Author Topic: what happened to my motor?  (Read 1504 times)

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LeoLegendATL

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what happened to my motor?
« on: October 04, 2005, 05:22:14 PM »
Had just finished putting new hose clamps on my carb boots, took apart the carbs, cleaned em then did a carb sync.  Took the bike down my street and proceed to pull out onto the road and gave it WOT, climbed very nicely to 6,7,8 rpms, then the bike sputtered and bogged down and began running with about half the power.  Engine sounded much deeper and I limped back home, it seems to idle ok so I pulled the plugs to find number 4 bent in to the point where a gapper couldn't go through!  I regapped it and checked that the valves were turning freely, they were ok. then fired it up again only to find that the engine is indeed running smoothly but it just seems to have about half the normal power, revs ok and everything.  I did my own vavle settings and timing as I ran the bike this morning for about 30 miles with no problem, so I don't think it;s the vavles.  anyone have any ideas?  I pulled all the plugs, number 1 is carbon fouled but the others ok. Help!

Offline mrblasty

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Re: what happened to my motor?
« Reply #1 on: October 04, 2005, 05:33:30 PM »
check to make sure the main jets are in place, my neighbors bike was doing the same thing. I took off the float bowl and the jet was
rolling around inside the float bowl
I farted and made my son cry.
1973 Honda CB 750
1975 GL 1000
1975 Yamaha XS650 The Swamp Donkey

sixshooter

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Re: what happened to my motor?
« Reply #2 on: October 04, 2005, 05:57:12 PM »
sounds like something got on top of the piston maybe while carbs were off.

LeoLegendATL

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Re: what happened to my motor?
« Reply #3 on: October 04, 2005, 07:22:08 PM »
well, I think I may have found the problem, 2 and 3 aren't firing anymore, cold pipes it seems.  So what is my next step here?  I trimmed the ends of the plug wires and recapped em in the plug caps so Im getting good connections.  So I guess the coils is the next step?  Any way to test them? do they just go bad like this or do you think there are electrical probs.  Sorry if I sound excited, I hate having my bike not run!

Offline Cvillechopper

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Re: what happened to my motor?
« Reply #4 on: October 04, 2005, 07:45:17 PM »
Have you narrowed it down to fire (tested to make sure spark is getting through on 2 and 3)?  You could have spark and no fuel which would lead to cold pipes.  Also, they run off the same set of points so I'm thinking you might want to check gap just to make sure something didn't happen at the source.  Can't hurt to make sure.  Just an idea...

James
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LeoLegendATL

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Re: what happened to my motor?
« Reply #5 on: October 04, 2005, 08:57:56 PM »
thanks a bunch, I found out the problem.  One of the adjustment screws on my points plate for 2 and 3 was touching a wire and grounding out the 2 and 3 circuit.  Move the plate a bit, and, hot pipes! However I did hook up the timing light to number three and was getting erratic light from the gun, not the usual strobe.  So I suspect something is still off a bit.  Could my 2 and 3 points plate be fried?  Or could this be a plug problem, they seem pretty fouled, would fouled plugs cause an erratic spark?

Offline Raul CB750K1

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Re: what happened to my motor?
« Reply #6 on: October 05, 2005, 12:44:06 AM »
If there was no spark then no wonder the plugs are fouled. All the gas come through them unburnt.

Raul

Offline Mark M

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Re: what happened to my motor?
« Reply #7 on: October 05, 2005, 01:46:43 AM »
You can check your plugs by swapping them about to see if the problem moves with them.
In the UK anything over 40 years old only needs insurance and Fuel.

Offline Cvillechopper

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Re: what happened to my motor?
« Reply #8 on: October 05, 2005, 03:23:14 AM »
Make sure to check the condition and gap of your points as well.  If their damaged from the loose plate you'll get eratic spark. 
It is the mark of an educated mind to be able to entertain a thought without accepting it.  Aristotle