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maxmonster

Member
Joined
Jul 3, 2024
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Location
North Royalton,OH USA
Where to begin,hmm. Max decided to start running poor yesterday. Idle would have a slight surge of about 200rpm and it would stutter on acceleration from idle to 2700rpm then have normal smooth power above that. Put fresh NKG plugs in, took carbs off and cleaned all the jets. Put the carbs back on and synced them and set my a/f mixtures. While syncing carbs I had low vacuum, under 5lbs on all carbs. Checked v-boost and it was adjusted properly so didn't mess with it. When I took the vacuum port plugs off carbs for cylinder 2 and 4 to hook up gauges it wanted to die. When I took the port plugs off 1 and 3 there was no rpm change.
After syncing it was idling good sounded good. Problem solved? I think not. Took the bike for a ride about a mile stopped for gas and everything was going good. Left the gas station and about 2 miles later issues started. When came to a stop light it didn't want to Idle and died. Headed back towards home and had sputtering below 3000rpm when I let off the throttle and also ran like crap below 3000rpm. Bike has 21k miles and thought I would check my timing today. Hooked up my timing light, took off the inspection cover and fired the bike, oil blew out the hole and onto the floor. Oh no. Shut the bike off and took the flywheel nut cover off and oil came out. Before I get any further into it what can be my issue? Is there a crankshaft seal back there behind everything? I have a Clymer manual but don't see a seal on any crankshaft diagram.
 

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everything under the flywheel cover is lubed by engine oil. There is no crankshaft oil seal. Timing is fixed by the flywheel key and is not adjustable without replacing with an offset flywheel key. The inspection hole is for setting cam timing. Sounds like carb issues. Or bad gas.
 
Oh OK I didn't think that there would be oil inside there or come shooting out when when I tried to use the timing light. I've owned the bike for 8 years and have always wondered is the previous owners changed the jetting. Bike is stock exhaust and stock air filter, I'm at 800ft above sea level, what would be proper jet for me to run or the stock jets? I replaced the diaphrams 2 years ago due to one of them having cracks.
 
The bolt in the center of the flywheel has an oil flinger/pump to mist the outer cover which in turn reflects it over the stator for cooling. The timing access is the small nickle sized plug in front of the cover. But, the bike will not be out of time.
Likely you have either carb or electrical issues.
Almost sounds like you are describing the pump either not working, the fuel low and res switch in the wrong position, or out of fuel.
 
From what you describe it would appear that cleaning the carbs initially sorted the problem but further contamination has been drawn in.
When was the fuel filter last changed? Have you looked into the tank to check for signs of corrosion?
 
Full tank new gas, fuel switch in normal position. I haven't changed the fuel filter since I bought it 8 years ago. Shined a light in the tank and don't see any rust but guess there could be dirt in the bottom. I'll have to empty the tank out and flush it. Is there a fuel filter that is better than others to replace my current one with? I checked all the cylinders for spark today and all had a nice blue ark, plugs gapped at .032in.
 
Are you certain the pilot fuel jets are clean?
All jets were clean and open when I put them back together and on the bike. I ordered 2 fuel filters this morning so when those come I'll be draining the tank, installing a new filter, and taking the carbs back off and cleaning again and checking the float levels.
 
All jets were clean and open when I put them back together and on the bike. I ordered 2 fuel filters this morning so when those come I'll be draining the tank, installing a new filter, and taking the carbs back off and cleaning again and checking the float levels.
I've had trouble with dirt plugging my carbs even with a new gas tank and OEM filter. I found a 10 micron sintered brass cleanable filter at Summit Racing. It's made by Earls and runs about $30 after shipping. I cut it into the line between the stock fuel filter and the fuel pump. It fits nicely just in front of the battery. A little tough to access but I don't mind. I haven't run it long enough to be sure it will solve my problem but so far so good.

Remember to drain fill drain your carbs until the gas is clean. I use a glass bowl on white paper to check for specks of stuff.
 
Tore the carbs apart and 2 of the smallest long jets were plugged, got those cleared. Checked the floats and they were all adjusted to 28.5mm. Replaced the fuel filter and flushed the tank. Put the bike back together and synced the carbs, vacuum at 1100rpm went up to 5.5lbs on all carbs. Idle was nice and had smooth rev. Took her out for a ride and ran great. Rode her for two days in a row to work with no more issues, except for the forks bottoming out on big bumps so I ordered a set of progressive springs which just got delivered today so that will be the project for this weekend. Thanks guys
 

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