[Nick0187]

I have a 1998 vlx that stumbles anytime I roll on the throttle more than 25%. It runs good at idle and when I open the throttle just a bit. when the bike is in neutral and I hit the throttle all of the way, it works pretty good, only when its under load is there an issue. Any ideas?

I have also checked for vacuum leaks and there are none.

 

[Harryc]

Define "stumbles". Do you mean the engine literally bogs down or do you mean you lose power? My first thoughts are loss of spark or clutch slippage. If it were a fuel issue you'd have problems revving out of gear too. How many miles on your VTX?

 

[Nick0187]

By stumbles I mean it bogs down, and it wont raise the rmps. When I keep the throttle on low, it will rev up to higher rpms. I have about 22,000 miles on it.

 

[Harryc]

By stumbles I mean it bogs down, and it wont raise the rmps. When I keep the throttle on low, it will rev up to higher rpms. I have about 22,000 miles on it.

OK, I see. I am going to guess you have a partially plugged main jet or a defective vacuum slide. I'd pull the carbs and rebuild them anyway at that mileage/age if not done before. It's a 17 year old machine.

 

[John Hopkins]

I would remove the in line fuel filter and replace it with a new one, they only cost a few dollars for a generic one, so it won't break the bank.

Then I would cut the old filter in half lengthways to examine the inside for any dirt or debris..

If the old filter is clogged it's a fair bet that the tank needs flushing and that the carbs need stripping and overhauling, if the old fuel filter is clean, take a look at the air filter.

John.

 

[TenDollarBill]

I'm with John on this one. Under load, the engine needs more fuel to rev up than it needs in neutral.

 

[Nick0187]

I have already replaced the fuel filter because it was a cheap solution and could use a new on anyhow, no luck. I guess I'll be pulling apart the carbs and giving them a complete overhaul, probably past due as you said. I hate carbs, im a novice and it always scares me that I'll mess it up..lol.