Bike runs for two seconds then dies

[motomartin]

Last weekend I rode my RE5 for the first time in a year.
It started easily (surprise) and ran great for 30 miles (some freeway 70 mph and fast country lanes), then cut out while going down a long hill.
The bike would restart for two seconds then cut out. Had to trailer it home.
This weekend I took the carb off and took a quick look at it, it seemed okay. I put the carb back on and it started and ran - yay I've fixed it.
I rode about 100 yards and it cut out. I went to restart and it did the run for two seconds and die routine again.
Any ideas what it might be? Seems like a fuel issue (bike has plenty of gas in it, tried different plugs, the small hoses that go from the carb to the fuel tap and to the secondary diaphragm see okay).
Looking at previous threads it seems like it is the secondary butterfly needs adjusting. I'm pretty sure I've been through this before - I've had this bike for over 11 years now.

[timpa136]

Feb 6, 2022 19:50:02 GMT -5 motomartin said:

Last weekend I rode my RE5 for the first time in a year.
It started easily (surprise) and ran great for 30 miles (some freeway 70 mph and fast country lanes), then cut out while going down a long hill.
The bike would restart for two seconds then cut out. Had to trailer it home.
This weekend I took the carb off and took a quick look at it, it seemed okay. I put the carb back on and it started and ran - yay I've fixed it.
I rode about 100 yards and it cut out. 
Any ideas what it might be? Seems like a fuel issue (bike has plenty of gas in it, tried different plugs, the small hoses that go from the carb to the fuel tap and to the secondary diaphragm see okay).
Looking at previous threads it seems like it is the secondary butterfly needs adjusting. I'm pretty sure I've been through this before - I've had this bike for over 11 years now.

If you mean the port valve, it is unlikely but you can check to see if it closes. I recently had some problems and it was grease on the points. Check them carefully and the connectors. 

[motomartin]

Yes sorry the Port Valve, I was looking at this old thread and it seemed like a similar situation.

re5rotary.proboards.com/thread/2406/re5-start-engine-rotations

[t140v]

Have a look at the points, make sure they are not staying open for a couple of seconds instead of springing closed, are you still using old style plugs or the adaptor.

Regards Stuart.

[motomartin]

Feb 11, 2022 16:00:16 GMT -5 t140v said:

Have a look at the points, make sure they are not staying open for a couple of seconds instead of springing closed, are you still using old style plugs or the adaptor.

Regards Stuart.

Old style plugs still. I'll take a look at the points also - I really haven't looked at them for a long time (but I don't do many miles).
I still think that it's carb / port valve related - the throttle cable seemed to have more play than normal.

Thanks,
Martin

[wayne]

Carb possibly, port valve no. They'll run at low rpm no problems even if you disconnect the port valve and leave it fully closed. Perhaps check that the port valve is not stuck in the fully open position?

[motomartin]

I looked at the points and checked the timing today. I adjusted them both slightly but no large change. The bike starts and runs weakly now for about 5 or 6 seconds.
At one point I had a breakthrough when I changed the plug, it idled strongly for a minute or two before dying. Looking at my motley collection of plugs, it may be time for an adaptor. Stuart do you still have those for sale?

[t140v]

I will be making another batch of 4 this week should be ready Friday.
Regards Stuart

[motomartin]

Stuart, personal message sent.


If this was was regular four stroke I would think the problem was a blocked pilot jet.
I think that is what I will try next.

[wayne]

Please let us know if this sorts your problem.

[motomartin]

Took the carb off again today and looked at it a bit more carefully. I took the primary pilot air jet out (#43 on the parts diagram), held it up to the light and could see just a small amount of light, when I blew down it, a dark carbon looking chunk came out along with a couple of small metal shards. Once I found that, I was pretty sure I had the culprit. Put it back together and it started right up and idles nicely. The question is where did the bits come from, and why did they block the pilot jet during a fairly fast ride where there really wasn't any idling? The carb bowl is clean with no floaters.

[wayne]

Thanks for getting back to us on that. Well done, good find.

I run a paper style filter on my RE5's, I don't believe mesh filters are good enough. Probably just rubbish in your fuel tank?

Put a filter on it if you haven't already.

[motomartin]

Yes, I guess it must be from the gas tank. No I don't currently have a fuel filter. I'll add one, I already have the additional fuel tap, so it's going to look pretty agricultural, all hanging out on top of the carb.

[wayne]

I hear you re the look........ but it beats having crap in the carb.

[motomartin]

That looks like a brand new bike, wow.