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Discussion Starter #1
I picked up an 05 bonneville the wasn't starting for a price low enough to warrant the hassles of fiddling with it. Not to mention that I enjoy tinkering with things and motorcycles are new to me. The only history I know about the bike is what the original owner told me when I bought it. He said it had been running fine, then he was deployed out of the country for a few months. When he was discharged, she wasn't not running and he didn't have time to fiddle with the bike anymore (just him and two kids at home) and he needed the money (no job since leaving military). The bike was turning over, but not firing.

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Details on what I know:

It's an '05 Bonneville with ~13k miles
AI has been removed
It sat dormant for a some period of time
The oil looks clean, but smells slightly of gasoline
The gas is fresh
There's a slow oil leak around the shifter
When running, there's a oil seeping from the left front corner of the valve cover

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First I did the following:

Verified there is spark on both sides
Checked electrical connections
Checked compression (>125 PSI)
Tested Ignition coil and got .6 on the Primary and open circuit on the secondary
Pulled air filter and check for blockage in the airbox
Drained most of the gas out of the tank, and drained the floats and checked for water/sediment
Got her to fire briefly by spraying brake cleaner into the empty airbox

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The coil is suspect, but hearing her fire on brake cleaner lead me to question the state of the carbs. I pulled them and gave them a thorough cleaning per the Haynes manual. The left carb was fairly gunky with varnish. I also found that the idle was set high enough that the butterfly valves were open about an eighth of an inch. I assumed this was way to high, so before reinstalling turned it back to where they were closed. I also replaced the air filter. After reinstalling the carbs, I have finally managed to get to her to run, but only barely.

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Current symptoms now that she "runs":

Will only start with choke fully pulled out.
If you push the choke in at all, she starts struggling and will die.
Idle is *very* erratic.
If I give her the tiniest bit of throttle, she will rev, but any more and the engine dies.
There appears to be gas seeping out of both throttle plungers.
I rechecked the spark plugs and found them both fouled with soot so she's running with a rich fuel/air mixture (not surprising with the choke on)
There is a small amount of white smoke coming out near the spark plugs and from the underside of the clutch cover.
Occasionally, there will be a quick puff of white smoke vented at high pressure from the left hand carb around the rubber connected the carb to the engine.

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What I've done to troubleshoot this:

Tried adjusting the idle speed - too much either direction and she dies and doesn't restart.
Made small adjustments both directions to the carb sync screw with no improvement.
Shut off petcock while she was running to see if there was any change as the float chambers ran out of fuel (no change other than the usual struggling when running out of gas)
Checked that the throttle cable was reconnected properly.
Checked the seals on both ends of boths carbs and all vacuum caps.
Sprayed WD40 in various places to listen for the engine to rev signalling a vacuum leak, but noticed no change.

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I'm rapidly running out of ideas and things to check. It would seems the she only wants to run with a super rich fuel/air mixture, and with anything less she dies. I can order a new ignition coil, but I'm not sure how that would relate to fuel/air mixture (although I don't know a ton about all this at the moment). I have tubing to rig up a basic carb sync tool to check if it's way off, and if I way a vacuum problem on one of the carbs. I am waiting to get a new clutch cover gasket in later this week so I can drain the oil and replace it for that oil leak. While the oil is drained, I plan to check the valve clearances and instpect the pickup coil while I have the crank cover off. I picked up some copper tubing to see about fashioning a D tool to check where the idle air screws are set at and if out of spec, put them back to 2.5 turns out.

I would greatly appreciate any thoughts anyone has about what else I should look into.

Brian
 

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There is no point in balancing carbs and all this other work when you have fuel leaking out of your carbs. Fix the visible issues first then go deeper. It sounds to me like carb issues. When something sits for so long its the carbs that messed up first since nothing else is running. Fix your carb and engine leaks. Does this bike have any mods done? AI removed, airbox removed or performance exhaust?
 

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Discussion Starter #3
The AI was removed and exhaust changed by previous owner. The AI removal appears to be done right when looking at instructions online for the process.

I am still suspecting the carbs. I did get everything squeaky clean though. And the diaphragms looked to be in good shape. I am somewhat confused by gas coming out of the choke plungers. How does that much get all the way up there?
 

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Discussion Starter #4
I went ahead and picked up an OEM ignition coil. it appears the Nology ones are as rare as hen's teeth at the moment. One supplier said they weren't expecting any more until February. I won't get to swap out the coil until tomorrow but I'll report the results. I also picked up a valve cover seal but the dealer is still waiting on the clutch cover seal to arrive so all the seals will have to wait for that one before I drain the oil.
 

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There is no point in balancing carbs and all this other work when you have fuel leaking out of your carbs.
+1

Check the float needle valves & valve seats aren't all gummed up. Maybe you missed this on the carb rebuild. The are some good thread on this subject on the forum - try searching.

