98 Sportster 1800 Lagging, bogging, stalling

[blackwellchris2000]

Well, I'm back on SDF so there must be a problem lol. At the end of last year we had issues with the left motor bogging down and not wanting to go above 3K RPMS. Then it sort of jumps between high and low RPMS and finally wouldn't really do much. So after winter, I pulled both carbs since we'd had a similar issue before and cleaning the carbs fixed it. Well, I pulled them both, cleaned them both (even though it was only the left motor) and guess what. Damned thing did the same thing, and now the right motor wants to stall unless you keep it throttled up to about 2500 RPMS. Anyone had a similar issue or any ideas as to what in the hell is going on? :banghead:

 

[jhjesse]

Well, I'm back on SDF so there must be a problem lol. At the end of last year we had issues with the left motor bogging down and not wanting to go above 3K RPMS. Then it sort of jumps between high and low RPMS and finally wouldn't really do much. So after winter, I pulled both carbs since we'd had a similar issue before and cleaning the carbs fixed it. Well, I pulled them both, cleaned them both (even though it was only the left motor) and guess what. Damned thing did the same thing, and now the right motor wants to stall unless you keep it throttled up to about 2500 RPMS. Anyone had a similar issue or any ideas as to what in the hell is going on? :banghead:

Since you have already cleaned the carbs don't stop there...Clean or replace the fuel selector valve, clean the fuel filters/water seperators. Clean or replace the external fuel pumps, pull the fuel baffle and check for gunk on the bottom screen.

Make sure fuel filter/seperator 0 ring seats properly or you will get air in the system. Also make sure the vent check valve is not clogged.
The complete fuel system probably needs cleaning and not just the carbs. Chances are better that good that whatever was in the carbs is all through the fuel system. I would do all this before attempting to run the engines again, otherwise you could blow a piston running it to lean.

I would also run a compression test. 140-150psi.

 

[blackwellchris2000]

Ran through the fuel system as far as filters, etc. In actuality, the carbs didn't look all that bad. Very little in the internal fuel filters. I was thinking fuel pumps as well, but just the whole timing of it seems odd. I guess I'll try some plugs as a quick hail mary options and then check out the pumps. I've needed to pull the fuel baffle for years since our gas gauge won't work, but I've head that's a monster of a project so I've been hesitant to do so. Any thoughts on this?