maybe the best thing would be to just suck it up and open up a credit card, take it to a shop and tell them to make it right. I really don't want to do that but I think I'm not up to fixing this. 

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That is strange... Kind of makes me think fueling or timing (spark plug timing) issue. Does anybody know where the crankshaft position sensor is? Has that been looked at? Have you taken the stator cover off and had a look in there?

'15 FJ09

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19 hours ago, nicksta43 said:

 

I'm not sure what to do. 

Maybe the best thing would be to just suck it up and open up a credit card, take it to a shop and tell them to make it right. I really don't want to do that but I think I'm not up to fixing this. 

I admit to being electronically illiterate, so if a "bad running" engine doesn't have carburetors, points & coil ignition (or magneto) then my first response is to blame the f'n computer.  I don't know if it makes sense to take the ECU to a dealer or even to one of the vendors here who re-map computers,  for testing and diagnosis, but that might be a possibility.  Even better, if there is a forum member living near Nicksta43 in Texas willing to lend him an ECU  to swap in for a test, that could be helpful.  Or a longer distance good Samaritan,  with a bike apart for some other purpose, or snowed in for the next month...  

Current asking prices for used ECU's on eBay are between $160-250.  Actual selling price for a stock one (from eBay completed auctions) was $92 in Nov.2018.  Obviously these are NOT high demand items, so a best offer might work out.  It might not be worth the gamble to buy one outright...but maybe a seller would be willing to "sell" one and charge a re-stocking fee ($25 to $50?)  if that isn't the problem and his ECU is returned in same condition as sent.     

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2 hours ago, justplainbill said:

I admit to being electronically illiterate... 

I bet I am more electronically illiterater than you, jpb!

Riding a fully-farkled 2019 MT-09 Tracer 900 GT from my bayside home in South East Queensland, Australia.   

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