火箭三R中气缸压缩为零。有人知道原因吗？

[Mike188]

Welcome from South Australia.

 

[JAPANユーザー]

Your advice makes good sense. I see you have a Roadster, which I also did before the 3R, btw. You'd think the two would be very similar, and they are in many ways. But, I had to call on smarter folks here (credit to @Rocket Scientist) to understand why, when doing a valve check, the exhaust valves were so far out of spec. It turns out the de-compressors, which I was unfamiliar with, were to "blame."

I still don't think we have enough information to really help the OP, and given that it starts immediately and idles smoothly, I just don't think there's a compression issue, but something much more simple going on.

I'm about ready to step back until the OP provides a lot more information (and participation). I understand it's necessary to use Google translate, or something similar, but that is easy to do and doesn't limit how much information you can provide. For now....

Questions for the OP
When you did the compression test how did the plugs look?

Have you tried riding the bike? How does it perform? Is it fine at higher RPMs, for example?

Did you or the dealer do the 10k mile service? You're coming up on the 20,000 mile service interval which includes replacing fuel and air filters, spark plugs, valve check, and timing and throttle body adjustments.

Thanks for the feedback. I'm looking for a time to recheck for leaks. Because the engine isn't working properly, I'm afraid to try high revs. However, when I open the throttle, it stalls.

 

[JAPANユーザー]

Just a side question for the OP, what's the small square box you've mounted near the clutch master cylinder? I also noticed you had the 3 keys on a key ring sitting on the seat, I hope you don't use the bike with the 3 keys together as Triumph says this could cause problems.

The small black square is the Japanese expressway receiver, the ETC antenna.

 

[Journeyman]

Thanks for the feedback. I'm looking for a time to recheck for leaks. Because the engine isn't working properly, I'm afraid to try high revs. However, when I open the throttle, it stalls.

You just PM me asking about tools need to "repair" the timing chain. We really, really, need more information in order to help you.

• Why, exactly, are you now considering the timing chain?
• Back to my earlier questions, starting with...
• How long have you had it?
• When you did the compression test how did the plugs look?
• Did you or the dealer do the 10k mile service? You're coming up on the 20,000 mile service interval which includes replacing fuel and air filters, spark plugs, valve check, and timing and throttle body adjustments.
• Have you tried riding the bike? How does it perform? Is it fine at higher RPMs, for example?

Ok, you answered the last one. It stalls when you open the throttle. That could be a lot of things TPS, fuel filter, for example. Bad gas in the tank- was it sitting up for a long time?

I personally don't think that "engine leaks" are your issue.

We really need some background information.

Send photos of what you are doing and some lengthy explanation, including answers to above questions, so we can help you.

 

[JAPANユーザー]

You just PM me asking about tools need to "repair" the timing chain. We really, really, need more information in order to help you.

• Why, exactly, are you now considering the timing chain?
• Back to my earlier questions, starting with...
• How long have you had it?
• When you did the compression test how did the plugs look?
• Did you or the dealer do the 10k mile service? You're coming up on the 20,000 mile service interval which includes replacing fuel and air filters, spark plugs, valve check, and timing and throttle body adjustments.
• Have you tried riding the bike? How does it perform? Is it fine at higher RPMs, for example?

Ok, you answered the last one. It stalls when you open the throttle. That could be a lot of things TPS, fuel filter, for example. Bad gas in the tank- was it sitting up for a long time?

I personally don't think that "engine leaks" are your issue.

We really need some background information.

Send photos of what you are doing and some lengthy explanation, including answers to above questions, so we can help you.

I inspected it today. I removed the plug and pumped air through the hole, and found that air was leaking from one of the exhaust valves on the second piston. I've uploaded a video.There is also an air leak on the carburetor side of the third piston.

 

[Kiwicol]

Yeah, did you have the valves in the closed position? I'm picking you took the plugs out then introduced compressed air into the cylinder without making sure the valves were closed. If you put air in without closing the valves of course it's going to let air out, this will be why you got some out of #3 inlet - because it's in the open position.

 

[Gregger]

This may sound obvious but did you ensure both intake and exhaust valves were closed (piston on the power stroke)? We don't want to assume anything here... Is it possible the exhaust valves for that cylinder were on the exhaust stroke when you forced air in the spark plug hole???

 

[Journeyman]

See my earlier comment about decompressors. They always hold the exhaust valves open until started.

You’ve been committed to a compression problem from the start of this thread. I think the solution is going to be something else much much simpler, but we still need some basic questions answered (see above).

 

[Sparky59]

I'm concerned with the color of the exhaust port.....Looks very lean.....NO carbon present.....was or is the valves stuck(from running lean?)
I would spray a light oil WD-40 on the valve shafts and with a spark plug per cylinder removed crank the motor over while watching for smooth valve operation......

 

[JAPANユーザー]

Yeah, did you have the valves in the closed position? I'm picking you took the plugs out then introduced compressed air into the cylinder without making sure the valves were closed. If you put air in without closing the valves of course it's going to let air out, this will be why you got some out of #3 inlet - because it's in the open position.

This bike has four valves in one combustion chamber. When inflating each chamber, I turn the tire to close the valve properly.