Gumshu 0 #1 Posted October 4, 2018 Hey guys, I just replaced the carb and fuel pump on my 310-8. I have it adjusted and it runs smoothly but it seems like I don’t have the same amount of rpm’s at full throttle. Anyone have any ideas? I got everything from the isavetractors guy. I do have an email into him but thought I’d stop here while I wait. I changed the carb and pump because I was getting fuel in the oil. Share this post Link to post Share on other sites
The Tuul Crib 7,331 #2 Posted October 4, 2018 40 minutes ago, Gumshu said: Hey guys, I just replaced the carb and fuel pump on my 310-8. I have it adjusted and it runs smoothly but it seems like I don’t have the same amount of rpm’s at full throttle. Anyone have any ideas? I got everything from the isavetractors guy. I do have an email into him but thought I’d stop here while I wait. I changed the carb and pump because I was getting fuel in the oil. Points condenser and plugs. .20 Gap on the points at top dead center . That's what I will try next Share this post Link to post Share on other sites
oldredrider 2,547 #3 Posted October 4, 2018 Try gapping the points at .020. It will work much better. 2 1 Share this post Link to post Share on other sites
Gumshu 0 #4 Posted October 5, 2018 (edited) Why would it need replaced if it was running fine with the exception on fuel in the oil previously? I’m not doubting anyone. I’m just trying to understand. Back story- I discovered fuel in the oil and the occasional back fire at shut down. A repair guy told me to replace the carb and pump. No previous issue with wide open engine rpm. I replace both and tune it as perfect as possible. I notice the rpm at full throttle are just not where they used to be “by ear” not measured by a gauge. I know, very scientific. What is the blade speed speed supposed to be? Edited October 5, 2018 by Gumshu Share this post Link to post Share on other sites
ELECTRORIC 228 #5 Posted October 5, 2018 Did you adjust the governor when you replaced the carb? Share this post Link to post Share on other sites
Gumshu 0 #6 Posted October 5, 2018 I didn’t touch anything other than the carb and fuel pump. Share this post Link to post Share on other sites
oliver2-44 8,772 #7 Posted October 5, 2018 There is a wide open throttle stop as part of the linkage that is adjusted to set Max RPM. While you may not have changed it, your new carb and corresponding linkage hookup might just be slightly different enough that this max rpm limiter needs to be checked. The carb mounting bolt holes are slotted, so if your new carb is shifted slightly different than exactly where the old one sat, that could be enough of a difference. Sorry I don't have a good diagram to point to, so maybe one of the othe guys will jump in here with a better description or diagram. 1 1 Share this post Link to post Share on other sites
elcamino/wheelhorse 8,945 #8 Posted October 5, 2018 @Gumshu does your 310 have a Magnum 10 hp motor , if so no points. 2 Share this post Link to post Share on other sites
Gumshu 0 #9 Posted October 5, 2018 It is the magnum. Share this post Link to post Share on other sites
Gumshu 0 #10 Posted October 5, 2018 (edited) The linkage moves the full throw on top of the carb when the engine is off. When it’s running it barely moves when I work the throttle. The engine responds to the throttle, it just doesn’t move as it does when the engine is off. I’ll try for a quick video tomorrow. Edited October 5, 2018 by Gumshu Share this post Link to post Share on other sites
dells68 7,494 #11 Posted October 5, 2018 The governor controls the throttle movement when the engine is running and will appear to reduce the travel of the throttle linkage. Your cable should have the same range of motion, running or not, the governor manages the throttle linkage movement. 2 Share this post Link to post Share on other sites
Anglo Traction 759 #12 Posted October 5, 2018 10 hours ago, Gumshu said: Why would it need replaced if it was running fine with the exception on fuel in the oil previously? I’m not doubting anyone. I’m just trying to understand. What is the blade speed speed supposed to be? Depends what Deck you are running!. Did calcs on my 36" RD to check bearing specs and gave these results- Full engine speed (recommended) 3500 rpm, PTO pulley 4" dia, Mower Deck Driver pulley 4" dia , Driven 4" driving 14inch dia centre Blade = tip speed of 145.83 MPH (@ 3500rpm) Outer 12inch Blades with 3 inch Pulleys= (3500rpm x 1.25) tip speed of 156.25 mph @ 4375rpm. 1 Share this post Link to post Share on other sites
Gumshu 0 #13 Posted October 5, 2018 (edited) I guess the Next step is checking engine rpm. I just ordered an hour meter/tach. That’ll be good enough to tell me if I’m getting 3500 out of the engine. I’ll keep you guys posted. Edited October 5, 2018 by Gumshu Share this post Link to post Share on other sites