.. a little help from my friends

[mbeach]

yo mc dudes (and dudetts)

i have a 98 sport star 19 that i am starting to get ready for the season. according to manual, engine is a vortec mx plus 5.0L 305 cid 275 hp. spark plug is the acmr43t and both 142 and 160 thermostats. when i removed one of the existing plugs, it was an acmr43LTS and not the mr43t. now for the questions.

1. do i really have 2 thermostats? i thought i only had the 160 located
under the triangular plate on the front top of the engine.

2. i usually like ngk plugs but the local auto stores are brain dead marine-wise as far as trying to cross reference to ngk. looks like i have 2 choices for the mr43t => yr55 or br6fs and tr5 or tr5gp for the mr43lts plug. any suggestons??

3. i also want to change my fuel filter which is an acgf626. do i have a water separator and if so is there a filter that needs to be changed there also? without pulling the floor boards, it looks like i have 2 grey lines coming from the fuel tank into a device on the left rear of the engine (facing the rear view). from here, 2 lines leave one to the fuel filter and on to the carburetor and the other straight to the right side of the carburetor (rear view). also, looks like this fuel filter is no longer available through the local parts house. they recommend puralotor instead. any comments??

thanks in advance,
monnie beach

[JimN]

1) you have only ome thermostat. The LT-1 has two.
2) You can use NGK if you want, but the MR43LTS has a stainless body and won't rust in. I'm pretty sure the 5.0L Vortec uses the LTS, not the TS, but you should call either a MC dealer or direct to the company to verify this. They work fine. I can't think of a reason to use NGK unless you just can't find the AC. If it was an outboard, I would probably use only NGK.
3) No water separator. There may be a filter on the top of the tank next to the fuel shutoff valve. There is near the motor, before the "device" that is your fuel pump. The pump has a screen at the inlet and if you notice bogging, it will need to be cleaned. Go to a GM dealer for the filter if the local dealer doesn't want to stock AC parts.

You don't have a carburetor, you have throttle body fuel injection. The second fuel line is a return for the unused gas, so it can go back to the tank.

[mbeach]

many thanks jim. this clears some things up. sounds like the only
thing i need to do is change out the fuel filter, correct? are there 2
fuel lines coming into the 'device', aka fuel pump? if so, looks like the
screen will be a real bear to get to. may leave this alone. is the line
pressurized at the canister filter? if so, i guess i need to be somewhat
careful.