If she runs now on choke but dies without it maybe you could try dialing in a bit more idle adjustment.
 

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Discussion Starter #6
@Gary -

I did check and clean the float needles when I did the carbs. The looked good when I put everything back together. It's possible I did not get the float height set right since that seemed to be pretty easy to muck up. I'll double check that after I swap the coil tomorrow. I will say I've searched a bunch on here and found bits and pieces of my troubles and all pointing to various things as to what the problem is/was. It is very possible that I have multiple issues going on at once, which is always a pain to troubleshoot. I work in IT, so am familiar with general technical problem solving.
 

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You probably have dirty gas someplace still. Check the fuel vent tube. Replace the gas in the tank again, add some Sea Foam and try that. Go over the carbs again. Clean the fuel petcock and gas line, and filter.
 

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Discussion Starter #8
All new gas, Sea Foam, and cleaning the petcock, gas line, and filter are all added to my to do list for tomorrow.
 

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All new gas, Sea Foam, and cleaning the petcock, gas line, and filter are all added to my to do list for tomorrow.
Don't forget the Fuel Tank Vent Tube as W-850 stated. This has been known to give fits. Sorry if you stated this already but did you try pulling your fuel tank cap off while idling? If she comes alive then the vent tube is likely plugged. Also, while it's running...move petcock from normal to reserve and see if fuel flow increases/idles better. If so, petcock has mung in it. Cost is low enough that I would just replace the inline fuel filter if it has one. Tough to clean. Sounds like you did a bang up job on the carbies but the pilot circuits may still have the tiniest of goop in them. Did you replace your pilot jets or just clean them? May not hurt to put in new.... relatively inexpensive.
Good luck.
 

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Discussion Starter #10
I did think to try both normal and reserve, as well as opening the gas cap. I held the pilot jets up to a light and inspected all the holes and everything "appeared" to be completely clear. I saw a perfect circle of light through everything.
 

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Discussion Starter #12
Update:

New ignition coil didn't fix anything, but at least I'm confident it's good. I'm reading close to the stated specs in Haynes so that's good at least.

It seems something got fouled up on one of the floats that was causing the gas leak in the carbs. I took off the tops on both and things looked clean. I drained and removed the float chambers on both and inspected everything and it looked good. Drained the tank, removed and cleaned out the petcock. Checked the intake and gas lines for the tank and things were clear. Rinsed out the tank with fresh gas and then put in a gallon plus an ounce of sea foam. I checked the vacuum caps, and also verified there was vacuum by taking some clear tubing and seeing if it would suck some sea foam out of the bottle. I had vacuum on both intakes.

Currently, she's only idling for a few seconds and then dying any time I start her. She still only even does that when the choke is pulled out. If I push the choke in, she dies immediately. If I try to give her some throttle, she dies.

One thing I noticed is that the starter sounds like it's spinning faster with the choke off. Is that typical or a symptom of something?
 

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Discussion Starter #13
Also, occasionally when she's trying to start, there's an odd sorted of "venting gas" sound. like a seal is not folding. It's not every time, and it doesn't seem to be coming from the same place every time.
 

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There is a metal tube between the carbs that connects them. It is T shaped with the end of the T shape sticking up. In stock form it has a rubber tube running off it and down the center frame tube. Take off the rubber tube if it still has one and make sure the T shape metal tube is clear and open. If it is not, it will have the same effect on the bike as you are experiencing.
 

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Is it possible that before you bought the bike someone adjusted valve clearances and either got that badly wrong or perhaps set the valve timing a tooth out ( not sure if it would run at all with incorrect valve timing ).
But if you are puffing white smoke from odd places and hearing a "venting gas sound" then its something i would look at.
 

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Are the needle jets properly installed on top of the needle jet holder? Should have conical end facing up toward the needle.
 

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Discussion Starter #18
The needle jet holder only wanted to go back in the one way. It was oriented where the end that has a bit of a bowl cut out of it is facing up towards the needle. The end that was smoothed over was down towards the float chamber.
 

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Discussion Starter #19
So this morning she's reving finally. And after playing with the idle screw, I can actually get her to start with the choke pushed in some of the time. When giving throttle, there's a lot of lag between twisting the throttle and having it rev. Sometimes, she still dies when giving her gas.

Also, she's generally smoking all over, and when the revs are up, there's definitely white smoke getting vented out of the left intake rubber seal. There's still holes in my understanding of all this, but I thought there shouldn't be that much positive pressure inside that rubber connecting the carb to the engine intake. It's like exhaust is being pushed back into the carb instead of being vented the right way. I'm thinking I will need to inspect the valves and timing.
 

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Valve timing for sure and it might be wise to have a look at those intake boots. Do you have manifold leaks? I mean you must if you are seeing smoke out of the boots.... Those should be airtight otherwise the engine is sucking in air after the carbs and after the fuel..... Won't run with bad vacuum leaks.
 
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